When Russian archives were widely open and Chinese documents had been already published on the late 1990’s, a hot debate on the Chinese Entry into the Korean War was opened. The discrepancy was revealed between the Russian and Chinese version of Mao’s 2 October 1950 message to Stalin on Chinese Entry into the Korean War. While Mao made a decision not to send any troops then in the Russian version, he said Stalin to make a decision to send 12 divisions on 15 October in Chinese version.
Mao’s handwriting message which exists at the Chinese Communist Party Central Archives was not sent. Mao verbally delivered the reluctant message on entry into the Korean War to Roshchin and authorized the Soviet Ambassador to convey it to Stalin.
Due to direct confrontation with the United States, the Soviet Union and China were originally reluctant to enter the Korean War. After Stalin discussed China's entry into war with Zhou Enlai from on 9 October, they agreed on the evacuation of North Korea and the retreat of Korean troops to the Northeast China. As Mao Zedong believed that the US control of entire Korea would pose a threat to China, he became less reluctant than Stalin. Mao's hesitation partially came from his calculation to receive more military help from Soviet Union such as air umbrella. Despite Stalin’s reluctance, Mao made the final decision to enter the Korean War on 13 October 1950. Had China not intervened in the Korean War, Mao would have lost an opportunity to assume a leadership role in Asian revolutionary movement.