Hitler did actually try and write another book. Its been called Zweites Buch or "Second Book", where as Mein Kampf focused on Hitler's early life and struggles as well as setting the tone for Nazi racial politics, the Second Book focused on foreign policy and what the Nazis plans were for their neighbours. The book sets out step by step what the Nazi's plans were and how they planned to accomplish them. It talks about the alliance with Italy, the alliance with Great Britain that Hitler hoped would happen, and the plans to deal with the Soviet Union. The book deviates near the end and goes into a sort of alternate history, where Hitler talks about the future of the Nazi state and what will most likely happen when the Nazis achieve total domination of Europe. Hitler envisions that a German dominated Europe and the British Empire will fight an almost cold war like struggle against the United States.

The book was written in 1928 after Mein Kampf, but it was never published for two reasons. One, mein kampf flopped and thus Hitler never bothered publishing his second work. And two, the Nazis were strapped for cash and Hitler was told to hold off from releasing another book, lest he spoil the market and alienate the few people who were buying his books. Historian Gerhard Weinberg would later publish the unreleased book in his own book called "Hitler's Second Book: The Unpublished Sequel to Mein Kampf". I find that today, most copies of Mein Kampf will include both books together, because they really are meant to go together.

In Albert Speer's memoirs he says this about Hitler when he was chancellor.

"Politics, for Hitler, was purely pragmatic, He did not except his own book of confessions and professions, Mein Kampf, from this general rule. Large parts of it were no longer valid, he said. He should not have let himself be pinned down to definite statements so early"