Pig War (1906–1908)

At the beginning of the 20th century, Serbia was economically a satellite of the Habsburgs, its major export being pork, most of which was bought by the Austro-Hungarian Empire. When Serbia started trying to evade economic and political control by the Habsburgs and build links with other countries, particularly Bulgaria and France, the Hungarian government decided to punish the Serbs with economic sanctions. Specifically, in an attempt to reduce its economic dependence on the Austro-Hungarian Empire, Serbia began to import French rather than Austrian munitions in 1904 and established a customs union with Bulgaria in 1905, ending the sale of tariff-laden Austrian goods in Serbia.

Long used to setting economic policy, Austria responded in April 1906 by closing its borders to Serbian pork. Serbia refused to bow to Vienna, gained French investment to build new packing plants for international trade, began to order materials from Austria's rival Germany and pressured the Austrian-administrated provinces of Bosnia and Herzegovina for a trade outlet on the Adriatic Sea. That caused Austria to give up by March 1908, as shown by the trade statistics of the period in question, published in the 1911 edition of the Encyclopædia Britannica:

Russia supported Serbia's actions, and war between Austria-Hungary and Russia was averted only because of a German ultimatum in 1909 that demanded the end of Russian aid to Serbia.

• Austro–Serbian Alliance of 1881

• Misha Glenny, The Balkans 1804-1999: Nationalism, War and the Great Powers (London: Granta, 1999), pp. 281–2.