Overview of the Start and End of World War II
World War II began on September 1, 1939, when Nazi Germany, led by Adolf Hitler, invaded Poland, prompting declarations of war from France and the United Kingdom. The war ended on September 2, 1945, with the unconditional surrender of Japan following the atomic bombings of Hiroshima and Nagasaki by the United States, after Germany's surrender on May 8, 1945.
Key Causes and Phases of the Conflict
The war's origins stemmed from the Treaty of Versailles' harsh terms after World War I, economic instability, and aggressive expansionism by the Axis powers—Germany, Italy, and Japan. It unfolded in phases: the European theater from 1939–1941, the Pacific theater starting with Japan's 1941 attack on Pearl Harbor, and a global escalation involving the Allies (U.S., Soviet Union, UK, and others) until Allied victories in key battles like Stalingrad and Normandy.
A Pivotal Example: The Invasion of Poland and D-Day
The German invasion of Poland exemplified blitzkrieg tactics, using rapid armored assaults to overrun defenses in weeks, drawing in Allied forces. Conversely, D-Day on June 6, 1944, illustrated Allied strategy as over 156,000 troops landed on Normandy beaches, marking the beginning of the liberation of Western Europe and a turning point toward victory.
Global Impact and Legacy
World War II reshaped international relations, leading to the formation of the United Nations, the division of Europe into Cold War blocs, and decolonization movements. It caused an estimated 70–85 million deaths, including the Holocaust, and established principles of human rights and collective security that influence modern geopolitics.