In Mein Kampf, Hitler expressed the belief that Germans were destined to lead the world. This idea of German superiority and destiny to dominate other nations was a central theme in Hitler's ideology. He believed in the concept of "Lebensraum" or living space, which justified German expansion and conquest to secure resources and establish dominance. Hitler's vision was centered around the idea of a racially pure and powerful German nation that would lead the world to greatness. This belief in German supremacy and destiny to lead played a significant role in shaping his policies and actions during World War II.