World War II: Causes, Key Events, and Global Impact

Following the First World War (1914-1918), the peace treaties signed between nations proved weak and unfair to some countries, leading to widespread discontent and a desire for revenge. The Treaty of Versailles significantly reduced the territories of Germany and Austria, including areas populated by Germans. Great ambition and rivalry arose between countries, especially those that had lost territory in the Great War.

The need to demonstrate military power to achieve a superior military and political position over other countries fueled tensions. Control and domination of certain areas were sought to exploit their natural wealth. Hitler envisioned a terrestrial version of England's maritime power.

Ethnic issues also played a significant role, particularly Hitler's philosophy regarding the purity of the "Aryan race," as expressed in "Mein Kampf." Three opposing ideologies clashed: liberalism, capitalism, the socialist system, and the Nazi-fascist ideology, the latter emerging in response to the totalitarian systems in Italy and Germany after World War I.

The Hitler government aimed to acquire a vast empire to provide new "living space" (Lebensraum) in Eastern Europe. Hitler believed that achieving German hegemony in Europe would require war. After securing the neutrality of the Soviet Union with the non-aggression pact, Germany initiated World War II by invading Poland on September 1, 1939. Britain and France responded by declaring war on Germany on September 3.

On April 9, 1940, German forces invaded Norway and Denmark. In May 1940, Germany launched its assault on Western Europe. The Soviet Union occupied the Baltic states in June 1940 and annexed them in August 1940. Italy, a member of the Axis, entered the war in June 1940. From August 13 to October 31, 1940, the Nazi air force attacked England in the Battle of Britain.

After dominating the Balkans with the invasion of Yugoslavia and Greece on April 6, 1941, Germany invaded the Soviet Union on June 22, 1941, violating the German-Soviet pact. In June and July 1941, the Germans also occupied the Baltic states. Stalin, the Soviet leader, became a key figure in the Allied group, alongside U.S. President Franklin Delano Roosevelt and British Prime Minister Winston Churchill.

On December 7, 1941, Japan (another Axis power) bombed Pearl Harbor, Hawaii. The United States immediately declared war on Japan. On December 11, Germany and Italy declared war on the United States.

Beginning in 1942 with the arrival of American troops in North Africa, the Allies achieved several military victories. On February 2, 1943, the German 6th Army surrendered to the Soviets at Stalingrad. In September, the Allies invaded Italy, which surrendered on September 8. However, Mussolini established a fascist regime in northern Italy. German forces then invaded northern Italy and moved south to confront the Allied forces. German troops remained in northern Italy until May 1945.

On June 6, 1944 (D-Day), two hundred fifty thousand Allied troops landed in France, which was liberated by the end of August. Allied air forces attacked Nazi industrial factories, including the Auschwitz camp (though the gas chambers were never targeted). The Soviets launched an offensive on January 12, 1945, liberating Poland and Hungary. In mid-February 1945, the Allies bombed Dresden, resulting in the deaths of nearly a hundred thousand civilians.

On April 29, Hitler committed suicide. Berlin was captured by Soviet forces in May 1945, and the Germans surrendered on May 7, 1945. In August, the war in the Pacific ended shortly after the U.S. used atomic bombs on Hiroshima and Nagasaki, instantly killing one hundred and twenty thousand civilians. Japan formally surrendered on September 2. The Second World War resulted in approximately 55 million deaths worldwide.