Conflict Spreads Around the Globe.
From the last few months of 1940 through the summer of 1941, the conflicts among nations grew into true World War. The East African campaign and Western Desert campaign both began, with largely Italian and British forces battling back and forth across the deserts of Egypt and Libya and from Ethiopia to Kenya. The Tripartite Pact -- a declaration of cooperation between Germany, Italy, and Japan -- was signed in Berlin.
Japanese forces occupied Vietnam, established bases in French Indochina, and continued to attack China. Mussolini ordered his forces to attack Greece, launching the Greco-Italian War and the Balkans Campaign. The Battle of Britain continued as the forces of Germany and Britain carried out bombing raids and sea attacks against each other. The United States began its lend-lease program, which would eventually ship $50 billion worth of arms and materials to to Allied nations. And an ominous new phase began as the Germans established walled ghettos in Warsaw and other Polish cities, rounding up Jews from surrounding areas and forcing them to move in.