A war that comprised of
two alliances (the Axis and the Allies) that went on from 1939 to 1945. The main cause of the war was the German invasion of Poland, which caused Great Britain and
France to declare war on
Germany. Germany used a strategy called "Blitzkrieg" or in English terms, "Lightning War" to swiftly take out the
French. Before the invasion of Poland, the Germans and Soviets signed the Molotov-Ribbentrop pact, which was a nonaggression pact which also agreed to
split poland between the
two nations. This pact would be broken in a few years in what became Operation Barbarossa, the German invasion of the Soviet Union. After these events, the Japanese bombed Pearl Harbor, which led the United States of America to declare war on Japan. Germany declared war on the US as well. Years later, after many battles and
air superiority, the Allies launched a mass invasion of Normandy of what is called D-
Day. This invasion led to the fall of Germany the year after, when the Soviets took Berlin and when Adolf
Hitler killed himself in a bunker underneath Berlin. America then used atomic bombs on Hiroshima and Nagasaki in which the Japanese surrendered after that. Thus, ended the second world war.