Adolf Hitler created the Second World War. He didn’t just start the war, he repeatedly took the initiative to expand it and to point it in new directions. For this reason it is best labeled “Hitler’s War.”
The war really began in late-August 1939 when Hitler made a deal with Russia to divide Eastern Europe. This led to the rapid conquest of Poland (Sept. 1939). In late 1939 Hitler decided on war in the West at the first opportunity. In April and May 1940 German forces over-ran Denmark and Norway. In May and June 1940 they over-ran Holland, Belgium and France, driving the British army off the Continent. Hitler was master of Europe! Except that the British had now concluded that Mr. Hitler was not a very nice person at all. (See: Charles I, Louis XIV, Napoleon I, Kaiser Wilhelm II.) The British fought on, defeating Germany’s planned invasion by winning control of the air over the English Channel in the Battle of Britain. The Germans then turned to starving out the British through submarine warfare in the Battle of the Atlantic. This, too, failed.
Hitler’s victory forced other countries to make choices they didn’t want to make.
Italy declared war just as France fell, then found itself at war with Britain in the Mediterranean. The German conquests in Europe created a vacuum of power in the Far East. Japan sought to exploit this to establish its own supremacy. Germany’s defeat of France and the weak position of Britain terrified the Americans, who began to supply military assistance to the British (Lend-Lease) and to take a strong line against Japan.
Hitler widened the war in1941. He responded to a local challenge by conquering Yugoslavia and Greece in Spring 1941. In June 1941 he launched a huge surprise attack on his Russian ally, capturing millions of prisoners and conquering huge swaths of territory. Alarmed that the war would end without their having any claim on territory, the Japanese attacked. The air raid on Pearl Harbor was followed by the conquest of the Philippines, British Malaya, and the Dutch East Indies. Soon after Pearl Harbor Hitler declared war on the United States. Also in 1941 Hitler ordered the “Final Solution of the Jewish Problem”: this would involve the murder of millions through mass shootings in Russia and the construction of death camps in Poland.
The further course of the war is best summed up in the term “ocean barriers and land bridges.” American forces had to cross vast oceans to reach their German and Japanese enemies. An armada of ships had to be constructed and control of the seas won. Worse still, the Americans and the British divided their resources between the European war, which mattered, and the Pacific war, which did not. In contrast, Germany and Russia had no water barriers between them; they were in continuous contact from Summer 1941 to Spring 1945. Neither side could break off, so the great majority of German casualties were suffered on the Eastern Front, while the British and the Americans made less of a contribution to the defeat of Hitler. Until Summer 1944 the bombing of Germany destroyed cities without harming the German war effort.
The war rushed to an end from Summer 1944 to Summer 1945. The Americans and the British invaded France (June 1944) just as the Russians unleashed a gigantic attack on the Eastern Front. Hitler’s empire crumbled, while the Americans banjoed the Japanese in a remarkable war fought across trackless ocean and trackless island jungle.
War had ruined virtually the whole world, and had revealed that people were capable of anything (Auschwitz and Hiroshima). There would be no easy peace.