USA HISTORY

Detailed explanation-1: -In World War II, the three great Allied powers-Great Britain, the United States, and the Soviet Union-formed a Grand Alliance that was the key to victory.

Detailed explanation-2: -The Allied Powers were led by Great Britain, the United States, and the Soviet Union. These countries were led by British Prime Minister Winston Churchill, US President Franklin D. Roosevelt, and Soviet Premier Joseph Stalin. They formally allied by signing the Declaration by United Nations on January 1, 1942.

Detailed explanation-3: -The third war, arguably the largest single component of World War II, began on 22 June 1941, when the Germans attacked the Soviet Union. Overnight, the Soviet Union became an ally of Britain and a recipient of Lend-Lease aid from the United States.

Detailed explanation-4: -In 1939, on the eve of World War II, Joseph Stalin and Germany’s Nazi Party dictator Adolf Hitler signed the German-Soviet Nonaggression Pact. Stalin then proceeded to annex parts of Poland and Romania, as well as the Baltic states of Estonia, Latvia and Lithuania. He also launched an invasion of Finland.