At the start of the war, Germany was by far the most militarily advanced nation on earth. At the end, they were beaten. How? Why? The cause can simply be attributed to Hitler, who besides being a sadistic bastard, was also a complete moron when it came to running either a country or a military.
Basically, WW2 would have been wrapped up were it not for his mistakes. Let me see if I remember some:
1) Allowing allied forces to escape the European mainland. He held back the ground forces to allow the Nazi-led air force take out the enemy. Unfortunately, the luftwaffe failed in its mission.
2) Battle of Britain: this wads started after a few British planes bombed a German city. Hitler grew so upset that he halted the bombing of British military infrastructure in favor of civialian, non-military targets.
3) Refusal to go to a wartime economy: Its always a bad thing when you need to build all the tanks you =can and still insist on building toasters.
4) Delay of the invasion of Russia. Speaks for itself.
5) The holding of the Russian frontier: Hitler would not allow his troops in russia to withdraw an inch, even if this meant gaining better defensive position for the winter.
6) And of course, the biggie, Hitler takes control of the army, replacing his generals.
Here are some things you may not have heard:
It is believed that German scientists refused to finish their work on the nuclear bomb because of the results they expected should Hitler get his hands on such a weapon. The step from where they were to the final product was apparently trivial.
Germany, towards the end of the war, had plans for a massive bomber. One test model was built, and it was flown to within 10 miles of New York City before it turned around. This was to show that the US could be reached; it was not invulnurable. The plane never went into pruduction, it was already too late.
Another weapon designed against the American threat was the first ICBM, with a range of over 2000 miles. It, unlike its smaller cousin the V2, was never put into production.
These latter two items were hindered by Hitler's refusal to go to a wartime economy.
Marty