Even after the death of Hitler and the capitulation of the Nazis WWII didn’t fully end for the Soviet Union. There was still one more major challenge to face but this time way out to the east. Let’s take a look at who the Kwantung army was and how the Soviets ultimately defeated them.

The Kwantung Army (関東軍, Kantōgun) was a powerful branch of the Imperial Japanese Army stationed in Manchuria from the early 20th century until Japan’s defeat in World War II. While its primary focus was controlling northeast China, the Kwantung Army also played a crucial role in Russian and Soviet history, engaging in conflicts that shaped the geopolitical landscape of East Asia.

Image above: The Kwantung Army on the march against the Soviets in 1939

Origins and Early Role

The Kwantung Army was established in 1906 following Japan’s victory in the Russo-Japanese War (1904–1905). This conflict, which ended with the Treaty of Portsmouth, marked Japan’s emergence as a major military power and its first decisive victory over a European empire—Russia.

Initially, the Kwantung Army was tasked with protecting Japan’s interests in the Kwantung Leased Territory, which included the strategic port of Port Arthur, as well as the South Manchuria Railway, both of which Japan had acquired from Russia. Over time, however, the army grew increasingly independent, often acting against the directives of Tokyo and pushing for further expansion into Manchuria and beyond.

The Kwantung Army and the Russian Civil War

Following the Bolshevik Revolution of 1917, Japan joined the Allied Intervention in the Russian Far East. Elements of the Kwantung Army were deployed to Siberia and Vladivostok alongside other foreign forces. Their objectives included suppressing Bolshevik forces, supporting anti-Communist White Russian factions, and expanding Japanese influence in the region.

Despite initial gains, the intervention proved unsuccessful. Facing strong resistance from the Red Army and growing domestic opposition, Japan withdrew its forces in 1922. This failure left a lasting impression on Soviet leadership, fostering deep distrust of Japanese militarism that would influence future conflicts.

The Manchurian Incident and Soviet-Japanese Border Wars

In 1931, the Kwantung Army orchestrated the Mukden Incident, a staged attack used as a pretext to invade and occupy Manchuria. This led to the creation of the puppet state of Manchukuo, bringing Japanese forces directly to the Soviet border.

The Kwantung Army’s presence in Manchuria triggered a series of violent clashes with the Soviet Union. The Battle of Lake Khasan (1938) and the Battle of Khalkhin Gol (1939) were pivotal conflicts where Soviet forces, led by Georgy Zhukov, delivered a crushing defeat to the Japanese. These battles demonstrated the Red Army’s growing strength and forced Japan to reconsider its northern expansionist ambitions.

In response, Japan signed the Soviet-Japanese Neutrality Pact in 1941, ensuring that the two nations would avoid open conflict while Japan focused on its campaigns in the Pacific and Southeast Asia.

The Soviet Invasion and the Kwantung Army’s Downfall

The Kwantung Army’s fate was sealed in August 1945, when the Soviet Union, renouncing the neutrality pact, launched a massive invasion of Manchuria in Operation August Storm. The Red Army, battle-hardened from the Eastern Front, overwhelmed the Kwantung Army in a matter of days.

By this point, the Kwantung Army had been significantly weakened, as many of its best units had been redeployed to fight American forces in the Pacific. The Soviet offensive was swift and devastating, leading to Japan’s rapid surrender and the end of World War II. The USSR reclaimed lost territories, including South Sakhalin and the Kuril Islands.

Image above: Surrendered Kwantung Army soldiers being returned to Japan in 1946

Legacy in Russian and Soviet History

The Kwantung Army’s actions had a lasting impact on Soviet-Japanese relations. Its aggressive expansionism contributed to decades of tension, influencing Soviet military strategy in the Far East. The Red Army’s victory in 1945 not only dismantled Japanese imperial ambitions but also solidified Soviet dominance in Northeast Asia, setting the stage for Cold War rivalries in the region. Concern of a resurgent Japan that will eventually throw of the yoke of Washington are often discussed by Moscow-based analysts. With the very first Japanese politicians beginning to openly defy Trump, at least verbally, this may happen sooner than one would think.

The Kwantung Army was more than just a Japanese military force in China—it was a key player in the struggles between Japan and Russia (later the USSR) for control of East Asia. Its defeats at the hands of the Red Army in 1939 and 1945 marked turning points in the region’s history, demonstrating Soviet military strength and reshaping the post-war order. The Kwantung Army’s legacy remains a reminder of the turbulent conflicts that defined early 20th-century Asia.