In August of 1939 Germany invaded Poland after invading Czechoslovakia and being told not to invade anyone else. Germany still invaded Poland after going against what he said they wouldn't do. Germany violated the nonaggression rule and many countries got mad at them.
On September 3rd, a few days after Germany invaded Poland France and Britain declared war on Germany. They did this because they were angry because Germany didn't follow there nonaggression rule and if they didn't stop Germany they would continue to invade places.
On December 7 1941, Japan bombed US soldiers at Pearl Harbor without warning. This made the US officially get involved in the War.
Two Atomic Bomb are Dropped on Japan
On June 6th of 1941 the Allies invaded France to help them. Germany was in France and the Allies tried to get them out. They did successfully and it was a turning point in the war.
On April 24th, the Russians took Berlin away from Germany which was a major city. Germany's fall came after this and they surrendered.
We give up!
On august 6th and August 9th, 1945 America dropped atomic bombs on Japan sipping out a large amount of their population. This caused Japan, the last major force of Axis Powers, to surrender marking the end of World War Two.