- World War II was a global war that lasted from 1939 to 1945.
- The war involved the vast majority of the world’s countries—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis.
- In a state of total war, directly involving more than 100 million personnel from more than 30 countries, the major participants threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources.
- World War II was the deadliest conflict in human history, marked by 50 to 85 million fatalities, most of whom were civilians in the Soviet Union and China. Tens of millions of people died due to genocides (including the Holocaust), premeditated death from starvation, massacres, and disease. Aircraft played a major role in the conflict, including in the strategic bombing of population centers, the development of nuclear weapons, and the only two uses of such in war.
The war in Europe began on September 1, 1939, when Germany invaded Poland. Great Britain and France declared war on Germany on September 3. The war in the Pacific began on December 7, 1941, when Japan attacked the American naval base at Pearl Harbor.
The war ended on September 2, 1945, when Japan surrendered after the United States dropped atomic bombs on Hiroshima and Nagasaki.
The causes of World War II are complex and still debated by historians. Some of the factors that contributed to the war include:
- The rise of fascism and Nazism in Europe
- The failure of the League of Nations to prevent aggression
- The economic depression of the 1930s
- The territorial ambitions of Germany, Japan, and Italy
The war had a profound impact on the world. It led to the deaths of millions of people, the destruction of cities and infrastructure, and the end of European colonialism. It also led to the development of new technologies, such as nuclear weapons, and the creation of the United Nations.
World War II was a watershed event in world history. It changed the course of the 20th century and had a lasting impact on the global order.
