The Hump was the name given by Allied pilots in the Second World War to the eastern end of the Himalayan Mountains over which they flew military transport aircraft from India to China to resupply the Chinese war effort of Chiang Kai-shek and the units of the United States Army Air Forces (USAAF) based in China. Creating an airlift presented the USAAF a considerable challenge in 1942: it had no units trained or equipped for moving cargo, and there were no airfields in the China Burma India Theater (CBI) for basing the large number of transport aircraft that would be needed. Flying over the Himalayas was extremely dangerous and made more difficult by a lack of reliable charts, an absence of radio navigation aids, and a dearth of information about the weather.

The Second Sino-Japanese War was the war fought between the Republic of China and the Empire of Japan from 1937 to 1945 as part of World War II. It is often regarded as the beginning of World War II in Asia. It was the largest Asian war in the 20th century and has been described as "the Asian Holocaust", in reference to the scale of Japanese war crimes against Chinese civilians. It is known in Japan as the Second China–Japan War, and in China as the Chinese War of Resistance against Japanese Aggression.