World War II

World War II
From top to bottom, left to right: German Stuka dive bombers on the Eastern Front, 1943 British Matilda II tanks during the North African campaign, 1941 U.S. atomic bombing of Nagasaki in Japan, 1945 Soviet troops at the Battle of Stalingrad, 1943 Soviet soldier raising a flag over the Reichstag after the Battle of Berlin, 1945 U.S. warships in Lingayen Gulf in the Philippines, 1945
Date 1 September 1939 – 2 September 1945[a] (6 years, 1 day) Location Major theaters: Europe Pacific Atlantic Indian Ocean South-East Asia China Japan Middle East Mediterranean North Africa Horn of Africa Central Africa Australia Caribbean North and South America Result Allied victory (see also Aftermath of World War II)
Participants
Allies	Axis
Commanders and leaders
Main Allied leaders: Joseph Stalin Franklin D. Roosevelt Winston Churchill Chiang Kai-shek	Main Axis leaders: Adolf Hitler Hirohito Benito Mussolini
Casualties and losses
Military dead: Over 16,000,000 Civilian dead: Over 45,000,000 Total dead: Over 61,000,000 (1937–1945) ...further details	Military dead: Over 8,000,000 Civilian dead: Over 4,000,000 Total dead: Over 12,000,000 (1937–1945) ...further details

World War II^[b] or the Second World War (1 September 1939 – 2 September 1945) was a global conflict between two alliances: the Allies and the Axis powers. Nearly all of the world's countries—including all the great powers—participated, and many invested all available economic, industrial, and scientific capabilities in pursuit of total war, blurring the distinction between military and civilian resources. Tanks and aircraft played major roles, with the latter enabling the strategic bombing of population centres and delivery of the only two nuclear weapons ever used in war. World War II was the deadliest conflict in history, resulting in 70 to 85 million fatalities, more than half of which were civilians. Millions died in genocides, including the Holocaust of European Jews, and by massacres, starvation, and disease. Following the Allied powers' victory, Germany, Austria, Japan, and Korea were occupied, and war crimes tribunals were conducted against German and Japanese leaders.

The causes of World War II included unresolved tensions in the aftermath of World War I, the rise of fascism in Europe, and Japanese militarism, and it was preceded by events including the Japanese invasion of Manchuria, Second Italo-Ethiopian War, Spanish Civil War, and Germany's rearmament and its annexations of Austria and the Sudetenland. World War II is generally considered to have begun on 1 September 1939, when Nazi Germany, under Adolf Hitler, invaded Poland. The United Kingdom and France declared war on Germany on 3 September. Under the Molotov–Ribbentrop Pact of August 1939, Germany and the Soviet Union had partitioned Poland and marked out their "spheres of influence" in Eastern Europe; in 1940, the Soviets annexed the Baltic states and parts of Finland and Romania. After the fall of France in June 1940, fighting continued primarily between Germany and the British Empire, with the onset of campaigns in North and East Africa and in the Balkans, the aerial Battle of Britain and the Blitz, and the naval Battle of the Atlantic. By mid-1941, following a series of campaigns and treaties, Germany conquered or controlled much of continental Europe and formed the Axis alliance with Italy, Japan, and other countries. In June 1941, Germany led the European Axis powers in an invasion of the Soviet Union, opening the Eastern Front.

Japan aimed to dominate East Asia and the Asia-Pacific, and by 1937 was at war with the Republic of China. In December 1941, Japan attacked American and British territories in Southeast Asia and the Central Pacific, including an attack on Pearl Harbor, which resulted in the United States and the United Kingdom declaring war against Japan. The European Axis powers declared war on the US in solidarity. Japan soon conquered much of the western Pacific, but its advances were halted in 1942 after its defeat in the naval Battle of Midway; Germany and Italy were defeated in North Africa and at Stalingrad in the Soviet Union. Key setbacks in 1943—including German defeats on the Eastern Front, the Allied invasions of Sicily and the Italian mainland, and Allied offensives in the Pacific—cost the Axis powers their initiative and forced them into strategic retreat on all fronts. In 1944, the Western Allies invaded German-occupied France at Normandy, while the Soviet Union regained its territorial losses and pushed Germany and its allies westward. In 1944 and 1945, Japan suffered reversals in mainland Asia, while the Allies crippled the Japanese Navy and captured key western Pacific islands. The war in Europe concluded with the liberation of German-occupied territories; the invasion of Germany by the Western Allies and the Soviet Union, culminating in the fall of Berlin to Soviet troops; Hitler's suicide; and the German unconditional surrender on 8 May 1945. Following the refusal of Japan to surrender on the terms of the Potsdam Declaration, the US dropped the first atomic bombs on Hiroshima on 6 August and Nagasaki on 9 August. Faced with imminent invasion of the Japanese archipelago, the possibility of more atomic bombings, and the Soviet declaration of war against Japan and its invasion of Manchuria, Japan announced its intention to surrender on 15 August and signed a surrender document on 2 September 1945, marking the end of the conflict.

World War II drastically changed the political, economic, and social structure of the world, and set the foundation of the international order for the rest of the 20th century and into the 21st century. The United Nations was established to foster international cooperation and prevent conflicts, with the victorious great powers—China, France, the Soviet Union, the UK, and the US—becoming the permanent members of its security council. The Soviet Union and the United States emerged as rival superpowers, setting the stage for the Cold War. Following Europe's devastation, the influence of its great powers waned, triggering the decolonisation of Africa and Asia. Most countries whose industries had been damaged moved towards a long period of economic recovery and expansion.
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