guerrilla movement formed originally to oppose the Japanese occupation of Malaya during World War II. In December 1941 a rapid Japanese invasion commenced, and within 10 weeks it had conquered Malaya. British military forces had prepared for this possibility by training small Malayan guerrilla groups. Once war became a reality, the guerrillas organized the MPAJA. This army consisted primarily of Chinese Communists, with smaller numbers of Kuomintang (Nationalist) Chinese and some Malays. Because of the Chinese majority in the army, the Malayan Communist Party was able to infiltrate and indoctrinate the guerrillas and to stress that postwar Malaya would become Communist through their efforts.

Because the MPAJA was the only local resistance to the Japanese, Great Britain supplied it with officers and supplies. The army also received supplies and recruits from Chinese and Malays outside the jungle. The number of jungle fighters rose from about 3,000 in 1942 to 7,000 men and women in 1945. Upon British advice the MPAJA avoided large-scale action against the Japanese, but after the war its Communist-indoctrinated members emerged as heroes. This army attempted a brief, unsuccessful seizure of political power before the British military returned. The MPAJA officially disbanded when most of its members turned in their arms to the returning British forces. Its leadership, organization, and many of its arms remained underground, however, until the uprising of the Malayan Communist Party in 1948.