The WPC immediately received funding and weapons from the Soviet Union, as Stalin was opposed to Japanese influence and sought to establish another satellite state in addition to the already existing Mongolia and East Turkestan. On 25 April, the Chinese National Liberation Army (CNLA), the WPC's armed wing, launched simultaneous revolts in Manchukuo and Mengjiang, which these states' security forces failed to put down.

Japan initially limited itself to giving the Manchurians and Inner Mongolians weapons, but, in mid-May, the conservative government of Shigeru Yoshida decided to intervene, redeploying all units in China proper to Manchuria. The IJA used similar counterinsurgency tactics to the ones the French had successfully used in Indochina, and things initially went well for the Japanese.

On 2 July 1951, Communist Mongolia declared war on Mengjiang in order to achieve Mongolian leader Khorloogiin Choibalsan's goal of building a Greater Mongolia. The Mongolian People's Army was beaten back by both the Japanese and the CNLA, and Mongolia withdrew from the conflict after Choibalsan died on 26 January 1952.

In 1953, Korean communists led by Kim Tu-bong took advantage of the distraction of Japanese troops to launch an independence uprising, but it was suppressed. Despite this, the distraction plan worked, as the tide of the war began to shift in favour of the WPC.

Mengjiang ceased to exist on 14 February 1954, when its capital Kalgan fell to the CNLA. Communist leader Zhou Enlai proclaimed a provisional revolutionary government and launched a full-scale offensive against Manchukuo.

Following the Right Socialist victory in the June 1955 Japanese elections, Japan pulled out of Manchukuo, allowing its capital Xinjiang to fall on 3 August. Zhou then founded the Democratic Republic of China, which he led until his death in 1976.