toward India within the South-East Asian theatre of World War II, the United Kingdom hastily withdrew their 2nd Royal Tank Regiment and 7th Hussars Stuart tank units (which also contained some M2A4 light tanks) from North Africa, and deployed them against the Japanese 14th Tank Regiment. By the time the Japanese had been stopped at Imphal, only one British Stuart remained operational. When the U.S. entered the war in 1941, it began to supply China with AFVs, including M3 Stuarts, and later M4 Sherman medium tanks and M18 Hellcat tank destroyers, which trickled in through Burma. Although the U.S. light tanks had proven effective in jungle warfare, by late 1943, U.S. Marine Corps tank battalions were transitioning from their M3/M5 light tanks to M4 medium tanks, mostly for the much greater high-explosive blast effect of the M4's 75mm gun, which fired a much larger shell with a heavier explosive payload. Obsolescence and replacement When the U.S. Army joined the North African Campaign in late 1942, Stuart units still formed a large part of its armor strength. After the disastrous Battle of Kasserine Pass, the U.S. quickly followed the British in disbanding most of their light tank battalions and reorganizing medium tank battalions to include one company of light tanks, where the Stuarts mostly performed the traditional cavalry missions of scouting and screening; for the rest of the war, most U.S. tank battalions had three companies of M4 Shermans and one company of M3s or M5/M5A1s. In Europe, Allied light tanks were given cavalry and infantry fire support roles since their light main armament was not competitive against heavier enemy armored fighting vehicles. However, the Stuart was still effective in combat in the Pacific Theater, as Japanese tanks were both relatively rare and were lighter in armor than even Allied light tanks. Japanese infantrymen were not well equipped with anti-tank weapons, and as such had to use close assault tactics. In this environment, the Stuart was only moderately more vulnerable than medium tanks. Though the Stuart was to be completely replaced by the newer M24 Chaffee, the number of M3s/M5s produced was so great (over 25,000 including the 75mm HMC M8) that the tank remained in service until the end of the war, and well after. In addition to the U.S, UK and Soviet Union, who were the primary users, it was also used by France (M3A3 and M5A1), China (M3A3s