Though there were several contributing factors, the main one was the German invasion of Poland.
Pearl Harbor is the event that made them declare war.
bombing of pearl harbour.
pearl harbour!
Germany was TOO imperialistic, and they forced Britain into the war.
Which event at the conclusion of World War 2 initiated the Cold War?Read more: Which_event_at_the_conclusion_of_World_War_2_initiated_the_Cold_War
World War 2
world war 2
World War 2
world war 2
The Iraq War.
War is a social event.
Most historians agree that the German invasion of Poland on September 1, 1939, was the event that marked the start of World War 2.