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
Operation Avalanche tie down German forces, keeping them away from the planned invasion of Normandy – Operation Overlord. However, General George Marshall and much of the American staff wanted to undertake no operations that might delay the Normandy invasion. When it became clear that Operation Overlord could not be undertaken in 1943, it was agreed forces in North Africa should be used to invade Sicily, with no commitment made to any follow-up operations. Joint Allied Forces Headquarters AFHQ were operationally responsible for all Allied land forces in the Mediterranean theatre and it was they who planned and commanded the invasion of Sicily