On 7 December 1941, Japanese naval and air forces attacked the
American Pacific Fleet base at Pearl Harbor on the Hawaiian
island of Oahu. No declaration of war was made. The attack was
one of the most important events of the twentieth century.
brought the United States of America into the Second World War
and, together with the German assault on the Soviet Union in
June 1941 and Hitler's declaration of war on America on 11
December, turned a series of regional campaigns into a true
world conflict. Although two mighty alliances now faced each
other, the addition of America's vast industrial power to
their cause virtually assured the eventual victory of the USA,
Britain and the Soviet Union.