Hiroshima after the U.S. dropped the atomic bomb
in August 1945
About twenty years after the end of World War I, global war once again broke out. This time it was bigger, covered almost every continent, and ended up with huge casualties that threatened the annihilation of certain populations.
The major theaters of conflict included Africa, Europe, Asia, and the Pacific Islands, although North America saw action as well. Hitler began World War II in September 1939 by invading the western half of Poland. The Soviet Union invaded the eastern shortly thereafter. After the Soviets invaded the Baltic states followed by Finland, Germany invaded Denmark and then Norway. Hitler then turned to France in May 1940, defeating the country in two weeks. Germany then began the Battle of Britain, the aerial bombardment of Britain which was under the leadership of a new Prime Minister, Winston Churchill. Despite inflicting heavy damage, the Germans were unable to make significant headway, and soon gave up the assault. Hitler turned his forces against his Soviet allies with the largest land assault in military history. The Soviet Union eventually held their ground against Germany at Stalingrad and forced the German soldiers to start retreating.
At the same time, the Allies planned their attack in North Africa under the leadership of George C. Marshall, the U.S. Army Chief of Staff. The Allies defeated the Axis powers at the Battle of El-Alamein, Egypt and then moved northwards to liberate parts of Italy. In June 1944, the Allies opened a second front in Europe during the D-Day invasions led by U.S. General Eisenhower. As the Allied troops landed in France, the Germans were forced to slowly retreat. Germany did try one last offensive at the Battle of the Bulge, but the Allies finally forced Germany to surrender on May, 7 1945.
On the Pacific front, Japan had invaded Manchuria and China during the 1930s. When the U.S. instituted a trade embargo on particular resources that were vital to the Japanese war effort against China, Japan bombed Pearl Harbor on December 7, 1941.
President Roosevelt asked Congress to declare war against Japan the next day, and the United States officially entered World War II. Japan was led by the Emperor Hirohito and the Prime Minister Hideki Tojo, a military officer. The United States, led by General Douglas MacArthur, fought the majority of the battles for the Allied powers in the Pacific theater. America's island-hopping campaign was a strategy where the U.S. liberated different Pacific islands in order to get close enough to attack the Japanese mainland. The turning point in the Pacific was the Battle of Midway in June 1942. The Japanese military put up fierce fights at Iwo Jima and Okinawa. Harry S Truman replaced Roosevelt after his death in April 1945 and made the decision to drop atomic bombs on both Hiroshima and Nagasaki in August 1945. Shortly thereafter, Japan officially surrendered.