Why did the Nazi empire fall

Jewish allies defeated the Germans.

The Nazi Empire fell when Germany surrendered in May 1945. Adolf Hitler had committed s u i c i d e about a week before Germany surrendered to the Allies.

Explanation:

It took the largest war in human history to bring about the downfall of Nazism. The invasion of Poland in September 1939 was not intended to provoke a major war. In Hitler's mind, it was another act of expansion, much like the Anschluss with Austria and the Nazi incursion into Czechoslovakia. Hitler believed the British were unwilling to initiate another war and that London would instead seek a second agreement.