World War II

World War II started on September 1, 1939 with the invasion of Poland by Germany. Throughout the six years it went on, eight major world powers fought in the war, along with several lesser states joining with one side or the other. On the side which lost were the Axis Powers Germany, Japan, and Italy. Against them were the Allied Powers Great Britain and the Commonwealth, Russia, France, China and later United States.

Causes

The causes of World War II are complicated. The immediate causes of World War II are generally held to be the German invasion of Poland, as well as the Japanese attacks on China, the United States, and the British and Dutch colonies. World War II began after these acts of aggression were met with an official declaration of war, armed resistance or both.

German tactics

The Germans implemented a tactic known as Blitzkrieg (translated: Lightning War) to rapidly overwhelm their targets. Blitzkrieg was a maneuver tactic where armored columns would break through the enemy lines, supported by artillery and attack aircraft. Once the columns were through the line, they would not stop but continue into the enemy rear, disrupting their supply lines and cutting off units. The armored columns were followed by infantry units that would exploit the gaps and surround the isolated enemy units. The tactic worked most effectively in Europe against the French and the Netherlands, and in the beginning of the conflict against the Soviet Union. It's success was due to a combination of surprise and favorable terrain.

There was three flaws to the Blitzkrieg tactic. First, it was heavily dependent on good weather and good terrain. If the terrain was hilly, combat was in an urban area, or if the weather turned the ground muddy (as in the Soviet Union), the armored units would slow down and become vulnerable to anti-tank units.

Second, air support was vital. Without it, the tanks were vulnerable to counter-attacks from enemy aircraft. As the war progressed and the Germans lost control of the air, their panzer units suffered heavy losses from Allied air-to-ground aircraft such as the Soviet IL-2 and American P-47 Thunderbolt.

Third, the blitzkrieg could be broken up by channeling the attack (holding the flanks) and attacking the point where the infantry and armored units met. This would separate the two and expose the armor to counter-attacks. The French and British used this tactic at the Battle of Arras in 1940, but lacked the armored units required to exploit their limited success.

The Soviets used all the above and had the additional fortune of vast swaths of land to design a defense-in-depth. As the panzer units moved further and further from their supplies, gaps would appear in their columns. These could then be attacked to break up the armor. Also, the Soviets used minefields to further disrupt the German armor.

By 1944, blitzkrieg as a German tactic was finished. The last actual appearance of blitzkrieg in the war was when General George S. Patton's Third Army broke out of the Normandy Pocket in Operation Cobra. The Allied columns covered 600 miles in just under two weeks.

The end of World War II in Asia

On August 6, 1945, a B-29 Superfortress, the Enola Gay, dropped a nuclear bomb on Hiroshima. Then, on August 9, a B-29 dropped the second atomic bomb. On August 20 the Japanese government told the United States they were ready to accept the terms which the Allies proposed. The next day, the Allies replied, saying the authority of the emperor would be "subject to the Supreme Commander of the Allied Powers." On August 14 the Japanese government agreed to this.

Then, September 2, 1945, the Japanese government, along with all it's military forces, formally surrendered to the United States. This happened in a ceremony aboard an American battleship, the Missouri, on Tokyo Bay, where the Japanese Instrument of Surrender was signed. This was the ending of World War II, after six years almost to the day.