So show me where I'm wrong.
In 1938 Germany's military was out manned, out gunned, and out equipped. The reason they won during 1939/1940 was due to brilliant leadership, excellent training, and superior morale with a desire to win. They didn't win due to superior firepower, man power, or equipment.
The Allies didn't have the stomach or desire for a fight. The Allies' lack of will was the German's greatest weapon. It's the same today, which is exactly what Iran and the other Islamists are counting on to win.