During 1931, the KMT started a campaign that was designed to completely eradicate all the communists from the country. As the two parties began to have more serious conflicts, the Japanese military saw an opportunity to take more lands that were claimed by the Chinese. By planting a bomb on a Manchurian railway, the Japanese military created a scenario in which it looked like the Chinese Civil War was affecting other nations. Following the bombing, Japan claimed the area after a successful invasion.

Tired from four years of attacks by the KMT and realizing their own vulnerability to other outside threats, the CCP decided to relocate to a more secure area in 1934. It was reported that roughly 80,000 loyal CCP members left Jiangxi to look for a new base. After three months of seeking a new home, Mao Zedong took control over the Red Army, the forces of the CCP. As Japan expanded into Chinese territories on the eastern side of the country and as the KMT tried to wipe out the CCP farther inland and toward the middle of the country, the men had to march far to the west and then north to escape persecution from both sides. By the time they finally reached the safer areas of China, they had crossed more than 6,000 miles, which included traversing over mountains. This became known as the Long March.

During the march, which was as long as approximately 9,000 kilometres, Mao Zedong began his rise to power. His leadership under the tremendously difficult conditions gave the army a great appreciation for him and gave Mao a deeper understanding of the skills necessary to lead a vast nation of people. After the Long March was completed, the KMT took control of the government. This success would be short-lived, however, as the Japanese invaded China in 1937.

In order to repel the Japanese forces, which would not be fully accomplished until the Sino-Japanese War's end, the KMT was forced to ally itself with the Red Army, which put the Red Army in a position of great strength after the war. When that happened, Mao was in a place of authority from which he could help the Red Army (and CCP) seize control of China