History of United States foreign policy

North America after the Treaty of Paris. The United States (blue) was bordered by the United Kingdom (yellow) to the north and Spain (brown) to the south and west.

From the establishment of the United States after regional, not global, focus, but with the long-term ideal of creating an "Empire of Liberty."

The military and financial alliance with France in 1778, which brought in Spain and the Netherlands to fight the British, turned the American Revolutionary War into a world war in which the British naval and military supremacy was neutralized. The diplomats—especially Franklin, Adams and Jefferson—secured recognition of American independence and large loans to the new national government. The Treaty of Paris in 1783 was highly favorable to the United States which now could expand westward to the Mississippi River.

Historian Samuel Flagg Bemis was a leading expert on diplomatic history. According to Jerold Combs:

Bemis's The Diplomacy of the American Revolution, published originally in 1935, is still the standard work on the subject. It emphasized the danger of American entanglement in European quarrels. European diplomacy in the eighteenth century was "rotten, corrupt, and perfidious," warned Bemis. America's diplomatic success had resulted from staying clear of European politics while reaping advantage from European strife. Franklin, Jay, and Adams had done just this during the Revolution and as a consequence had won the greatest victory in the annals of American diplomacy. Bemis conceded that the French alliance had been necessary to win the war. Yet he regretted that it had brought involvement with "the baleful realm of European diplomacy." Vergennes [the French foreign minister] was quite willing to lead America to an "abattoir" [slaughterhouse] where portions of the United States might be dismembered if this would advance the interests of France.[1]

American foreign affairs from independence in 1776 to the new Constitution in 1789 were handled under the Articles of Confederation directly by Congress until the new government created a department of foreign affairs and the office of secretary for foreign affairs on January 10, 1781.[2]

The Jay Treaty of 1795 aligned the U.S. more with Britain and less with France, leading to political polarization at home

The cabinet-level Department of Foreign Affairs was created in 1789 by the First Congress. It was soon renamed the Department of State and changed the title of secretary for foreign affairs to Secretary of State; Thomas Jefferson returned from France to take the position.

When the French Revolution led to war in 1793 between Britain (America's leading trading partner), and France (the old ally, with a treaty still in effect), Washington and his cabinet decided on a policy of neutrality. In 1795 Washington supported the Jay Treaty, designed by Treasury Secretary Alexander Hamilton to avoid war with Britain and encourage commerce. The Jeffersonians vehemently opposed the treaty, but Washington's support proved decisive, and the U.S. and Britain were on friendly terms for a decade. However the foreign policy dispute polarized parties at home, leading to the First Party System.[3][4]

In a "Farewell Message" that became a foundation of policy President George Washington in 1796 counseled against foreign entanglements:[5]

Europe has a set of primary interests, which to us have none, or a very remote relation. Hence she must be engaged in frequent controversies, the causes of which are essentially foreign to our concerns. Hence therefore it must be unwise in us to implicate ourselves, by artificial ties, in the ordinary vicissitudes of her politics, or the ordinary combinations & collisions of her friendships, or enmities. Our detached & distant situation invites and enables us to pursue a different course.

By 1797 the French were openly seizing American ships, leading to an undeclared war known as the Quasi-War of 1798–99. President John Adams tried diplomacy; it failed. In 1798, the French demanded American diplomats pay huge bribes in order to see the French Foreign Minister Talleyrand, which the Americans rejected. The Jeffersonian Republicans, suspicious of Adams, demanded the documentation, which Adams released using X, Y and Z as codes for the names of the French diplomats. The XYZ Affair ignited a wave of nationalist sentiment. Overwhelmed, the U.S. Congress approved Adams' plan to organize the navy. Adams reluctantly signed the Alien and Sedition Acts as a wartime measure. Adams broke with the Hamiltonian wing of his Federalist Party and made peace with France in 1800.[6]

USS Constitution surprised analysts with an important victory over HMS Guerriere in 1812.

The Jeffersonians deeply distrusted the British in the first place, but the British shut down most American trade with France, and impressed into the Royal Navy about 6000 sailors on American ships who claimed American citizenship. American honor was humiliated by the British attack on the American warship Chesapeake in 1807.[9]

In the west, Indians supported and armed by Britain used ambushes and raids to kill settlers, thus delaying the expansion of frontier settlements into the Midwest (Ohio, Indiana, and Michigan, especially).[10]

In 1812 diplomacy had broken down and the U.S. declared war on Britain. The War of 1812 was marked by very bad planning and military fiascoes on both sides. It ended with the Treaty of Ghent in 1815. Militarily it was a stalemate as both sides failed in their invasion attempts, but the Royal Navy blockaded the coastline and shut down American trade (except for smuggling supplies into British Canada). However the British achieved their main goal of defeating Napoleon, while the American armies defeated the Indian alliance that the British had supported, ending the British war goal of establishing a pro-British Indian boundary nation in the Midwest and giving them territorial advantage over the U.S. The British stopped impressing American sailors and trade with France (now an ally of Britain) resumed, so the causes of the war had been cleared away. Especially after the great American victory at the Battle of New Orleans, Americans felt proud and triumphant for having won their "second war of independence."[11] Successful generals Andrew Jackson and William Henry Harrison became political heroes as well. After 1815 tensions de-escalated along the U.S.-Canada border, with peaceful trade and generally good relations. Boundary disputes were settled amicably. Both the U.S. and Canada saw a surge in nationalism and national pride after 1815, with the U.S. moving toward greater democracy and the British postponing democracy in Canada.

After 1780 The United States opened relations with North African countries, and with the Ottoman Empire.[12]

In response to the new independence of Spanish colonies in Latin America in 1821, the United States established the Monroe Doctrine in 1823. This policy declared opposition to European interference in the Americas and left a lasting imprint on the psyche of later American leaders. The failure of Spain to colonize or police Florida led to its purchase by the U.S. in 1821. John Quincy Adams was Secretary of State under President Monroe.[13]

The United States annexed the Republic of Texas and acquired Oregon Country and the Mexican cession during the presidency of James K. Polk (1845–1849)

In 1846 after an intense political debate in which the expansionist Democrats prevailed over the Whigs, the U.S. annexed the Republic of Texas. Mexico never recognized that Texas had achieved independence and promised war should the U.S. annex it. President James K. Polk peacefully resolved a border dispute with Britain regarding Oregon, then sent U.S. Army patrols into the disputed area of Texas. That triggered the Mexican–American War, which the Americans won easily. As a result of the Treaty of Guadalupe Hidalgo in 1848 the U.S. acquired territory that included California, Arizona and New Mexico, and the Hispanic residents there were given full U.S. citizenship.[14]

The British wanted a stable Mexico to block American expansion to the Southwest, but an unstable Mexico attacked Texas and wanted revenge for its defeat. The result was a vast American expansion. The discovery of gold in California in 1848 brought a heavy demand for passage to the gold fields, with the main routes crossing Panama to avoid a very long slow sailing voyage around all of South America. A railroad was built that carried 600,000 despite the dangerous environment in Panama. A canal in Nicaragua was a much more healthier and attractive possibility, and American businessman Cornelius Vanderbilt gained the necessary permissions, along with a U.S. treaty with Nicaragua. Britain had long dominated Central America, but American influence was growing, and the small countries look to the United States for protection against British imperialism. However the British were determined to block an American canal, and seized key locations on the Miskito coast on the Atlantic that blocked it. The Whigs were in charge in Washington and unlike the bellicose Democrats wanted a business-like peaceful solution. The Whigs took a lesson from the British experience monopolizing the chokepoint of Gibraltar, which produced no end of conflicts, wars, and military and naval expenses for the British. The United States decided that a canal should be open and neutral to all the world's traffic, and not be militarized. Tensions escalated locally, with small-scale physical confrontations in the field.[15]

In the Clayton–Bulwer Treaty of 1850 Washington and London found a diplomatic solution. To avert an escalating clash it focused on a Nicaragua Canal that would connect the Pacific and the Atlantic. The three main treaty provisions stated that neither nation would build such a canal without the consent and cooperation of the other; neither would fortify or found new colonies in the region; if and when a canal was built, both powers would guarantee that it would be available on a neutral basis for all shipping. However, disagreements arose and no Nicaragua canal was ever started, but the treaty remained in effect until 1901. By 1857–59, London dropped its opposition to American territorial expansion.[16]

The opening of the transcontinental railroad in 1869 made travel to California fast, cheap and safe. Americans lost interest in canals and focused their attention on building long-distance railways. The British, meanwhile, turned their attention to building the Suez Canal through Egypt. London maintained a veto on American canal building in Nicaragua. In 1890s, the French made a major effort to build a canal through Panama, but it self-destructed through mismanagement, severe corruption, and especially the deadly disease environment. By the late 1890s Britain saw the need for much improved relations with the United States, and agreed to allow the U.S. to build a canal through either Nicaragua or Panama. The choice was Panama. The Hay–Pauncefote Treaty of 1901 replaced the Clayton–Bulwer Treaty, and adopted the rule of neutralization for the Panama Canal which the U.S. built; it opened in 1914.[17][18]

Buchanan had a great deal of experience in foreign policy and entered the White House with an ambitious foreign policy, but he And Secretary of State Lewis Cass had very little success. The primary obstacle was opposition from Congress. His ambitions centered around establishing U.S. hegemony over Central America at the expense of Great Britain.[19] He hoped to re-negotiate the Clayton-Bulwer Treaty, which he viewed as a mistake that limited U.S. influence in the region. He also sought to establish American protectorates over the Mexican states of Chihuahua and Sonora, In part as a destination for Mormons.[20]

Aware of the decrepit state of the Spanish Empire, he hoped to finally achieve his long-term goal of acquiring Cuba, where state slavery still flourished. After long negotiations with the British, he convinced them to agree to cede the Bay Islands to Honduras and the Mosquito Coast to Nicaragua. However, Buchanan's ambitions in Cuba and Mexico were blocked in the House of Representatives where the anti-slavery forces strenuously opposed any move to acquire new slave territory. Buchanan was assisted by his ally Senator John Slidell (D.-Louisiana) But Senator Stephen Douglas, a bitter enemy of Buchanan inside the Democratic Party worked hard to frustrate Buchanan's foreign-policy.[21][22]

Buchanan tried to purchase Alaska from Russia, possibly as a colony for Mormon settlers, but the U.S. and Russia were unable to agree upon a price.

In China, despite not taking direct part in the Second Opium War, the Buchanan administration won trade concessions. The president relied on William Bradford Reed (1806–1876) his Minister to China in 1857–58. A former Whig, Reed had persuaded many old-line Whigs to support Buchanan In 1856 campaign. The Treaty of Tientsin (1858) granted American diplomats the right to reside in Peking, reduced tariff levels for American goods, and guaranteed the free exercise of religion by foreigners in China. Reed developed some of the roots of the Open Door Policy that came to fruition 40 years later.[23][24]

In 1858, Buchanan was angered by "A most unprovoked, unwarrantable, and dastardly attack" and ordered the Paraguay expedition. Its successful mission was to punish Paraguay for firing on the USS Water Witch which was on a scientific expedition. Paraguay apologized and paid an indemnity.[25]

Every nation was officially neutral throughout the American Civil War, and none recognized the Confederacy. That marked a major diplomatic achievement for Secretary Seward and the Lincoln Administration. France, under Napoleon III, had invaded Mexico and installed a puppet regime; it hoped to negate American influence. France therefore encouraged Britain in a policy of mediation suggesting that both would recognize the Confederacy.[26] Lincoln repeatedly warned that meant war. The British textile industry depended on cotton from the South, but it had stocks to keep the mills operating for a year and in any case the industrialists and workers carried little weight in British politics. Knowing a war would cut off vital shipments of American food, wreak havoc on the British merchant fleet, and cause the immediate loss of Canada, Britain, with its powerful Royal Navy, refused to go along with French schemes.[27]

Lincoln's foreign policy was deficient in 1861 in terms of appealing to European public opinion. Diplomats had to explain that United States was not committed to the ending of slavery, but instead they repeated legalistic arguments about the unconstitutionality of secession. Confederate spokesman, on the other hand, were much more successful by ignoring slavery and instead focusing on their struggle for liberty, their commitment to free trade, and the essential role of cotton in the European economy. In addition, the European aristocracy (the dominant factor in every major country) was "absolutely gleeful in pronouncing the American debacle as proof that the entire experiment in popular government had failed. European government leaders welcomed the fragmentation of the ascendant American Republic."[28]

Elite opinion in Britain tended to favor the Confederacy, while public opinion tended to favor the United States. Large scale trade continued in both directions with the United States, with the Americans shipping grain to Britain while Britain sent manufactured items and munitions. Immigration continued into the United States. British trade with the Confederacy was limited, with a trickle of cotton going to Britain and some munitions slipped in by numerous small blockade runners. The Confederate strategy for securing independence was largely based on the hope of military intervention by Britain and France, but Confederate diplomacy proved inept. With the announcement of the Emancipation Proclamation in September 1862, it became a war against slavery that most British supported.[29]

A serious diplomatic dispute with the United States erupted over the "Trent Affair" in late 1861. Public opinion in the Union called for war against Britain, but Lincoln gave in and sent back the diplomats his Navy had illegally seized.[30]

British financiers built and operated most of the blockade runners, spending hundreds of millions of pounds on them; but that was legal and not the cause of serious tension. They were staffed by sailors and officers on leave from the Royal Navy. When the U.S. Navy captured one of the fast blockade runners, it sold the ship and cargo as prize money for the American sailors, then released the crew.

A long-term issue was the British shipyard (John Laird and Sons) building two warships for the Confederacy, including the CSS Alabama, over vehement protests from the United States. The controversy was resolved after the Civil War in the form of the Alabama Claims, in which the United States finally was given $15.5 million in arbitration by an international tribunal for damages caused by British-built warships.[31]

In the end, these instances of British involvement neither shifted the outcome of the war nor provoked either side into war. The U.S. diplomatic mission headed by Minister Charles Francis Adams, Sr. proved much more successful than the Confederate missions, which were never officially recognized.[32]

Historian Don Doyle has argued that the Union victory had a major impact on the course of world history.[33] The Union victory energized popular democratic forces. A Confederate victory, on the other hand, would have meant a new birth of slavery, not freedom. Historian Fergus Bordewich, following Doyle, argues that:

The North's victory decisively proved the durability of democratic government. Confederate independence, on the other hand, would have established An American model for reactionary politics and race-based repression that would likely have cast an international shadow into the twentieth century and perhaps beyond."[34]

As Secretary of State, William Seward presided over the acquisition of Alaska

Relations with Britain (and Canada) were tense; Canada was negligent in allowing Confederates to raid Vermont. Confederation came in 1867, in part as a way to meet the American challenge without depending on British armed forces.[35]

The U.S. looked the other way when Irish activists known as Fenians tried and failed badly in an invasion of Canada in 1871. The Fenians movement collapsed from its own incompetence.[36] The arbitration of the Alabama Claims in 1872 provided a satisfactory reconciliation; The British paid the United States $15.5 million for the economic damage caused by Confederate warships purchased from it.[37] Congress did pay Russia for the Alaska Purchase in 1867, but otherwise rejected proposals for any major expansions, such as the proposal by President Ulysses Grant to acquire Santo Domingo.[38]

Canada could never be defended so the British decided to cut their losses and eliminate the risk of a conflict with the U.S. The first ministry of William Gladstone withdrew from all its historic military and political responsibilities in North America. It brought home its troops (keeping Halifax as an Atlantic naval base), and turned responsibility over to the locals. That made it wise to unify the separate Canadian colonies into a self-governing confederation named the Dominion of Canada.[39]

James G. Blaine, a leading Republican (and its losing candidate for president in 1884) was a highly innovative Secretary of State in the 1880s. By 1881, Blaine had completely abandoned his high-tariff Protectionism and used his position as Secretary of State to promote freer trade, especially within the Western Hemisphere.[40] His reasons were twofold: firstly, Blaine's wariness of British interference in the Americas was undiminished, and he saw increased trade with Latin America as the best way to keep Britain from dominating the region. Secondly, he believed that by encouraging exports, he could increase American prosperity. President Garfield agreed with his Secretary of State's vision and Blaine called for a Pan-American conference in 1882 to mediate disputes among the Latin American nations and to serve as a forum for talks on increasing trade. At the same time, Blaine hoped to negotiate a peace in the War of the Pacific then being fought by Bolivia, Chile, and Peru. Blaine sought to expand American influence in other areas, calling for renegotiation of the Clayton–Bulwer Treaty to allow the United States to construct a canal through Panama without British involvement, as well as attempting to reduce British involvement in the strategically located Kingdom of Hawaii.[41] His plans for the United States' involvement in the world stretched even beyond the Western Hemisphere, as he sought commercial treaties with Korea and Madagascar. By 1882, however, a new Secretary was reversing Blaine's Latin American initiatives.[42]

Serving again as Secretary of State under Benjamin Harrison, Blaine worked for closer ties with the Kingdom of Hawaii, and sponsored a program to bring together all the independent nations of the Western Hemisphere in what became the Pan-American Union.[43]

Before 1892 senior diplomats from the United States to other countries, and from them to the U.S., were called "ministers." In 1892 four major European countries (Britain, France, Germany Italy) raise title of their chief diplomat to the US to "ambassador"; the US reciprocated in 1893.[44]

While European powers, and Japan, engaged in an intense scramble for colonial possessions in Africa and Asia, the United States stood aloof. This began to change in 1893. By the early 1880s, the United States had a small army stationed at scattered Western forts, and an old fashioned wooden navy. By 1890 the U.S. began investment in new naval technology including steam-powered battleships with powerful armaments and steel decking.

In 1893 the business community in Kingdom of Hawaii overthrew the Queen and sought annexation by President Harrison, who forwarded the proposal to the Senate for approval. But the newly elected President Cleveland withdrew the proposed annexation; Hawaii formed an independent Republic of Hawaii. Unexpectedly foreign-policy became a central concern of American politics. Historian Henry Graff says that at first, "Public opinion at home seemed to indicate acquiescence...."Unmistakably, the sentiment at home was maturing with immense force for the United States to join the great powers of the world in a quest for overseas colonies."[45]

President Grover Cleveland, on taking office in March 1893, rescinded the annexation proposal. His biographer Alyn Brodsky argues he was deeply adverse to an immoral action against the little kingdom :

Just as he stood up for the Samoan Islands against Germany because he opposed the conquest of a lesser state by a greater one, so did he stand up for the Hawaiian Islands against his own nation. He could have let the annexation of Hawaii move inexorably to its inevitable culmination. But he opted for confrontation, which he hated, as it was to him the only way a weak and defenseless people might retain their independence. It was not the idea of annexation that Grover Cleveland opposed, but the idea of annexation as a pretext for illicit territorial acquisition.[46]

Cleveland had to mobilize support from Southern Democrats to fight the treaty. He sent former Georgia Congressman James H. Blount as a special representative to Hawaii to investigate and provide a solution. Blount was well known for his opposition to imperialism. Blount was also a leader in the white supremacy movement that in the 1890s was ending the right to vote by southern Blacks.. Some observers speculated he would support annexation on grounds of the inability of the Asiatics to govern themselves. Instead, Blount opposed imperialism, and called for the US military to restore of Queen Liliuokalani. He argued that the Hawaii natives should be allowed to continue their "Asiatic ways."[47]

A vigorous nationwide anti-expansionist movement, organized as the American Anti-Imperialist League, emerged that listened to Cleveland and Carl Schurz, as well as Democratic leader William Jennings Bryan, industrialist Andrew Carnegie, author Mark Twain and sociologist William Graham Sumner, and many prominent intellectuals and politicians who came of age in the Civil War.[50] The anti-imperialists opposed expansion, believing that imperialism violated the fundamental principle that just republican government must derive from "consent of the governed." The League argued that such activity would necessitate the abandonment of American ideals of self-government and non-intervention—ideals expressed in the Declaration of Independence, George Washington's Farewell Address and Lincoln's Gettysburg Address.[51]

Despite the efforts of the Cleveland and others, Secretary of State John Hay, naval strategist Alfred T. Mahan, Republican congressman Henry Cabot Lodge, Secretary of War Elihu Root, and young politician Theodore Roosevelt rallied expansionists. They had vigorous support from newspaper publishers William Randolph Hearst and Joseph Pulitzer, whipping up popular excitement. Mahan and Roosevelt designed a global strategy calling for a competitive modern navy, Pacific bases, an isthmian canal through Nicaragua or Panama, and, above all, an assertive role for America as the largest industrial power.[52] President McKinley's position was that Hawaii could never survive on its own. It would quickly be gobbled up by Japan—already a fourth of the islands' population was Japanese. Japan would then dominate the Pacific and undermine American hopes for large-scale trade with Asia.[53] While the Democrats could block a treaty in the Senate by denying it a two thirds majority, McKinley annexed Hawaii through a joint resolution, which required only a majority vote in each house. Hawaii became a territory in 1898 with full U.S. citizenship for its residents. It became the 50th state in 1959.[54]

Uncle Sam ( United States) rejects force and violence and ask "fair field and no favor"--that is, equal opportunity for all trading nations to peacefully enter the China market. This became the Open Door Policy. Editorial cartoon by William A. Rogers in Harper's Magazine November 18, 1899.

United States, with backing from Great Britain, in 1900 announced the Open Door Policy so that all nations could gain access to the China market on equal, nonviolent terms.[55]

Foreign-policy expertise in America in the 1890s was in limited supply. The State Department had a cadre of diplomats who rotated around, but the most senior positions were political patronage appointments. The holders sometimes acquired a limited expertise, but the overall pool was shallow. At the level of presidential candidate and secretary of state, the entire half-century after 1850 showed minimal expertise or interest, with the exception of William Seward in the 1860s, and James G. Blaine in the 1880s. After 1900, experience deepened in the State Department, and at the very top level, Roosevelt, Taft, Wilson, Hoover and their secretaries of state comprised a remarkable group with deep knowledge of international affairs. American elections rarely featured serious discussion of foreign-policy, with a few exceptions such as 1910, 1916, 1920 and 1940.[56]

Anytime a crisis erupted, the major newspapers and magazines commented at length on what Washington should do. The media relied primarily on a small number of foreign-policy experts based in New York City and Boston. Newspapers elsewhere copied their reports and editorials. Sometimes the regional media had a local cadre of experts who could comment on Europe, but they rarely had anyone who knew much about Latin America or Asia. Conceptually, the media experts relied on American traditions – what would Washington or Jefferson or Lincoln have done in this crisis?-- And what impact it might have on current business conditions. Social Darwinist ideas were broad, but they seldom shaped foreign-policy views. The psychic crisis that some historians discovered in the 1890s had very little impact. Travel in Europe, and close reading of British media were the chief sources for media experts.[57] Religious magazines had a cadre of returned missionaries who were helpful, and ethnic groups, especially the Irish and the Germans and the Jews had their own national experts whose views appeared in their own periodicals.[58]

Editorial cartoon intervention in Cuba. Columbia (the American people) reaches out to help oppressed Cuba in 1897 while Uncle Sam (the U.S. government) is blind to the crisis and will not use its powerful guns to help. Judge magazine, February 6, 1897.

In the mid 1890s, American public opinion denounced the Spanish repression of the Cuban independence movement as brutal and unacceptable. The U.S. increased pressure and was dissatisfied with Spanish responses. When the American battleship the USS Maine exploded for undetermined reasons in the harbor of Havana, Cuba, on 15 February 1898, the issue became overwhelming and McKinley could not resist the demands for immediate action. Most Democrats and many Republicans demanded war to liberate Cuba. Almost simultaneously the two countries declared war. (Every other country was neutral.) The U.S. easily won the one-sided four-month-long Spanish–American War from April through July. In the Treaty of Paris, the U.S. took over the last remnants of the Spanish Empire, notably Cuba, Puerto Rico, the Philippines and Guam. It marked America's transition from a regional to a global power. Cuba was given independence under American supervision.[59] However the permanent status of the Philippines became a heated political topic. Democrats, led by William Jennings Bryan, had strongly supported the war but not strongly opposed annexation.[60] McKinley was reelected and annexation was decided.[61]

The U.S. Navy emerged as a major naval power thanks to modernization programs begun in the 1880s and adopted the sea power theories of Captain Alfred Thayer Mahan. The Army remained small but was reorganized in the Roosevelt Administration along modern lines and no longer focused on scattered forts in the West. The Philippine–American War was a short operation to suppress insurgents and ensure U.S. control of the islands; by 1907, however, interest in the Philippines as an entry to Asia faded in favor of the Panama Canal, and American foreign policy centered on the Caribbean. The 1904 Roosevelt Corollary to the Monroe Doctrine, which proclaimed a right for the United States to intervene to stabilize weak states in the Americas, further weakened European influence in Latin America and further established U.S. regional hegemony.[62]

The outbreak of the Mexican Revolution in 1910 ended a half century of peaceful borders and brought escalating tensions, as revolutionaries threatened American business interests and hundreds of thousands of refugees fled north. President Woodrow Wilson tried using military intervention to stabilize Mexico but that failed. After Mexico in 1917 rejected Germany's invitation in the Zimmermann Telegram to join in war against the U.S., relations stabilized and there were no more interventions in Mexico. Military interventions did occur in other small countries like Nicaragua, but were ended by the Good Neighbor policy announced by President Franklin D. Roosevelt in 1933, which allowed for American recognition of and friendship with dictatorships.[63]

American foreign policy was largely determined by President Woodrow Wilson, who had shown little interest in foreign affairs before entering the White House in 1913. His chief advisor was "Colonel" Edward House, who was sent on many top-level missions. The United States intervened militarily in many Latin American nations to protect U.S. interests, particularly the commercial interests of the American business community. President Wilson landed U.S. troops in Mexico in 1914, in Haiti in 1915, in the Dominican Republic in 1916, in Mexico a second time in 1916, and in Mexico several additional times before Wilson left office, in Cuba in 1917, and in Panama in 1918. Also, for most of the Wilson administration, the U.S. military occupied Nicaragua, installed a Nicaraguan president that the U.S. preferred, and ensured that the country signed treaties favorable to the U.S.[64]

With the outbreak of war in 1914, the United States declared neutrality and worked to broker a peace. It insisted on its neutral rights, which included allowing private corporations and banks to sell or loan money to either side. With the British blockade, there were almost no sales or loans to Germany, only to the Allies. The widely publicized atrocities in Germany shocked American public opinion. Neutrality was supported by Irish-Americans, who hated Britain, by German Americans who wanted to remain neutral, and by women and the churches. It was supported by the more educated upscale WASP element, led by Theodore Roosevelt. Wilson insisted on neutrality, denouncing both British and German violations, especially those German violations in which American civilians were killed. The German U-boat torpedoed the RMS Lusitania in 1915. It sank in 20 minutes, killing 128 American civilians and over 1,000 Britons. It was against the laws of war to sink any passenger ship without allowing the passengers to reach the life boats. American opinion turned strongly against Germany as a bloodthirsty threat to civilization.[65] Germany apologized and repeatedly promised to stop attacks by its U-boats, but reversed course in early 1917 when it saw the opportunity to strangle Britain by unrestricted submarine warfare. It also made overtures to Mexico, in the Zimmermann Telegram, hoping to divert American military attention to south of the border. The German decision was not made or approved by the civilian government in Berlin, but by the military commanders and the Kaiser. They realized it meant war with the United States, but hoped to weaken the British by cutting off its imports, and strike a winning blow with German soldiers transferred from the Eastern front, where Russia had surrendered. Following the repeated sinking of American merchant ships in early 1917, Wilson asked Congress and obtained a declaration of war in April 1917. He neutralized the antiwar element by arguing this was a war with the main goal of ending aggressive militarism and indeed ending all wars. During the war the U.S. was not officially tied to the Allies by treaty, but military cooperation meant that the American contribution became significant in mid-1918. After the failure of the German spring offensive, as fresh American troops arrived in France at 10,000 a day, the Germans were in a hopeless position, and thus surrendered. Coupled with Wilson's Fourteen Points in January 1918, the U.S. now had the initiative on the military, diplomatic and public relations fronts. Wilsonianism—Wilson's ideals—had become the hope of the world, including the civilian population Germany itself.[66]

The U.S. military together with forces of its Allies invaded Russia in 1918. Approximately 250,000 invading soldiers, including troops from Europe, the US and the Empire of Japan invaded Russia to aid the White Army against the Red Army of the new Soviet government in the Russian civil war. The invaders launched the North Russia invasion from Arkhangelsk and the Siberia invasion from Vladivostok. The invading forces included 13,000 U.S. troops whose mission after the end of World War I included the toppling of the new Soviet government and the restoration of the previous Tsarist regime. U.S. and other Western forces were unsuccessful in this aim and withdrew by 1920 but the Japanese military continued to occupy parts of Siberia until 1922 and the northern half of Sakhalin until 1925.[67]

Historian Robert Maddox summarised, "The immediate effect of the intervention was to prolong a bloody civil war, thereby costing thousands of additional lives and wreaking enormous destruction on an already battered society."[68] According to historian Frederick L. Schuman, the long term consequences of the expedition "were to poison East-West relations forever after, to contribute significantly to the origins of World War II and the later 'Cold War,' and to fix patterns of suspicion and hatred on both sides which even today threaten worse catastrophes in time to come."[69] For Soviet leaders, the operation was proof that Western powers were keen to destroy the Soviet government if they had the opportunity to do so.[70]

British prime minister Lloyd George, Italy's Vittorio Emanuele Orlando, France's Georges Clemenceau, and Wilson at the Treaty of Versailles in 1919.

At the peace conference at Versailles, Wilson tried with mixed success to enact his Fourteen Points. He was forced to accept British, French and Italian demands for financial revenge: Germany would be made to pay reparations that amounted to the total cost of the war for the Allies and admit guilt in humiliating fashion. It was a humiliating punishment for Germany which subsequent commentators thought was too harsh and unfair. Wilson succeeded in obtaining his main goal, a League of Nations that would hopefully resolve all future conflicts before they caused another major war.[71] Wilson, however, refused to consult with Republicans, who took control of Congress after the 1918 elections and which demanded revisions protecting the right of Congress to declare war. Wilson refused to compromise with the majority party in Congress, or even bring any leading Republican to the peace conference. His personal enemy, Henry Cabot Lodge, now control the Senate. Lodge did support the league of Nations, but wanted provisions that would insist that only Congress could declare war on behalf of the United States. Wilson was largely successful in designing the new League of Nations, declaring it would be:

a great charter for a new order of affairs. There is ground here for deep satisfaction, universal reassurance, and confident hope.[72]

The League did go into operation, but the United States never joined. With a two-thirds vote needed, the Senate did not ratify either the original Treaty or its Republican version. Washington made separate peace treaties with the different European nations. Nevertheless, Wilson's idealism and call for self-determination of all nations had an effect on nationalism across the globe, while at home his idealistic vision, called "Wilsonianism" of spreading democracy and peace under American auspices had a profound influence on much of American foreign policy ever since.[73]

Perhaps the harshest attack on Wilson's diplomacy comes from Stanford historian Thomas A. Bailey in two books that remain heavily cited by scholars, Woodrow Wilson and the Lost Peace (1944) and Woodrow Wilson and the Great Betrayal (1945), Bailey:

contended that Wilson's wartime isolationism, as well as his peace proposals at war's end, were seriously flawed. Highlighting the fact that American delegates encountered staunch opposition to Wilson's proposed League of Nations, Bailey concluded that the president and his diplomatic staff essentially sold out, compromising important American ideals to secure mere fragments of Wilson's progressive vision. Hence, while Bailey primarily targeted President Wilson in these critiques, others, including House, did not emerge unscathed.[74]

Scot Bruce argues that:

More recently, prominent historians such as Thomas J. Knock, Arthur Walworth, and John Milton Cooper, among others, shied away from condemning Wilson and his peacemakers for extensive diplomatic failures in Paris. Instead, they framed Wilsonian progressivism, articulated through the League of Nations, as a comparatively enlightened framework tragically undermined by British and French machinations at the peace conference. ... Historian Margaret MacMillan, continued this analytical trend in her prize-winning book, Paris, 1919: Six Months That Changed the World (2001), which characterized Wilson as the frustrated idealist, unable to secure his progressive vision due to opposition from old-guard imperialists in his midst. While realists like Lloyd E. Ambrosius questioned the merits of defining Wilsonian progressivism too idealistically, the idea has persisted that well-intentioned U.S. delegates encountered staunch opposition to Wilson's proposals in Paris, and therefore compromised under pressure. Even the great Wilson scholar, Arthur S. Link, subscribed to a version of this narrative.[75]

In the 1920s, American policy was an active involvement in international affairs, while ignoring the League of Nations, setting up numerous diplomatic ventures, and using the enormous financial power of the United States to dictate major diplomatic questions in Europe. There were large-scale humanitarian food aid missions during the war in Belgium, and after it in Germany and Russia, led by Herbert C. Hoover.[76] There was also a major aid to Japan after the 1923 earthquake.[77]

The Republican presidents, Warren Harding, Calvin Coolidge and Herbert Hoover, avoided any political alliances with anyone else. They operated large-scale American intervention in issues of reparations and disarmament, with little contact with the League of Nations. Historian Jerald Combs reports their administrations in no way returned to 19th-century isolationism. The key Republican leaders:

including Elihu Root, Charles Evans Hughes, and Hoover himself, were Progressives who accepted much of Wilson's internationalism.... They did seek to use American political influence and economic power to goad European governments to moderate the Versailles peace terms, induce the Europeans to settle their quarrels peacefully, secure disarmament agreements, and strengthen the European capitalist economies to provide prosperity for them and their American trading partners.[78]

The U.S, played a major role in setting up the "Permanent Court of International Justice", known as the World Court.[79] Presidents Wilson, Harding, Coolidge, and Hoover supported membership but were unable to get a 2/3 majority in the Senate for a treaty. Roosevelt also supported membership, but he did not make it a high priority. Opposition was intense on the issue of losing sovereignty, led by the Hearst newspapers and Father Coughlin. The U.S. never joined.[80][81][82] The World Court was replaced by the International Court of Justice in 1945. However The Connally Amendment of 1944 reserved the right of the United States to refuse to abide by its decisions. Margaret A. Rague, argues this reduced the strength of the Court, discredited America's image as a proponent of international law, and exemplified the problems created by vesting a reservation power in the Senate.[83][84]

Secretary of State Charles Evans Hughes served as chairman of the Washington Naval Conference

The Washington Naval Conference, was the most successful diplomatic venture the 1920s. It was held in Washington, under the Chairmanship of Secretary of State Charles Evans Hughes from 12 November 1921 to 6 February 1922. Conducted outside the auspice of the League of Nations, it was attended by nine nations—the United States, Japan, China, France, Great Britain, Italy, Belgium, Netherlands, and Portugal[85] Soviet Russia was not invited to the conference. It focused on resolving misunderstandings or conflicts regarding interests in the Pacific Ocean and East Asia. The main achievement was a series of naval disarmament agreements agreed to by all the participants, that lasted for a decade. It resulted in three major treaties: Four-Power Treaty, Five-Power Treaty (the Washington Naval Treaty), the Nine-Power Treaty, and a number of smaller agreements. These treaties preserved peace during the 1920s but Were not renewed, as the world scene turned increasingly negative after 1930.[86]

The Dawes plan was the American solution to the crisis of reparations, in which France was demanding more money than Germany was willing to pay, so France occupied the key industrial Ruhr district of Germany with its army. The Occupation of the Ruhr in 1923 Caused an international crisis; Germany deliberately hyperinflated currency, making the occupation highly expensive for France. The crisis was solved by a compromise brokered by the United States in the form of the Dawes Plan in 1924.[87] This plan, sponsored by American Charles G. Dawes, set out a new financial scheme. New York banks loaned Germany hundreds of millions of dollars that it used to pay reparations and rebuild its heavy industry. France, Britain and the other countries used the reparations in turn to repay wartime loans they received from the United States. By 1928 Germany called for a new payment plan, resulting in the Young Plan that established the German reparation requirements at 112 billion marks (US$26.3 billion ) and created a schedule of payments that would see Germany complete payments by 1988. With the collapse of the German economy in 1931, reparations were suspended for a year and in 1932 during the Lausanne Conference they were suspended indefinitely. Between 1919 and 1932, Germany paid less than 21 billion marks in reparations. After 1953 West Germany paid the entire remaining balance.[88]

Since the turmoil of the Mexican revolution had died down, the Harding administration was prepared to normalize relations with Mexico. Between 1911 and 1920 American imports from Mexico increased from $57,000,000 to $179,000,000 and exports from $61,000,000 to $208,000,000. Commerce Secretary Herbert Hoover took the lead in order to promote trade and investments other than in oil and land, which had long dominated bilateral economic ties. President Álvaro Obregón assured Americans that they would be protected in Mexico, and Mexico was granted recognition in 1923.[89] A major crisis erupted in the mid-1930s when the Mexican government expropriated millions of acres of land from hundreds of American property owners as part of President Lázaro Cárdenas's land redistribution program. No compensation was provided to the American owners.[90] The emerging threat of the Second World War forced the United States to agree to a compromise solution. The US negotiated an agreement with President Manuel Avila Camacho that amounted to a military alliance.[91]

Small-scale military interventions continued after 1921 as the Banana Wars tapered off. The Hoover administration began a goodwill policy and withdrew all military forces.[92] President Roosevelt announced the "Good Neighbor Policy" by which the United States would no longer intervene to promote good government, but would accept whatever governments were locally chosen. His Secretary of State Cordell Hull endorsed article 8 of the 1933 Montevideo Convention on Rights and Duties of States; it provides that "no state has the right to intervene in the internal or external affairs of another".[93]

In the 1930s, the United States entered the period of deep isolationism, rejecting international conferences, and focusing mostly on reciprocal tariff agreements with smaller countries of Latin America.

When the Spanish Civil War erupted in 1936, the United States remained neutral and banned arms sales to either side. This was in line with both American neutrality policies, and with a Europe-wide agreement to not sell arms for use in the Spanish war lest it escalate into a world war. Congress endorsed the embargo by a near-unanimous vote. Only armaments were embargoed; American companies could sell oil and supplies to both sides of the fight. Roosevelt quietly favored the left-wing Republican (or "Loyalist") government, but intense pressure by American Catholics forced him to maintain a policy of neutrality. The Catholics were outraged by the systematic torture, rape and execution of priests, bishops, and nuns by anarchist elements of the Loyalist coalition. This successful pressure on Roosevelt was one of the handful of foreign policy successes notched by Catholic pressures on the White House in the 20th century.[94]

Germany and Italy provided munitions, and air support, and troops to the Nationalists, led by Francisco Franco. The Soviet Union provided aid to the Loyalist government, and mobilized thousands of volunteers to fight, including several hundred from the United States in the Abraham Lincoln Battalion. All along the Spanish military forces supported the nationalists, and they steadily pushed the government forces back. By 1938, however, Roosevelt was planning to secretly send American warplanes through France to the desperate Loyalists. His senior diplomats warned that this would worsen the European crisis, so Roosevelt desisted.[95]

Adolf Hitler and Franco mutually disliked one another, and Franco repeatedly manipulated Hitler for his own benefit during World War Two. Franco sheltered Jewish refugees escaping through France and never turned over the Spanish Jews to Nazi Germany as requested, and when during the Second World War the Blue Division was dispatched to help the Germans, it was forbidden to fight against the Allies, and was limited only to fighting the Soviet.[96]

President Roosevelt tried to avoid repeating what he saw as Woodrow Wilson's mistakes in World War I.[97] He often made exactly the opposite decision. Wilson called for neutrality in thought and deed, while Roosevelt made it clear his administration strongly favored Britain and China. Unlike the loans in World War I, the United States made large-scale grants of military and economic aid to the Allies through Lend-Lease, with little expectation of repayment. Wilson did not greatly expand war production before the declaration of war; Roosevelt did. Wilson waited for the declaration to begin a draft; Roosevelt started one in 1940. Wilson never made the United States an official ally but Roosevelt did. Wilson never met with the top Allied leaders but Roosevelt did. Wilson proclaimed independent policy, as seen in the 14 Points, while Roosevelt always had a collaborative policy with the Allies. In 1917, the United States declared war on Germany; in 1941, Roosevelt waited until the enemy attacked at Pearl Harbor. Wilson refused to collaborate with the Republicans; Roosevelt named leading Republicans to head the War Department and the Navy Department. Wilson let General John J. Pershing make the major military decisions; Roosevelt made the major decisions in his war including the "Europe first" strategy. He rejected the idea of an armistice and demanded unconditional surrender. Roosevelt often mentioned his role in the Wilson administration, but added that he had profited more from Wilson's errors than from his successes.[98][99][100]

Political scientist Roberta Wohlstetter explores why all American intelligence agencies failed to predict the attack on Pearl Harbor. The basic reason was that the Japanese plans were a very closely held secret. The attack fleet kept radio silence and was not spotted by anyone en route to Hawaii. There were air patrols over Hawaii, but they were too few and too ineffective to scan a vast ocean. Japan Navy spread false information—using fake radio signals—to indicate the main fleet was in Japanese waters, and suggested their main threat was north toward Russia. The U.S. had MAGIC, which successfully cracked the Japanese diplomatic code. However, the Japanese Foreign Ministry and its diplomats were deliberately never told about the upcoming attack, so American intelligence was wasting its time trying to discover secrets through MAGIC. American intelligence expected attacks against British and Dutch possessions, and were looking for those clues. At Pearl Harbor, they focused on predicting local sabotage. There was no overall American intelligence center until the formation in 1942 of the Office of Strategic Services. It was the forerunner of the Central Intelligence Agency (CIA). In 1941 there was no coordination of the information coming in from the Army, Navy, and State department as well as from the British and Dutch allies. The system of notification was also flawed, and what the sender thought was an urgent message did not appear urgent to the recipient. After the attack, congressional investigators identified and linked together all sorts of small little signals pointing to an attack, while they discarded signals pointing in other directions. Even in hindsight there was so much confusion, noise, and poor coordination that Wohlstetter concludes no accurate predictions of the attack on Pearl Harbor was at all likely before December 7.[101][102]

The same pattern which emerged with the first world war continued with the second: warring European powers, blockades, official U.S. neutrality but this time President Roosevelt tried to avoid all of Wilson's mistakes. American policy substantially favored Britain and its allies, and the U.S. getting caught up in the war. Unlike the loans in World War I, the United States made large-scale grants of military and economic aid to the Allies through Lend-Lease. Industries greatly expanded to produce war materials. The United States officially entered World War II against Germany, Japan, and Italy in December 1941, following the Japanese surprise attack on Pearl Harbor. This time the U.S. was a full-fledged member of the Allies of World War II, not just an "associate" as in the first war. During the war, the U.S. conducted military operations on both the Atlantic and Pacific fronts. After the war and devastation of its European and Asian rivals, the United States found itself in a uniquely powerful position due to its enormous economic and military power .[103]

The major diplomatic decisions, especially relations with Britain, the Soviet Union, France and China, were handled in the White House by President Roosevelt and his top aide Harry Hopkins.[104][105] Secretary of State Cordell Hull handled minor routine affairs.[106] The one State Department official Roosevelt depended upon was strategist Sumner Welles, whom Hull drove out of office in 1943.[107]

The major long-term goal of Roosevelt's foreign policy during the war was creating a United Nations to resolve all world problems

After 1945, the isolationist pattern that characterized the inter-war period had ended for good. Roosevelt policy supported a new international organization that would be much more effective than the old League of Nations, and avoid its flaws. He successfully sponsored the formation of the United Nations.

The United States was a major force in establishing the United Nations in 1945, hosting a meeting of fifty nations in San Francisco. Avoiding the rancorous debates of 1919, where there was no veto, the US and the Soviet Union, as well as Britain, France and China, became permanent members of the Security Council with veto power. The idea of the U.N. was to promote world peace through consensus among nations, with boycotts, sanctions and even military power exercised by the Security Council. It depended on member governments for funds and had difficulty funding its budget. In 2009, its $5 billion budget was funded using a complex formula based on GDP; the U.S. contributed 20% in 2009. However, the United Nations' vision of peace soon became jeopardized as the international structure was rebalanced with the development and testing of nuclear weapons by major powers.

From the late 1940s until 1991, world affairs were dominated by the Cold War, in which the U.S. and its allies faced the Soviet Union and its allies. There was no large-scale fighting but instead numerous regional wars as well as the ever-present threat of a catastrophic nuclear war.[108][109]

In 1948 the United States enacted the Marshall Plan, which supplied Western Europe—including Germany—with US$13 billion in reconstruction aid. Stalin vetoed any participation by East European nations. A similar program was operated by the United States to restore the Japanese economy. The U.S. actively sought allies, which it subsidized with military and economic "foreign aid", as well as diplomatic support. The main diplomatic initiative was the establishment of the North Atlantic Treaty Organization (NATO) in 1949, committing the United States to nuclear defense of Western Europe, which engaged in a military buildup under NATO's supervision. The result was peace in Europe, coupled with the fear of Soviet invasion and a reliance on American protection.[110] In the 1950s, a number of other less successful regional alliances were developed by the United States, such as the Southeast Asia Treaty Organization (SEATO). Economic and propaganda warfare against the communist world was part of the American toolbox.[111] The United States operated a worldwide network of bases for its Army, Navy and Air Force, with large contingents stationed in Germany, Japan and South Korea.[112]

Most nations aligned with either the Western or Eastern camp, but after 1960 the Soviets broke with China as the Communist movement worldwide became divided. Some countries, such as India and Yugoslavia, tried to be neutral. Rejecting the rollback of Communism by force because it risked nuclear war, Washington developed a new strategy called containment to oppose the spread of communism. The containment policy was developed by U.S. diplomat George Kennan in 1947. Kennan characterized the Soviet Union as an aggressive, anti-Western power that necessitated containment, a characterization which would shape US foreign policy for decades to come. The idea of containment was to match Soviet aggression with force wherever it occurred while not using nuclear weapons. The policy of containment created a bipolar, zero-sum world where the ideological conflicts between the Soviet Union and the United States dominated geopolitics. Due to the antagonism on both sides and each countries' search for security, a tense worldwide contest developed between the two states as the two nations' governments vied for global supremacy militarily, culturally, and influentially.

The Cold War was characterized by a lack of global wars but a persistence of regional proxy wars, often fought between client states and proxies of the United States and Soviet Union. The US also intervened in the affairs of other countries through a number of secret operations.

During the Cold War, the Containment policy seeking to stop Soviet expansion, involved the United States and its allies in the Korean War (1950–1953), a stalemate. Even longer and more disastrous was the Vietnam War (1963–75). Under Jimmy Carter, the U.S. and its Arab allies Succeeded in creating a Vietnamese -like disaster for the Soviet Union by supporting anti-Soviet Mujahideen forces in Afghanistan (Operation Cyclone).[113]

President Kennedy meeting with Soviet foreign minister Gromyko in 1962. Kennedy knew about Soviet missiles in Cuba but had not revealed this information yet. The Cuban Missile crisis brought the world close to the brink of World War III but luckily cooler heads prevailed.

The Cold War reached its most dangerous point during the Kennedy administration in the Cuban Missile Crisis, a tense confrontation between the Soviet Union and the United States over the Soviet deployment of nuclear missiles in Cuba. The crisis began on October 16, 1962, and lasted for thirteen days. It was the moment when the Cold War was closest to exploding into a devastating nuclear exchange between the two superpower nations. Kennedy decided not to invade or bomb Cuba but to institute a naval blockade of the island. The crisis ended in a compromise, with the Soviets removing their missiles publicly, and the United States secretly removing its nuclear missiles in Turkey. In Moscow, Communist leaders removed Nikita Khrushchev because of his reckless behavior.[114]

Vietnam and the Cold War are the two major issues that faced the Kennedy presidency. Historians disagree. However, there is general scholarly agreement that his presidency was successful on a number of lesser issues. Thomas Paterson finds that the Kennedy administration helped quiet the crisis over Laos; was suitably cautious about the Congo; liberalized trade; took the lead in humanitarianism especially with the Peace Corps; helped solve a nasty dispute between Indonesia and the Netherlands; achieve the Limited Test Man Treaty; created a new Arms Control and Disarmament Agency; defended Berlin; and strengthened European defenses. His willingness to negotiate with Khrushchev smoothed the Berlin crisis, and Kennedy's personal diplomacy earned him the respect of Third World leaders.[115]

On the two major issues, no consensus has been reached. Michael L. Krenn argues in 2017:

Fifty-some years after his assassination, John F. Kennedy remains an enigma. Was he the brash and impulsive president who brought the world to the brink of World War III with the Cuban Missile Crisis? Or was he the brave challenger of the American military-industrial complex who would have prevented the Vietnam War? Various studies portray him as a Cold War liberal, or a liberal Cold Warrior, or come up with pithy phrases to summarize the man and his foreign policy.[116]

The Containment policy meant fighting communist expansion where ever it occurred, and the Communists aimed where the American allies were weakest. When he became president in November 1963, Lyndon Johnson's primary commitment was to his domestic policy, so he tried to minimize public awareness and congressional oversight of the operations in the war.[117] Most of his advisers were pessimistic about the long term possibilities, and Johnson feared that if Congress took control, it would demand "Why Not Victory", as Barry Goldwater put it, rather than containment.[118] American Boots on the ground in Vietnam skyrocketed from 16,000 soldiers in 1963 to over 500,000 in 1968, plus many others in support roles outside Vietnam. Johnson refused to allow the trained men of the Army reserves or the National Guard to serve in Vietnam, because that would involve Congressional oversight. Instead he relied increasingly on the draft, which became increasingly unpopular. With college deferments from the draft widely available, out of the 2.5 million Americans who served in Vietnam (out of 27 million Americans eligible to serve in the military) 80% came from poor and working-class backgrounds.[119] In August 1964 Johnson secured almost unanimous support in Congress for the Gulf of Tonkin Resolution, which gave him very broad discretion to use military force as he saw fit. South Vietnam had a large Well-equipped army, but it left nearly all the fighting to the Americans. In February 1968 the Viet Cong launched an all-out attack on South Vietnamese forces across the country in the Tet Offensive. The ARVN (South Vietnam's army) successfully fought off the attacks and reduced the Viet Cong to a state of ineffectiveness; thereafter, it was the army of North Vietnam that was the main opponent.[120] However the Tet Offensive proved a public relations disaster for Johnson, as the public increasingly realized the United States was deeply involved in a war that few people understood.

Civilians shot by American soldiers in the My Lai massacre.

Starting in 1964, the antiwar movement began. Some opposed the war on moral grounds, rooting for the peasant Vietnamese against the modernizing capitalistic Americans. Opposition was centered among the black activists of the civil rights movement, and college students at elite universities.[121] Republicans, such as California Governor Ronald Reagan, demanded victory or withdrawal, while on the left strident demands for immediate withdrawal escalated.[122]

President Richard Nixon (1969–74) radically transformed American policy, with the aid of his top advisor Henry Kissinger.[123] First of all he rejected the long-standing containment policy that made it the highest goal to stop the expansion of communism. By playing off the two main communist rivals, China and the USSR, he managed to put a pause on the Cold War through friendly relationships with each of them, or Détente. Moscow and Beijing went along, and accepted Nixon's terms of pulling their support away from Vietnam. This allowed Nixon to turn that war over to the government of South Vietnam, withdrawing all American and Allied troops, while continuing a bombing threat. The Vietnamization policy seem to work until 1975, when North Vietnam militarily conquered South Vietnam as the United States stood by without intervening.[124] After Nixon resigned, president Gerald Ford continued his foreign policy, but came under strong attack from the right by Ronald Reagan, whom he defeated for the nomination in 1976.[125]

The Nixon Doctrine announced in July 1969 shifted the main responsibility for the defense of an ally, to the ally itself, especially regarding combat. The United States would work on the diplomacy, provide financial help and munitions, and help train the allied army. Specifically:

• The U.S. would keep all its treaty commitments.
• The U.S. would “provide a shield if a nuclear power threatens the freedom of a nation allied with us or of a nation whose survival we consider vital to our security.”
• In conflicts involving non-nuclear aggression, the U.S. would “look to the nation directly threatened to assume the primary responsibility of providing the manpower for defense.”[126]

The Doctrine was exemplified by the Vietnamization process regarding South Vietnam and the Vietnam War.[127] It also played elsewhere in Asia including Iran,[128] Taiwan,[129] Cambodia[130] and South Korea.[131] The doctrine was an explicit rejection of the practice that sent 500,000 American soldiers to Vietnam, even though there was no treaty obligation to that country. A major long-term goal was to reduce the tension between the United States and the Soviet Union and China, so as to better enable the détente process to work.[132] The particular Asian nation the Nixon Doctrine was aimed at with its message that Asian nations should be responsible for defending themselves was South Vietnam, but Shah Mohammad Reza Pahlavi of Iran seized upon the Nixon Doctrine with its message that Asian nations should be responsible for their own defense to argue that the Americans should sell him arms without limitations, a suggestion that Nixon eagerly embraced.[133] The US turned to Saudi Arabia and Iran as "twin pillars" of regional stability.[134] Oil price increases in 1970 and 1971 would allow funding both states with this military expansion. Total arms transfers from the United States to Iran increased from $103.6 million in 1970 to $552.7 million in 1972; those to Saudi Arabia increased from $15.8 million in 1970 to $312.4 million in 1972. The United States would maintain its small naval force of three ships in the Gulf, stationed since World War II in Bahrain, but would take on no other formal security commitments.[135]

A war for independence broke out in East Pakistan in 1971 with India joining in to defeat Pakistan, an American ally. Nixon sent a carrier group to the Bay of Bengal to symbolize support for Pakistan but without any combat action. Nixon and Kissinger saw India's alliance with the USSR as a threat to American interests. However they realized the American public would not accept hostilities against a fellow democracy.[136] Pakistan was a critical ally in the secret negotiations underway for a rapprochement with China. Nixon feared that an Indian invasion of West Pakistan would risk Soviet domination of the region, and that it would seriously undermine the global position of the United States and the regional position of America's new tacit ally, China. To demonstrate to China the bona fides of the United States as an ally, and in direct defiance of the US Congress-imposed sanctions on Pakistan, Nixon sent military supplies to Pakistan, while also encouraging China to increase its arms supplies to Pakistan. In the end Pakistan lost and Bangladesh became independent, but the USSR did not expand its control. India resented the American role for decades.[137]

Democrat Jimmy Carter defeated Ford in the election of 1976, but his foreign-policy became mired in endless difficulties, including a proxy war against the Soviet Union in Afghanistan, and a confrontation with the new anti-American regime in Iran.[138][139] Carter had very little foreign policy experience, and he was unable to stop the bitter infighting between his top foreign policy advisers, Secretary of State Cyrus Vance, on the dovish size, versus national security adviser Zbigniew Brzezinski The Advisor was a hard line Cold Warrior opposed to Communism and the USSR. Carter initially wanted to nominate George Ball as Secretary of State, but he was vetoed by Brzezinski as too dovish.[140] Vance negotiated the Panama Canal Treaties, along with peace talks in Rhodesia, Namibia and South Africa. He worked closely with Israeli Ministers Moshe Dayan and Ezer Weizman to secure the Camp David Accords in 1978. Vance was a strong advocate of disarmament. He insisted that the President make Paul Warnke Director of the Arms Control and Disarmament Agency, over strong opposition by Senator Henry M. Jackson. The firecest debates came over continuing détente policies with Moscow. Vance tried to advance arms limitations by working on the SALT II agreement with the Soviet Union, which he saw as the central diplomatic issue of the time, but Brzezinski lobbied for a tougher more assertive policy vis-a-vis the Soviets. He argued for strong condemnation of Soviet activity in Africa and in the Third World as well as successfully lobbying for normalized relations with the People's Republic of China in 1978. Brzezinski took control of the negotiations with Beijing. Vance was marginalized and his influence began to wane. When revolution erupted in Iran in late 1978, the two were divided on how to support the long-time ally the Shah of Iran. Vance argued in favor of demanding reforms while Brzezinski urged the Shah to crack down. Unable to obtain a direct course of action from Carter, the mixed messages that the Shah received from Vance and Brzezinski contributed to his confusion and indecision as he fled Iran in January 1979 and his regime collapsed.[141] In April 1980, Vance resigned in protest because of the failed Operation Eagle Claw, the secret mission to rescue American hostages in Iran which he had opposed. He was succeeded by Edmund Muskie.[142]

Reagan rejected détente, and containment, and announced his goal was to win the Cold War, by destroying the threat of Soviet communism, denouncing Moscow as the "evil Empire". His main action was a dramatic increase in military spending, and a heavy investment in high-tech weapons that the Soviets, with their primitive computer systems, were unable to match.[143][144] After furious political battles at home and in Western Europe, Reagan succeeded in stationing medium-range ballistic Missiles in Western Europe, aimed at the Soviet Union.[145]

The Reagan administration made dramatic increases in defense spending one of their three main priorities on taking office, along with cutting taxes and welfare. The transition to the new professional all-professional force was finalized, and the draft forgotten. A dramatic expansion of salary bases and benefits for both enlisted and officers made career service much more attractive. Under the aggressive leadership of Defense Secretary Caspar Weinberger, the development of the B-1 bomber was reinstated, and there was funding for a new B-2 bomber, as well as cruise missiles, the MX missile, and a 600 ship Navy. The new weaponry was designed with Soviet targets in mind. In terms of real dollars after taxation, defense spending jump 34 percent between 1981 in 1985. Reagan's two terms, defense spending totaled about 2 trillion dollars, but even so it was a lower percentage of the federal budget or have the GDP, then before 1976.[146]

There were also major arms sales to build up allies as well. The most notable came in 1981, a $8.5 billion sale to Saudi Arabia involving aircraft, tanks, and Airborne Warning and Control Systems (AWACS). Israel protested, since the AWACS would undermine its strategic attack capabilities. To mollify Israel and its powerful lobby in Washington, the United States promised to supply it with an additional F-15 squadron, a $600 million loan, and permission to export Israeli-made Kfir fighting aircraft to Latin American armies.[147][148]

In its first term administration looked at arms control measures with deep suspicion. However, after the massive buildup, and the second term it looked at them with favor and achieve major arms reductions with Mikhail Gorbachev.[149] It was possible because the sclerotic Soviet leadership died out, and finally in 1985 Mikhail Gorbachev came to power with a commitment to salvage communism in the Soviet Union. He negotiated a series of compromises with Reagan, that weakened Soviet power. In 1989, all the East European satellites revolted in overthrew Moscow's control. West Germany took over East Germany. In 1991, Russia overthrew communism, and at the end of the year Gorbachev lost power and the Soviet Union was dissolved. The United States and NATO had won the Cold War, leaving the United States the world's only superpower.[150] Reagan had a vision for restoring American power, and defeating the Soviet enemy, and it all came true shortly after he left office. However, he was highly inattentive to details and let his senior staff, and sometimes his junior staff, make the presidential-level decisions. Putting all together, historians and presidential scholars have Reagan high marks in foreign policy. In 2017 a C-SPAN survey of scholars – most of whom opposed his specific policies—ranked Reagan in terms of leadership in comparison with all 42 presidents. He ranked number nine in international relations.[151][152]

Unlike Reagan, Bush downplayed vision and emphasized caution and careful management. His main foreign policy advisors were Secretaries of State James Baker and Lawrence Eagleburger, and National Security Advisor Brent Scowcroft. Bush entered the White House with a long and successful portfolio in foreign affairs including ambassadorial roles to China in the United Nations, director of the CIA, and official visits to 65 foreign countries as vice president. Momentous geopolitical events that occurred during Bush's presidency include:

Momentous geopolitical events that occurred during Bush's presidency include:[153][154][155]

• The crushing in June 1989 of the Tiananmen Square protests in China, which was widely condemned in the United States and around the world.
• The United States invasion of Panama in December 1989 to overthrow a local dictator.
• The signing with the USSR of the START I and START II treaties for nuclear disarmament.
• The Gulf War in 1991, in which Bush led a large coalition that defeated Iraq when it invaded Kuwait.
• Victory in the Cold War over Soviet communism.
• Revolutions of 1989 and the collapse of Communism, especially in Eastern Europe
• German reunification in 1990, with the democratic West absorbing the ex-Communist East.
• The dissolution of the Soviet Union in 1991, replaced by a friendly Russia and 14 other countries.

Except for Tiananmen Square in China, all the events strongly favored the United States. Bush took the initiative in the invasion of Panama and the START treaties. Otherwise, he was mostly a passive observer trying not to interfere or gloat about the events. Given the favorable outcomes, scholars generally give Bush high marks in foreign policy, except for his unwillingness to condemn the Tiananmen Square crackdown. He thought long-term favorable relations with China were too important to jeopardize.[156]

A decade of economic prosperity ended with the September 11, 2001 attacks on the World Trade Center in New York City. The surprise attack by terrorists belonging to a militant Al-Qaeda organization prompted a national mourning and paradigm shift in U.S. foreign policy. The focus on domestic prosperity during the 1990s gave way to a trend of unilateral action under President George W. Bush to combat what was seen to be the growing trend of fundamentalist terrorism in the Middle East. The United States declared a War on Terrorism. This policy dominated U.S. foreign policy over the last decade as the nation embarked on two military campaigns in the Middle East, in Afghanistan and Iraq. Although both campaigns attracted international support, particularly the fighting in Afghanistan, the scale and duration of the war has lessened the motivation of American allies. Furthermore, when no WMDs were found after a military conquest of Iraq, there was worldwide skepticism that the war had been fought to prevent terrorism, and the war in Iraq has had serious negative public relations consequences for the image of the United States. The "Bush Doctrine" shifted diplomatic and security policy toward maximizing the spread of liberal political institutions and democratic values. The policy has been called "democratic realism," "national security liberalism," "democratic globalism," or "messianic universalism." The policy helped inspire democratic upheavals in the Middle East.[158]

German Chancellor Angela Merkel and U.S. President George W. Bush

Across the world there was a transition from a bipolar world to a multipolar world. While the United States remains a strong power economically and militarily, rising nations such as China, India, and Brazil as well as Russia have challenged its dominance. Foreign policy analysts such as Nina Harchigian suggest that the six emerging big powers share common concerns: free trade, economic growth, prevention of terrorism, efforts to stymie nuclear proliferation. And if they can avoid war, the coming decades can be peaceful and productive provided there are no misunderstandings or dangerous rivalries.

In his first formal television interview as president, Barack Obama addressed the Muslim world through an Arabic-language satellite TV network and expressed a commitment to repair relations that have deteriorated under the previous administration.[159] Still under the Obama administration, American foreign policy has continued to irritate the Muslim world including one of its main allies, Pakistan.

But serious problems remain for the U.S. The Mideast continues to fester with religious hatred and Arab resentment of Israel. The U.S. position is that the danger of nuclear proliferation is more evident with nations such as Iran and North Korea openly flouting the international community by insisting on building nuclear weapons. Important issues such as climate change, which require many governments to work together in sometimes tough solutions, present tough diplomatic challenges.

An insight into recent thinking inside the State Department was provided in November 2010 and the following months through the WikiLeaks United States diplomatic cables release.

President Donald Trump's first Secretary of State was Rex Tillerson. a nonpolitical corporate executive who disagreed with Trump on many policy issues, and had the reputation of a very poor manager of the State Department. He was largely ignored by the White House and finally Trump fired him. Trump named Republican Congressman Mike Pompeo who took office in April 2018.[160][161]

Pompeo meeting with Crown Prince Mohammad bin Salman, The dominant figure in Saudi Arabia and a key American ally in the Middle East

Trumps foreign policy has been highly controversial. He rejected numerous agreements entered into by president Obama including the 12-nation trade deal called the "Trans-Pacific Partnership",[162] the international Paris climate accord,[163] and the Joint Comprehensive Plan of Action to curtail Iranian development of nuclear weapons.[164] He imposed tariffs on Canada, Mexico, Europe, and other nations, and opened an escalating trade war with China.. Relations with dictator Kim Jong Un of North Korea have oscillated between extreme hostility and close personal friendship. Trump has tried repeatedly to reduce entry of Muslims and Mexicans into the United States, as well as asylum-seekers from Latin America. Trump has given very strong support to Saudi Arabia and Israel, and strenuously opposed The governments of Iran and Venezuela. The business community, which generally approved his domestic tax and deregulation policies, has strongly opposed his protectionist trade policy, especially the trade war with China.[165][166]

Richard Haass argues that the Trump administration brought the reversal of many key American positions:

Support for alliances, embrace of free trade, concern over climate change, championing of democracy and human rights, American leadership per se – these and other fundamentals of American foreign policy have been questioned and, more than once, rejected.[167]

The United States was formed as the first successful revolt against a major empire in 1776, and historically has strongly imposed imperialism, as seen in the Monroe doctrine, in the war against the Spanish Empire in 1898, and support for dissolving the British and Dutch empires after 1945. Jefferson called for an empire of liberty, with the United States showing the way to Republicanism. Efforts to seize or Purchase colonies in Latin America were rejected in the 1850s. In 1898–1900 there was a fierce debate by anti-imperialists Who formed a special-purpose lobby the American Anti-Imperialist League to fight against taking control of the Philippines after Spain left the scene.[168] The chief proponents of going to war in response to the cruelty of the Spanish Empire – most notably William Jennings Bryan – insisted the United States should not follow in the same footsteps. The opponents of declaring war, led by President McKinley, decided that America had responsibilities and insisted on taking the Philippines. Congress made the decision not to take ownership of Cuba. Any excitement about becoming an imperial power was short-lived, however, and by 1905 expansionary interests under Theodore Roosevelt turned away from Asia and began focusing on the Panama Canal. The Democrats decided by 1934 to make the Philippines independent, which was done in 1946. Hawaii became integrated into the United States, and no one could decide – to this day – on the long-term status of Puerto Rico.[169]

However, during the Cold War, and especially after 9/11, critics have charged that the United States has become a worldwide empire on its own. In 1945 the United States was planning to withdraw all its forces from Europe as soon as possible, but the Soviet actions in Poland and Czechoslovakia And especially in Greece forced a rethinking. Heavily influenced by George Kennan, Washington policymakers decided that the Soviet Union was an expansionary dictatorship that threatened American interests. Moscow's weakness was that it had to keep expanding to survive, and that by containing or stopping its growth stability could be achieved in Europe. The result was the Truman Doctrine (1947) regarding Greece and Turkey. A second equally important consideration was the need to restore the world economy, which required rebuilding and reorganizing Europe for growth. This issue, more than the Soviet threat, was the main impetus behind the Marshall Plan of 1948. A third factor was the realization, especially by Britain and the three Benelux nations, that American military involvement was needed. Historians have commented on the importance of "the eagerness with which America's friendship with sought and its leadership welcomed. ... In Western Europe, America built an empire 'by invitation'-– in the striking phrase coined by Geir Lundestad."[170][171]

A leading spokesman for America-as-Empire is British historian A. G. Hopkins.[172] He argues that by the 21st century traditional economic imperialism was no longer in play, noting that the oil companies opposed the American invasion of Iraq in 2003. Instead, anxieties about The negative impact of globalization on rural and rust-belt America were at work says Hopkins:

These anxieties prepared the way for a conservative revival based on family, faith and flag that enabled the neo-conservatives to transform conservative patriotism into assertive nationalism after 9/11. In the short term, the invasion of Iraq was a manifestation of national unity. Placed in a longer perspective, it reveals a growing divergence between new globalised interests, which rely on cross-border negotiation, and insular nationalist interests, which seek to rebuild fortress America.[173]

In 2001–2010 numerous scholars debated the "America as Empire" issue.[174] Conservative Harvard professor Niall Ferguson concludes that Worldwide military and economic power have combined to make the U.S. the most powerful empire in history. It is a good idea he thinks, because like the successful British Empire in the 19th century it works to globalize free markets, enhanced the rule of law and promote representative government. He fears, however, that Americans lack the long-term commitment in manpower and money to keep the Empire operating.[175]

Many – perhaps most – scholars have decided that the United States lacks the key essentials of an empire. For example, while there are American military bases all over, the American soldiers do not rule over the local people, and the United States government does not send out governors or permanent settlers like all the historic empires did.[176] Harvard historian Charles S. Maier has examined the America-as-Empire issue at length. He says the traditional understanding of the word "empire" does not apply because the United States does not exert formal control over other nations nor engage in systematic conquest. The best term is that the United States is a "hegemon." Its enormous influence through high technology, economic power, and impact on popular culture gives it an international outreach that stands in sharp contrast to the inward direction of historic empires.[177][178]

World historian Anthony Pagden asks is the United States really an empire?

I think if we look at the history of the European empires, the answer must be no. It is often assumed that because America possesses the military capability to become an empire, any overseas interest it does have must necessarily be imperial. ... In a number of crucial respects, the United States is, indeed, very un-imperial. ... America bears not the slightest resemblance to ancient Rome. Unlike all previous European empires, it has no significant overseas settler populations in any of its formal dependencies and no obvious desire to acquire any. ... It exercises no direct rule anywhere outside these areas, and it has always attempted to extricate itself as swiftly as possible from anything that looks as if it were about to develop into even in direct rule.[179]