When did World War 2 officially begin?
Since the Second World War involved most of the world's nations different combatants entered the war at different points. However, it is generally agreed that the war started on September 1, 1939 with the German invasion of Poland. (Please note that some combatants such as the Japanese had already been fighting in China since 1933.)
For the United States, WW2 officially began on December 7, 1941. In Asia, WW2 began in 1931, 1933, or 1937, depending upon which book you are reading. The war in Europe began in 1939. Under Great Britain's urging, historians have accepted Britain's definition for the beginning of WW2; September 1, 1939.
World War 1 started in 1914 and ended in 1918. World War II, was the amalgamation of what had initially been two separate conflicts. The first began in Asia in 1937 as the Second Sino-Japanese War; the other began in Europe in 1939 with the German invasion of Poland, however World War 2 officially started on September 1, 1939.
Russia and Japan are officially still at war, and they have been since war was declared in the Second World War. However there hasn't been any military engagements between them since World War 2 ended. Russia and Japan refuse to sign a treaty ending the hostilities between them because of a territorial dispute over the Kuril Islands.
America remained isolated during World War 2 for about two and a half years. They began having a bad relationship with Japan. All of a sudden on a bright morning on December, 7, 1941, planes begin crashing into Pearl Harbor(Hawaii). These were kamikazes-Japanese suicide pilots, who carried the plans out. Then on December 8, 1941, Congress declared war on Japan. The U.S. has officially entered World War 2 dealing with the conflict in Europe and…