World War II

The Second World War (World War II or WWII) was a global military conflict, which arose as a result of Germany's invasion of Poland in 1939, and later merged with the Second Sino-Japanese War which began in 1937.

The conflict split the majority of the world's countries into two opposing alliances: the Allies (Great Britain, France, Soviet Union, United States) and the Axis powers (Germany, Italy, Japan).

It involved the mobilization of over 100 million military personnel, making it the most widespread war in history, and placed the participants in a state of "total war", erasing the distinction between civil and military resources.

The result of the war was a victory for the Allies, with the United States and Soviet Union emerging as the new world superpowers, which set the stage for the Cold War. African countries moved faster towards decolonalisation, and Europe headed for more cooperation and integration. However, it was the European participants that were forced to recover from the worst effects of the war, with severely depleted populations, resources (military and civil) and ruined cities from bombing raids.

Over 60 million people were killed, mostly civilians, making WWII the deadliest conflict in human history. The financial cost of the war is estimated at about a trillion 1944 U.S. dollars worldwide, making it the most costly war. The United Nations was established to prevent another war such as this.

Technology
Like the First World War, one of the results of WWII was the massive enhancement in military technology. Air warfare became very important for the first time, with military leaders opting for mass arial bombing rather than slow, dangerous trench battles. Tanks became fast and light, to be efficient in mechanised battles rather than trench warfare. The United States also created the first amphibious vehicles in 1941. The first military helicopters came into operation during WWII.

In the Sea, Aircraft Carriers became the most important vessel in a fleet. High-tech Submarines came into use, destroying vital shipping links and prompting a range of anti-submarine defences such as SONAR.

Weapons developed during the war included Rocket Propelled Grenades (RPGs), the first Cruise Missile, a wide range of air bombs, Napalm and plastic explosives such as C2. Handheld weapons increased in variety, reliability and accuraccy, including the first Assault Rifles. The most destructive creations were the first Atomic Bombs.

Technology for communications and intelligence rose to increased significance, with the development of Radar, SONAR, encryption technology (such as the Enigma machines) and the Magnetron (now used in microwave ovens) all coming to prominence. However, the war slowed down the development of nonessential technology such as radio and television.

One of the most dramatic single medical advance was probably the wide spread use of penicillin to treat wounds and bacterial diseases.