Its predecessors were various Counter-Japanese volunteer armies organized by locals and the Manchuria branches of the Chinese Communist Party (CCP).

Li Zhaolin was sent from Liaoyang to the county committee of Zhuhe to form a local guerrilla force.

Feng Zhongyun was sent to Tangyuan as the representative and inspector of the Manchuria provincial party committee to form guerrillas.

As a result, guerrilla forces led by communists were ordered by the Manchuria provincial party committee to be rearranged as Red armies and to fight independently.

The letter pointed out the danger of "leader's collusion instead of people's united front" and requested to put forward the slogan to go to the stage of agrarian revolution.

At the same time, the CCP's delegation to the Comintern also took a series of measures in its organization to try to eliminate the influence of the Letter of February 22.

Cadres were sent back from the USSR to Manchuria to make clear instructions and future tasks of the united front.

The letter called for a new policy, that was, the implementation of the all-out Counter-Japanese united front, regardless of party, class, or ethnicity.

[2] In February 1936, communist leaders, including Yang Jingyu, Li Zhaolin, Zhou Baozhong, Zhao Shangzhi, and Wang Detai, jointly issued the Declaration of the Unified Organization of Northeast Counter-Japanese United Army.

This led many Koreans to choose Manchuria as a place to resist Japanese imperialism in their homelands following the March 1st Movement of 1919 and the later foundation of the Provisional Government of the Republic of Korea.

This was a squad of girl guerrillas, aged 13 to 23; after a long firefight with overwhelming Japanese forces who mistook them for a much larger unit, they all jumped into the river, drowning themselves to avoid capture and torture.

Kim Il Sung, later to become the leader of North Korea, was a high-ranking officer in this army, and attained a distinction where he crossed the Manchurian-Korean border and attacked a Japanese police station in Pochonbo at 1937.

It was widely reported by Korean newspapers such as Donga Ilbo and he became famous in Korea as the most prominent leader of the Counter-Japanese movement in the northern half.

In his autobiography, With the Century (세기와 더불어), Kim Il Sung recalled that such conversions of ex-comrades were more painful than fierce Japanese offensives or the tough climate in Manchuria.

A Chinese Communist leader, Peng Zhen, compared the extreme hardship suffered by the army with the Long March.