Due to the naval nature of the Pacific campaign, steel for warship production took precedence over tanks for the IJA, creating by default an IJA light tank that performed admirably in the jungle terrain of the South Pacific. By the same measure, although the US was not hampered by industrial restrictions, the U.S. M3 light tank proved to be an effective armoured vehicle for fighting in jungle environments. With the IJA’s drive 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, 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.