German troops march through occupied Warsaw, Poland, after invading the nation on September 1, 1939, and igniting World War II.
German Chancellor Adolf Hitler speaks to Nazi party officials in 1939, the year of the German blitzkrieg into Poland. Denmark, Luxembourg, the Netherlands, Norway and Belgium soon fell under German control. When France came under occupation less than a year later, Britain was the only remaining Western European nation fighting the Third Reich, and the United States had not yet entered the war.
In Asia, Japanese troops occupy a strategic point on Chusan Island on July 14,1939, during the Sino-Japanese War. Japan signed the Tripartite Pact in 1940, formally allying with Germany and Italy, and by 1942 most of the Asian Pacific Rim had come under its domination.