World War II was a global military conflict that,
in terms of lives lost and material destruction, was the most devastating war
in human history. It began in 1939 as a European conflict between Germany and
an Anglo-French coalition but eventually widened to include most of the nations
of the world. It ended in 1945, leaving a new world order dominated by the
United States and the Union of Soviet Socialist Republics (USSR).
More than any previous war, World War II involved
the commitment of nations’ entire human and economic resources, the blurring of
the distinction between combatant and noncombatant, and the expansion of the
battlefield to include all of the enemy’s territory. The most important
determinants of its outcome were industrial capacity and personnel. In the last
stages of the war, two radically new weapons were introduced: the long-range
rocket and the atomic bomb. In the main, however, the war was fought with the
same or improved weapons of the types used in World War I (1914-1918). The
greatest advances were in aircraft and tanks.