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
World War II by country Union. Ukraine was part of the Soviet Union during World War II. So see this article's section on the Soviet Union. The United Kingdom was one of the original Allies, entering the war in 1939 to honour its guarantees to Poland. After the fall of France, the United Kingdom was the only Allied nation left in Europe until the invasion of Greece. It remained the only one of the Big Three in the war until 1941 when the Soviet Union was invaded. The United Kingdom was heavily engaged in the Western European, Atlantic, Mediterranean, African and South East Asian theatres,