How did Germany and Japan build empires in Europe and Asia, and how did the Allies defeat them?

World war broke out because Hitler’s and Japan’s ambitions were essentially unlimited. Nazi soldiers scored enormous successes in Europe until late 1942, establishing a vast empire of death and destruction. Japan attacked the United States in December 1941 and then moved to expand its empire throughout Asia and the Pacific Ocean. Eventually, the mighty coalition of Britain, the United States, and the Soviet Union, which Winston Churchill called the Grand Alliance, overwhelmed the aggressors in manpower and military strength. Thus the Nazi and Japanese empires proved short-lived.