The Second World War began with Hitler's attack on Poland in 1939 and ended with the atomic bomb on Hiroshima in 1945. During these six years many battles were fought in both the European and Pacific theatre that led to the success of the Allies and to the collapse of the Axis Powers.
In the European theatre, America and its allies (Britain, France and Soviet Union) adopted a "Defeat Hitler first" strategy. In the eastern front, the Russians won a victory against the Germans who had vainly tried to capture Stalingrad since August 1942. Despite the seige ,the Russian troops refused to budge and defended successfully. In November, Russian reinforcements trapped the Germans who were then forced to surrender. This was an important battle because if Stalingard had been captured by the Germans, the Russian oil route would have been cut off. It was from this point on that the Russians started to drive the Germans out of the Soviet Union and it was now clear, probably to even Hitler himself, that the war was definitively lost.
In the west, the Allies launched an invasion code named D-Day on German occupied France from the beaches of Normandy. By late August the Allies had liberated Paris and they now advanced towards Berlin. Hitler launched a final attempt to stop the Allies in December 1944, known as the Battle of the Bulge. He risked everything on the attack, however it only slowed the Allied advance by three weeks. With the Allied forces pushing the Germans east as the Soviet Union pushed German troops west the two sides met and Berlin fell to Stalin's forces.
In the Pacific theatre, the Japanese were conflicting with US rights and interests. With Europe in war, Japan invaded China and spheres of influences of other countries as...