Khalkin Gol War 1939

The Japanese idea of establishing another puppet state to be called Mengukuo, on the territory of Inner Mongolia and the Mongolian People's Republic, likely contributed to the escalation of the opposing Mongolia-Manchukuo border claims to territory along Khalkin Gol (River) into a war between their sponsors, Japan and the USSR. Japan supported the claim that Khalkin Gol was the boundary between easternmost Mongolia and their client state of Manchukuo. When Soviet troops occupied the territory between the river and Nomonhan (about 20km to the east), in support of their client state of Mongolia, the Japanese responded with force.

On May 11, 1939, Japanese troops of Kwangtung Army attacked the territory occupied by the Red Army. The offensive achieved some immediate success, penetrating up to 20km toward the river, before the defending Soviet army checked their advance. The Soviets then built up a combined Soviet-Mongolian army outnumbered the Japanese by a ratio of two to one. In August, after battling for 11 days, the Soviet-led army had forced the Japanese troops to retreat back to Nomonhan. Now, the Japanese army began to reinforce in preparation for a renewed offensive. However, the governments of Japan and the Soviet Union negotiated a ceasefire on September 15, 1939.

The diplomatic situation had changed substantially during the fighting. Japan learned of the Nazi-Soviet Pact and on August 23rd it renounced the Anti-Comintern Pact with Germany. Meanwhile, the severity of the defeat the Red Army inflicted on the Japanese forces at Khalkin Gol encouraged Japan to concentrate its war effort on a southward drive in China and Southeast Asia – a strategy that helped propel Japan ever closer to war with the United States and Great Britain and their allies. The Khalkin Gol border dispute was settled in June 1940, largely in favor of the Soviets and Mongolians. On April 13, 1941, Japan and the Soviet Union signed a treaty of neutrality.

Notes

[1] Clodfelter reports 8,440 Japanese battle deaths.

References

Brownstone and Franck, 427; Clodfelter, 668-9; COW136; Dupuy and Dupuy, 1143; Japan - A Country Study.

Category

Inter-State War

Region

East Asia

Belligerents

Japan, Mongolia, USSR

Dispute

Territory

Initiation Date

May 11, 1939

Termination Date

September 16, 1939

Duration

3 months, 26 days
(118 days)

Outcome

Unsettled Dispute

Fatalities

Total: 28,000
Japan: 20,000^[1]
Mongolia: 3,000
USSR: 5,000

Magnitude

4.4