The Malayan Emergency, also known as the Anti–British National Liberation War (1948–1960), was a guerrilla war fought in British Malaya between communist pro-independence fighters of the Malayan National Liberation Army (MNLA) and the military forces of the British Empire and Commonwealth. The communists fought to win independence for Malaya from the British Empire and to establish a socialist economy, while the Commonwealth forces fought to combat communism and protect British economic and colonial interests. The conflict was called the "Anti–British National Liberation War" by the MNLA, but an "Emergency" by the British, as London-based insurers would not have paid out in instances of civil wars.On 17 June 1948, Britain declared a state of emergency in Malaya following attacks on plantations, which in turn were revenge attacks for the killing of left-wing activists. Leader of the Malayan Communist Party (MCP) Chin Peng and his allies fled into the jungles and formed the MNLA to wage a war for national liberation against British colonial rule. Many MNLA fighters were former members of the Malayan Peoples' Anti-Japanese Army (MPAJA), a communist guerrilla army previously trained, armed and funded by the British to fight against Japan during World War II. The communists enjoyed strong support from the ethnic Straits Chinese population, most of whom lived in dire poverty, suffered racial persecution, and were barred from voting. The communists' belief in class consciousness, and both ethnic and gender equality, inspired many indigenous people and women to join both the MNLA and its undercover supply network the Min Yuen.

After establishing a series of jungle bases the MNLA began raiding British colonial police and military installations. Tin mines and rubber plantations were attacked by the MNLA to gain independence for Malaya by bankrupting the British occupation. The British attempted to starve the MNLA using scorched earth policies through food rationing, the killing of livestock, and the aerial spraying of herbicides including Agent Orange. British attempts to defeat the communists included extrajudicial killings of unarmed villagers, in violation of the Geneva Conventions. The most infamous example is the Batang Kali massacre, which the British press have referred to as "Britain's Mỹ Lai". The Briggs Plan was enacted to imprison 400,000 to one million civilians into concentration camps, which were referred to by the British as "New villages". Many Orang Asli indigenous communities were also targeted for internment because the British believed that they were supporting the communists.Although the emergency was declared over in 1960, communist leader Chin Peng renewed the insurgency against the Malaysian government in 1967. This second phase of the insurgency lasted until 1989.