1. Germany Exercised More Patience Before Starting The War
A major reason why the Nazis lost the war is that they started a global military campaign before they were fully prepared for it. One shortcoming of this decision is that the German navy was poorly prepared to fight a war on the scale of World War II.
While the United States had aircraft carriers and several surface ships, German naval warfare relied mainly on U-boats. After World War I, the Treaty of Versailles prohibited Germany from amassing a large military force. The German navy and air force were not constituted until 1935.
Surprisingly, by 1939, Germany had already started war on a global scale. But Hitler only had about four years to prepare for it. If he had waited a decade longer, Germany would have had more time to develop a military force that could have won on such a large scale.