World War II by country World War II by country Nearly every country and territory in the world participated in World War II, with the exception of only a few nations which remained neutral. The Second World War pitted two alliances against each other, the Axis powers and the Allied powers. The leading Axis powers were Nazi Germany, the Kingdom of Italy and the Empire of Japan; while the United Kingdom, the United States, the Soviet Union and China were the "Big Four" Allied powers. The countries involved in or affected by World War II are listed here alphabetically, with a description of their role
Allied Force Headquarters in command of AFHQ until January 1944, overseeing the Allied invasion of Sicily (with the codename of Operation Husky), which began on 10 July 1943 and the Allied invasion of the Italian mainland (codenamed Operation Baytown and Operation Avalanche), on 3 September 1943. Eisenhower then a full general, returned to the United Kingdom in December to assume command of the Allied forces assembling for Operation Overlord, the Allied invasion of Normandy, scheduled for the spring of 1944. He was succeeded by General Sir Henry Maitland Wilson. Wilson's title became Supreme Commander, Mediterranean Theater of Operations. Wilson was in command for