World War II

World War II is the worldwide conflict from 1939 to 1945, including the hostilities involving Japan starting in 1937.

By the end in 1945, nearly every nation was involved. This war, more than any other, propelled nations towards total war, a complete social, political, military, and economic commitment of a nation to war. Thus the war stimulated unprecedented levels of productivity and generated a wide variety of new technologies. The nations had been mobilized in the interests of many opposing ideologies, often seeking the unconditional surrender of their enemies. As whole populations were materially and politically, if not militarily, invested in the war effort, the distinction between combatant and non-combatant became blurred. Furthermore, many of these ideologies preached ideas of racism and genocide. Thus the level of civilian causalities in this war far surpasses any other in human history.

This war also marks the end of European domination of the globe and the rise of a bi-polar world dominated by the superpowers United States and the Soviet Union. The war also broke the ability of the remaining colonial powers (mainly Great Britain, France, Japan, and the Netherlands) to hold and maintain their empires. Thus the war also sparked a period of decolonization afterward.

In the Commonwealth nations, official histories of the war use the term Second World War. This style also follows literaly translations of other nations' official designation for the conflict, e.g. Zweiter Weltkrieg in German. The official histories of the United States refer to the conflict as World War II or World War Two, and that term is now often used in Canada and the UK as well.

Parts of the world, especially Latin America, were largely unaffected directly by the conflict, with significant concentrations of activity in the European, north African, Russian, and Pacific theatres.

Allied theater designations

Causes and Diplomacy

American logistics

Europe

Poland

Allied strategy and supply lines

Both Germany and the Soviet Union participated in an armed invasion and occupation of Poland, beginning with an initial German attack on September 1, 1939. The German invasion has often been referred to as "blitzkrieg" (lighting war), due to the close coupling of tank-heavy armored forces with close air support, under common radio direction, with foot-mobile infantry following up to secure the breaches.

France and Great Britain, having sworn to defend Poland, declared war on Germany but in the end were unable to provide material assistance. The Soviet Union launched its own invasion of Polish territory, and Slovak troops also participated in operations on Polish soil. Poland officially capitulated in October.

Western Front

Phony War

Invasion of Norway

Battle for France and the Low Countries

Battle of Britain

Battle of the Atlantic

Invasion of Normandy

D-Day landings

Northwest Europe Campaign

Southern France

Crossing the Rhine

Mediterranean Front

Invasion of Greece

Invasion of Yugoslavia

North Africa

Battle of Sicily

Operation Husky: Invasion of Sicily, 1943

Italian Campaign

Invasion of Italy 1943

Eastern Front

Winter War

Operation Barbarossa

Continuation War

Battle of Berlin

Asia

see World War II in the Pacific

China, Burma, and India

see CBI

Second Sino-Japanese War

Japanese expansion in the Pacific

Battle of Pearl Harbor

Battle of Midway

Battle of Coral Sea

Battle of Guadalcanal

Defeat of the Japanese Empire

Battle of the Philippine Sea

Battle of Leyte Gulf

Battle of Iwo Jima

Battle of Okinawa

Naval Warfare

Major developments

On December 7, 1941, the battleship, with large guns as its primary weapon, had become secondary to the aircraft carrier as the dominant ship of the world's navies. The last combat between battleships was the Battle of Surigao Strait on 25 October 1944.

Naval aviation, primarily carrier-based but with some significant activity by land-based aircraft, became the centerpiece of combat at sea, although submarines, primarily operating alone, was also decisive. Defense against aircraft attack also advanced quickly, with the key technologies of radar, improved anti-aircraft artillery with proximity-fuzed shells, combat air patrol doctrine, and combat information center coordination. Defense was especially important against the first large-scale use of precision-guided munitions, or kamikaze aircraft with pilots intending to die with their airplanes crashing into ships.

Amphibious warfare doctrine and practice constantly improved.

replenishment at sea allowed U.S. fleets to operate for long periods, away from bases. This was a major force multiplier.

Air War

see World War II, air war

Results and Aftermath

Japan

Total Japanese military fatalities between 1937 and 1945 were 2.1 million; most came in the last year of the war. Starvation or malnutrition-re­lated illness accounted for roughly 80 percent of Japanese military deaths in the Philippines, and 50 percent of military fatalities in China. The aerial bombing of a total of 65 Japanese cities appears to have taken a minimum of 400,000 and possibly closer to 600,000 civlian lives (over 100,000 in Tokyo alone, over 200,000 in Hiroshima and Nagasaki combined, and 80,000-150,000 civilian deaths in the battle of Okina­wa). Civilian death among settlers who died attempting to re­turn to Japan from Manchuria in the winter of 1945 were probably around 100,000.