Soviet–Japanese border conflicts

The Soviet–Japanese border conflicts were a series of battles between the Soviet Union, led by Joseph Stalin, and Japan, led by Hirohito. These fights also involved Mongolia and the area called Manchukuo in Northeast Asia. The troubles began in 1932 and went on until 1939.

Japan had taken over parts of Northeast China, which brought them close to land controlled by the Soviet Union. This made both sides very nervous, and they sometimes crossed into each other’s lands. Small fights and bigger military actions happened between 1935 and 1939. The biggest of these battles was the Battles of Khalkhin Gol in 1939, where the Soviets and Mongolia won, and the borders went back to how they were before.

Because of these conflicts, the Soviet Union and Japan signed the Soviet–Japanese Neutrality Pact in 1941, agreeing to stay out of each other’s way.

Prelude from 1904 to 1932

After the First Sino-Japanese War and the Eight Power Intervention against the Boxer Rebellion in China, control over areas like Manchuria and Korea became weaker. Both the Russian and Japanese Empires wanted to control these areas.

The Russo-Japanese War from 1904 to 1905 started when the Empire of Japan, led by Emperor Meiji, attacked the Russian Pacific Fleet at Port Arthur on the Liaodong Peninsula. After tough fighting, the Russian Empire had to make peace. Japan gained control of Korea, and Russia agreed to leave Manchuria.

Later, during the Russian Civil War after World War I, Japan was involved in the fighting in the Russian Far East. Japan pulled out in 1922.

When Hirohito led Japan to invade Manchuria in 1931–1932, problems began between Manchukuo, the Mongolian People's Republic, and the Soviet Union. There were many border disputes because the borders were not clearly marked and because of secret activities by both sides. Trust between the Soviet Union and Japan grew weaker over time.

Minor clashes between the Soviets and Japanese

1935 Incidents

In early 1935, soldiers from Japan and the Soviet Union had their first shooting. From then until April 1939, there were 108 such fights recorded. One of the first big fights was on January 8, 1935, near a temple called Halhamiao. Soldiers from Mongolia went into an area controlled by Japan, leading to a fight where some soldiers were hurt but no one from Mongolia was hurt.

In June 1935, Japanese and Soviet soldiers fought for the first time directly. A small group of Japanese soldiers was attacked by Soviet soldiers, and one Soviet soldier was killed.

In October 1935, Japanese and soldiers from Manchukuo were attacked by Soviet soldiers while setting up a post. This led to a fight where some soldiers were killed and others were hurt.

1936 border incidents

In February 1936, a Japanese military group was sent to push Mongolian soldiers out of an area. They fought and drove the Mongolian soldiers away, but some Japanese soldiers were hurt, and one small vehicle was destroyed.

In March 1936, another fight happened in a village called Tauran. Mongolian and Soviet soldiers attacked the village, but Japanese forces fought back and drove them away, with many soldiers hurt or killed on both sides.

1937

Kanchazu Island incident

In June 1937, Soviet soldiers crossed into an island on the Amur River. Japanese soldiers fought back, sinking one Soviet boat and scaring off the others. Many Soviet soldiers were killed, but no Japanese soldiers were hurt. The Soviet soldiers later left the island.

Soviet involvement in China 1937–1941 during the Second Sino-Japanese War

In July 1937, Japan invaded China, starting a big war. The Soviet Union helped China a lot during this time, sending many weapons and soldiers to support them. This made tensions between the Soviet Union and Japan even higher.

Battle of Lake Khasan (1938)

Main article: Battle of Lake Khasan

The Battle of Lake Khasan happened from July 29 to August 11, 1938. It began when Japanese forces tried to enter an area the Soviet Union thought was theirs. The Japanese believed the Soviets did not understand where the border should be, based on old treaties.

Fighting occurred, and both sides had losses. Peace was made on August 10, and Japanese troops left the next day. After that, Soviet forces returned to the area.

Major conflicts of 1939

The fight between the Soviet Union and Japan in 1939 is sometimes called the "Forgotten Soviet-Japanese War." It changed Japan's plans during World War II.

Battles of Khalkhin Gol

Main article: Battles of Khalkhin Gol

The Battle of Khalkhin Gol was a big fight between the Soviet Union and Japan. After smaller fights in May and June 1939, bigger battles happened. The Soviets had more soldiers and better weapons. There were three main parts to the battle:

• The Japanese attacked in July but were stopped.
• The Soviets tried to attack in August but were pushed back.
• In late August, the Soviets attacked again and defeated the Japanese.

The Soviets and Mongolia won, and the Japanese left Mongolia. They agreed to stop fighting on September 15, 1939. With no worries about Japan, the Soviet Union later invaded Poland.

Soviet–Japanese Neutrality Pact of 1941–1945

Main articles: Soviet–Japanese Neutrality Pact and Soviet–Japanese War

After losing at Khalkhin Gol, Japan and the Soviet Union agreed to stay neutral toward each other in 1941. Even when Germany attacked the Soviet Union, Japan did not break this agreement and instead focused on Southeast Asia. The Soviet Union ended the pact in 1945 and declared war on Japan, leading to the Soviet invasion of Manchuria.

Portrayal in media

The fights between Japan and the Soviet Union at the start of World War II are shown in the South Korean film My Way. In this film, Japanese soldiers fight and are captured by Soviet forces.

The Japanese novel The Wind-Up Bird Chronicle by Haruki Murakami talks about Japan’s time in North China from 1931 to 1948, including the Soviet–Japanese border conflicts. Two characters in the book were in the Kwantung army and were affected by these events. The book describes these events, and they are important to the story.