World War II: Allied forces are defeated by the Japanese at the Battle of Malaya and retreat to Singapore.

World War II or the Second World War was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

The Malayan campaign, referred to by Japanese sources as the Malay Operation , was a military campaign fought by Allied and Axis forces in Malaya from 8 December 1941 – 15 February 1942 during the Second World War. It was dominated by land battles between British Commonwealth army units and the Imperial Japanese Army, with minor skirmishes at the beginning of the campaign between British Commonwealth and Royal Thai Police. The Japanese had air and naval supremacy from the opening days of the campaign. For the British, Indian, Australian, and Malayan forces defending the colony, the campaign was a total disaster.