World War II was a global war that lasted from 1939 to 1945. It involved the majority of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis. It was the most widespread war in history, and directly involved more than 100 million people from more than 30 countries. In a state of "total war", the major participants threw their entire economic, industrial, and scientific capabilities behind the war effort, erasing the distinction between civilian and military resources. Marked by mass deaths of civilians, including the Holocaust (in which approximately 11 million people were killed) and the strategic bombing of industrial and population centers (in which approximately one million people were killed), it resulted in 50 million to over 70 million fatalities.
The war ended with the defeat of the Axis powers and the dissolution of their alliances. The United Nations (UN), formed in the aftermath of the war, and including many of the victorious powers, became the first international organization to address issues of global concern, including decolonization, human rights, and international security.
The causes of World War II are complex and have been the subject of much debate, but the primary factors that led to the outbreak of war were militarism, nationalism, and the aggressive foreign policies of Nazi Germany, led by dictator Adolf Hitler, and the Axis powers in Europe. The Treaty of Versailles, signed at the end of World War I, imposed severe penalties on Germany, including significant territorial losses and severe economic restrictions. Hitler, who came to power in 1933, used these grievances to fuel his expansionist policies and rebuild the military. He also pursued a policy of Aryan racial purity and sought to create a "new order" in Europe through the extermination of Jews, Romani, homosexuals, and other perceived "undesirables".
The Axis powers were opposed by the Allied powers, led by the United States, the United Kingdom, and the Soviet Union. The Allies fought a series of costly campaigns in Europe, North Africa, and the Pacific, ultimately leading to the defeat of the Axis powers and the liberation of the territories they had occupied. The war had a profound impact on the world, including the formation of the United Nations and the decolonization of many countries in Asia and Africa.
In conclusion, World War II was a devastating global conflict that resulted in millions of deaths and had a profound impact on the world. Its causes were complex and multifaceted, but ultimately it was the aggressive foreign policies of the Axis powers, particularly Nazi Germany, that led to the outbreak of war. The war ended with the defeat of the Axis powers and the establishment of the United Nations, which has played a key role in international relations and global security in the decades since.
