Saving Hitler

A time traveler from another dimension killed Adolph Hitler. His actions created an alternate time stream that will lead to a modern world dominated by Communism.
And the nukes are all pointed at the United States?

But the time traveler lost his time machine and when it's found eighty years later with details of what he's done to the universe, amends must be made to avoid nuclear annihilation.
Jack Mayberry is tasked with going back in time to save Adolph Hitler's life before his own world ends, but can he bring himself to save a man who will go on to kill millions?