News of the signing, on August 25, of a formal treaty of mutual assistance between Great Britain and Poland (to supersede a previous though temporary agreement) caused him to postpone the start of hostilities for a few days.
More than one million Soviet troops and tens of thousands of civilians died in the defense of the city, but the destruction of two entire German armies marked the beginning of the end of the Third Reich.
The Allied landings at Normandy on June 6, 1944, opened a second front in Europe, and Germany’s abortive offensive at the Ardennes in the winter of 1944–45 marked the Third Reich’s final push in the west.
World War II began in Europe on September 1, 1939, when Germany invaded Poland. The Allied powers were led by Winston Churchill (United Kingdom); Joseph Stalin (Soviet Union); Charles de Gaulle (France); and Franklin D. The war in the Pacific turned against Japan during the Battle of Midway (June 3–6, 1942), an American victory that destroyed the Japanese first-line carrier force and, together with the Battle of Guadalcanal, ended Japan’s ability to prosecute an offensive war.
Great Britain and France responded by declaring war on Germany on September 3. The tide of the war in Europe shifted with the Soviet victory at the Battle of Stalingrad (February 1943).
The Red Army advanced from the east and effectively claimed all the territory under its control for the Soviet sphere. Hitler committed suicide on April 30, 1945, and the war in Europe ended on May 8.
The American “island hopping” campaign had destroyed key Japanese installations throughout the Pacific while allowing bypassed islands to wither on the vine.
But even after due allowance has been made for the effects of the American stock market’s "Great Crash" in 1929 and for the policies of the United States Federal Reserve System, there can be little doubt that the deepest roots of the crisis lay in the several chronic infirmities that World War I had inflicted on the international political and economic order.
The war exacted a cruel economic and human toll from the core societies of the advanced industrialized world, including conspicuously Britain, France, and Germany.
Hundreds of thousands were killed in firebombings of Japanese cities, and the atomic bombing of Hiroshima and Nagasaki in August 1945 knocked Japan out of the war.
Along with World War I, World War II was one of the great watersheds of 20th-century geopolitical history.