By: Camron Alexander
In late August 1939, Hitler and Soviet leader Joseph Stalin signed the German-Soviet Nonaggression Pact, which incited a frenzy of worry in London and Paris. Hitler had long planned an invasion of Poland, a nation to which Great Britain and France had guaranteed military support if it was attacked by Germany. The pact with Stalin meant that Hitler would not face a war on two fronts once he invaded Poland, and would have Soviet assistance in conquering and dividing the nation itself. On September 1, 1939, Hitler invaded Poland from the west; two days later, France and Britain declared war on Germany, beginning World War II.
On April 9, 1940, Germany simultaneously invaded Norway and occupied Denmark, and the war began in earnest. On May 10, German forces swept through Belgium and the Netherlands in what became known as "blitzkrieg," or lightning war. Three days later, Hitler's troops crossed the Meuse River and struck French forces at Sedan, located at the northern end of the Maginot Line, an elaborate chain of fortifications constructed after World War I and considered an impenetrable defensive barrier. In fact, the Germans broke through the line with their tanks and planes and continued to the rear, rendering it useless. The British Expeditionary Force (BEF) was evacuated by sea from Dunkirk in late May, while in the south French forces mounted a doomed resistance. With France on the verge of collapse, Benito Mussolini of Italy put his Pact of Steel with Hitler into action, and Italy declared war against France and Britain on June 10.
On June 14, German forces entered Paris; a new government formed by Marshal Philippe Petain (France's hero of World War I) requested an armistice two nights later. France was subsequently divided into two zones, one under German military occupation and the other under Petain's government, installed at Vichy. Hitler now turned his attention to Britain, which had the defensive advantage of being separated from the Continent by the English Channel. To pave the way for an amphibious invasion (dubbed Operation Sea Lion), German planes bombed Britain extensively throughout the summer of 1940, including night raids on London and other industrial centers that caused heavy civilian casualties and damage. The Royal Air Force (RAF) eventually defeated the Luftwaffe (German Air Force) in the Battle of Britain, and Hitler postponed his plans to invade. With Britain's defensive resources pushed to the limit, Prime Minister Winston Churchill began receiving crucial aid from the U.S. under the Lend-Lease Act, passed by Congress in early 1941.
With Britain facing Germany in Europe, the United States was the only nation capable of combating Japanese aggression, which by late 1941 included an expansion of its ongoing war with China and the seizure of European colonial holdings in the Far East. On December 7, 1941, 360 Japanese aircraft attacked the major U.S. naval base at Pearl Harbor in Hawaii, taking the Americans completely by surprise and claiming the lives of more than 2,300 troops. The attack on Pearl Harbor served to unify American public opinion in favor of entering World War II, and on December 8 Congress declared war on Japan with only one dissenting vote. Germany and the other Axis Powers promptly declared war on the United States.
On June 22, 1941, Hitler ordered the invasion of the Soviet Union, codenamed Operation Barbarossa. Though Soviet tanks and aircraft greatly outnumbered the Germans', their air technology was largely obsolete, and the impact of the surprise invasion helped Germans get within 200 miles of Moscow by mid-July. Arguments between Hitler and his commanders delayed the next German advance until October, when it was stalled by a Soviet counteroffensive and the onset of harsh winter weather
On June 6, 1944–celebrated as "D-Day"–the Allied began a massive invasion of Europe, landing 156,000 British, Canadian and American soldiers on the beaches of Normandy, France. In response, Hitler poured all the remaining strength of his army into Western Europe, ensuring Germany's defeat in the east. Soviet troops soon advanced into Poland, Czechoslovakia, Hungary and Romania, while Hitler gathered his forces to drive the Americans and British back from Germany in the Battle of the Bulge (December 1944-January 1945), the last major German offensive of the war. An intensive aerial bombardment in February 1945 preceded the Allied land invasion of Germany, and by the time Germany formally surrendered on May 8, Soviet forces had occupied much of the country. Hitler was already dead, having committed suicide on April 30 in his Berlin bunker.
World War II proved to be the most devastating international conflict in history, taking the lives of some 35 to 60 million people, including 6 million Jews who died at the hands of the Nazis. Millions more were injured, and still more lost their homes and property. The legacy of the war would include the spread of communism from the Soviet Union into eastern Europe as well as its eventual triumph in China, and the global shift in power from Europe to two rival superpowers–the United States and the Soviet Union–that would soon face off against each other in the Cold War.