Battle of Mutanchiang

In February 1945 at the Yalta Conference, the Soviet Union under Joseph Stalin agreed to enter the war against Japan within three months' of Germany's defeat. In order to meet this deadline, it was necessary that the Soviet Union and the Western Allies cooperate in stockpiling supplies in the Far East[20] while the Red Army dispatched additional forces along the Trans-Siberian Railway. While the Japanese monitored this buildup, they did not believe the Soviets would be ready to attack until mid-September, resulting in their being taken by surprise when the attack actually began on August 8.[21]

The Japanese force tasked with defending Manchuria, the Kwantung Army, was by this time reduced from the IJA's premier fighting force to a shell of its former self. Having been stripped of most heavy equipment and experienced formations, its forces had an average efficiency of under 30 percent relative to prewar units.[22] The Soviets, on the other hand, hand-picked their best formations from the war in Europe based on their experience against certain types of terrain and enemy defenses.[23] Key to the defense of eastern Manchuria was General Seiichi Kita's First Area Army, based at Mutanchiang. Subordinate to this Area Army were the Japanese Fifth and Third Armies, of which the Fifth Army, led by Lieutenant General Noritsune Shimuzu, would play the main part in the coming battle. Overall strategy in the event of a Soviet attack was for an initial stand to be made near the borders, allowing the main Kwantung Army forces to withdraw to a "redoubt area" around the city of Tunghua. Unfortunately for the Japanese, neither the redeployments necessary for such a plan nor the fortifications at Tunghua were ready at the commencement of hostilities.[24]

The Soviet strategy, on the other hand, was exactly the opposite. In order to prevent the Kwantung Army from withdrawing to relative safety, the Red Army leadership under Marshal A.M. Vasilevsky planned a lightning assault in the form of a pincer movement, designed to stun and envelop the Japanese before they had a chance to escape.[25] In charge of operations opposite the First Area Army in Eastern Manchuria was Marshal K.A. Meretskov's First Far Eastern Front, whose objectives were to seize Jilin and cut off Manchuria from Korea.[26] These orders would take Meretskov's forces through the vital centers of Mutanchiang and Harbin. Leading the drive to Mutanchiang would be A.P. Beloborodov's 1st Red Banner Army and N.I. Krylov's Fifth Army, fully half of their parent Front's combat strength.

Having denounced its neutrality pact with Japan on April 5, Soviet forces crossed the border into Japanese-held Manchuria at midnight on August 8, 1945, achieving tactical surprise. In response, the Imperial General Headquarters ordered the commencement of all-out military action against the Soviet Union.[27] The Soviet–Japanese War had begun in earnest.

The first phase of the battle

The initial thrust was opposed by the 135th, 126th, and 124th infantry divisions of the Japanese 5th Army, which were driven back by the Soviet attack. The main land routes to Mutanchiang consisted of two mountain passes, one to the north and one to the east of the city. The Soviets would make use of both of them, with the 1st Red Banner Army attacking from the north and the 5th Army attacking from the east.[28] The Soviets were ultimately successful in their advance, but losses, especially in tanks, were very heavy. Of particular concern were concealed anti-tank guns as well as suicide bombers with explosives strapped to their backs.[29] These, together with the torrential rain, made advancing difficult.

By August 12 the Japanese 5th Army had been compressed into a semicircle around Mutanchiang. While the Soviets continued to gain ground, the shrinking Japanese lines and their recovery from the initial attack meant that resistance in all sectors was stiffening. Despite showing an ability to recover and repair damaged tanks which both impressed and disheartened the Japanese,[30] Soviet armored losses continued to mount: in one sharp action the 257th Tank Brigade's original strength of 65 tanks had been reduced to 7.[30] Japanese losses were also severe: on the morning of August 13, a convoy of troop trains was ambushed by Soviet tanks, which destroyed the trains and killed approximately 900 Japanese soldiers. Thirty cars were lost, carrying 24 artillery pieces, 30 vehicles, 800 rifles, and 100 machine guns. Among those who barely survived was the commander of the IJA 135th division.[30]

Over the course of the next few days the Japanese continued resistance around Mutanchiang from a series of fortified hills, from which they could rain fire on the Soviet corridors.[31] The Red Army was forced to take these hills one by one, using its preponderance in armor and artillery to neutralize the defenses. During the struggle for Mount Shozu, an important Japanese stronghold, the weight of Soviet fire was so great that it appeared as if the top of the mountain had been blown completely off.[32] Suicide bombers and anti-tank guns remained an ever-present threat: on August 14 Japanese forces near Ssutaoling[lower-alpha 1] knocked out 16 Soviet tanks with direct fire and a further 5 with suicide bombers; the latter vehicles being destroyed by only 5 men.[33] Nevertheless, these attacks were reliant on the fanaticism of the individual Japanese soldier, and while they resulted in the destruction of Soviet armor, Japanese human losses were much higher.

The final phase of the battle

The unexpectedly strong resistance around Mutanchiang caused Marshal Meretskov to change the 5th Army's objective from capturing the city to simply bypassing it, leaving the 1st Red Banner Army to take the city itself.[34] This move threatened the integrity of the entire Japanese defense, and the situation became untenable. On August 15, General Shimizu, acting under the authorization of General Kita, ordered the IJA 5th Army to begin a withdraw, leaving only minor forces behind as a rearguard.[34] At 0700 hours on August 16, the final Soviet assault on Mutanchiang began. Rocket artillery pulverized the remaining Japanese defenders, while tanks and infantry rushed forward to attack the city itself. However, in attempting to cross the Mudan River to the east of Mutanchiang, the 1st Red Banner Army found that all three bridges spanning it had been destroyed by the Japanese, and heavy fire from the opposite bank made a landing by boat impossible.[35] In response, the Soviet 22nd Rifle Division crossed the river farther to the north and surprised the Japanese defenders from behind, forcing their withdrawal. This allowed the bulk of the 1st Red Banner Army to cross directly over the river and begin the assault on the downtown area.[35] By 1100, Soviet forces began the room-by-room conquest of Mutanchiang in the face of fanatical resistance. By 1300, the Japanese rearguard had abandoned the city under pressure from the south, east, and northwest, leaving only scattered groups of diehards to continue resistance from the devastated buildings.[35] As the 1st Red Banner Army invested Mutanchiang, the Soviet 5th Army to the south continued its advance westward, enveloping and destroying the Japanese 278th Infantry Regiment, the survivors of which mounted a last-ditch banzai charge rather than surrender.[36] By the end of the day, all of Mutanchiang had fallen into Soviet hands, and the battle for the city was over.[35] Shortly afterward, the main strength of the Kwantung Army laid down its arms in surrender as per the Emperor's broadcast. The Battle of Mutanchiang, and World War II, had come to an end.

Through the speed and audacious conduct of their offensive, the Soviet 5th and 1st Red Banner Armies won a major victory at Mutanchiang, advancing 150-180 kilometers and capturing the objective fully ten days ahead of schedule.[37] The rapid advance preempted Japanese plans to establish a strong initial defensive line before Mutanchiang and forced them to begin their withdrawal early, fragmenting their forces.[37] Despite these successes, however, stiff Japanese resistance and the fact that the main strength of the Soviet Armies failed to keep pace with their spearheads meant that the bulk of the IJA 5th Army was able to withdraw, albeit at only 50% of its already below-standard effectiveness.[37][38] Soviet leaders acknowledged this, admitting the retreating Japanese still constituted "a very considerable force."[39] All of this would matter little though, as the war ended before any further major fighting could take place.

Casualties on both sides were heavy. The Japanese reported 25,000 overall casualties, including 9,391 killed, from both the 5th Army and other units subordinate to the 1st Area Army that took part in the fighting. They also admitted the loss of 104 artillery pieces. In exchange, they claimed to have inflicted 7,000-10,000 Soviet casualties and destroyed 300-600 tanks. These claims may actually have been an underestimate:[2] Soviet calculations place the 1st Far Eastern Front's losses in the Manchurian campaign as 21,069, including 6,324 killed, captured, or missing and 14,745 wounded and sick. At least half of these were incurred during the fighting at Mutanchiang.[15]