Allied prisoners of war of Japan

During the Second World War, prisoners of war (POWs) from Allied countries (also known in the UK as Far East prisoners of war, FEPOW:4) suffered extreme mistreatment in Japanese captivity, characterized by forced labor, severe malnutrition, disease, physical abuse, and mass executions. The Imperial Japanese Army disregarded international conventions on the humane treatment of POWs, subjecting captives to brutal conditions in prison camps, on forced marches, and aboard transport ships known as "hell ships". Many POWs were forced into labor on large-scale infrastructure projects, including the infamous Burma-Siam Railway, where tens of thousands perished. Japanese forces also conducted biological and chemical experiments on prisoners, most notably through the activities of Unit 731.

Japan had previously ratified the Hague Conventions of 1899 and 1907, which outlined the rights of prisoners of war, but did not ratify the Geneva Convention. The Japanese military's treatment of POWs in World War II was significantly harsher than its treatment of prisoners during the Russo-Japanese War and World War I, reflecting the country's growing militarization, nationalist ideology, and rejection of Western norms. While the Allies generally adhered to the Geneva Convention in their treatment of Japanese POWs, Japan, like other Axis Powers and the USSR, did not reciprocate,:4–5:237 instead embracing a military culture that viewed surrender as dishonorable and POWs as unworthy of protection.

The death rate for Western Allied POWs in Japanese custody was significantly higher than that in German or Italian hands, reaching nearly 30% for some nationalities. Non-Western POWs, including Chinese, Filipino, and Indian soldiers, often faced even worse conditions, with mass executions of Chinese prisoners being common. The mistreatment of POWs became a focal point of post-war war crimes trials, though many of those responsible evaded prosecution. The suffering endured by Allied prisoners left a lasting impact on historical memory, shaping post-war perceptions of Japan's role in World War II. Despite extensive documentation and survivor accounts, the subject remains contentious, with some instances of denial or minimization of related war crimes in Japan.