Battles of Khalkhin Gol - August: Zhukov's Strike

August: Zhukov's Strike

The Japanese regrouped and planned a third major offensive against the Soviets for 24 August. However, with war apparently imminent in Europe, Zhukov planned a major offensive on 20 August, to clear the Japanese from the Khalkhin Gol region and end the fighting. Zhukov assembled a powerful armored force of three tank brigades (the 4th, 6th and 11th), and two mechanized brigades (the 7th and 8th, which were armored car units with attached infantry support). This force was allocated to the Soviet left and right wings. The entire Soviet force consisted of three rifle divisions, two tank divisions and two more tank brigades (in all, some 498 BT-5 and BT-7 tanks), two motorized infantry divisions, and over 550 fighters and bombers. The Mongolians committed two cavalry divisions.

By contrast, at the point of contact, the Kwantung Army had only Lieutenant General Michitarō Komatsubara's 23rd Infantry Division, which with attached forces was equivalent to two light infantry divisions. Its headquarters had been at Hailar, over 150 km (93 mi) from the fighting. Japanese intelligence had also failed to detect the scale of the Soviet buildup or the scope of the imminent offensive.

Zhukov decided it was time to break the stalemate. At 0545 on 20 August 1939, Soviet artillery and 557 fighters and bombers attacked Japanese positions, the first fighter/bomber offensive in Soviet Air Force history. Approximately 50,000 Soviet and Mongolian soldiers of the 57th Special Corps defended the east bank of the Khalkhyn Gol. Three infantry divisions and a tank brigade crossed the river, supported by massed artillery and the best planes of the Soviet Air Force. Once the Japanese were pinned down by the attack of Soviet center units, Soviet armored units swept around the flanks and attacked the Japanese in the rear, achieving a classic double envelopment. When the Soviet wings linked up at Nomonhan village on 25 August, the Japanese 23rd Infantry Division was trapped. On 26 August, a Japanese counterattack to relieve the 23rd Division failed. On 27 August, the 23rd Division attempted to break out of the encirclement, but also failed. When the surrounded forces refused to surrender, they were again hit with artillery and air attacks. By 31 August, Japanese forces on the Soviet side of the border were destroyed, leaving remnants of the 23rd Division on the Manchurian side. The Soviets had achieved their objective.

Komatsubara refused to accept the outcome and prepared a counteroffensive. This was canceled when a cease-fire was signed in Moscow. While Zhukov defeated the Japanese forces from Soviet territory, Joseph Stalin had made a deal with Nazi Germany. After the Soviet success at Nomonhan, Stalin decided to proceed with the Molotov-Ribbentrop Pact, which was announced on 24 August. Though World War II broke out in Europe on 1 September, the Soviet Union had declared its neutrality there. This meant the Soviet Union could concentrate all its forces in the East if needed, and the Japanese position was clearly hopeless.

With no further threat of a second front from Japan, Stalin was free to concentrate on war in Europe, and the Soviet Union and Japan agreed to a cease-fire on 15 September; it took effect the following day. Free from a threat in the Far East, Stalin proceeded with the Soviet invasion of Poland (1939) on 17 September.