Even the very wise cannot see all ends.

Hitler lost the war because he made certain key mistakes -- chasing his country's best scientists out, invading Russia at the wrong time, spending a fortune on gimmicks to murder civilians instead of combat weapons. It's possible that killing Hitler would have paved the way for a more competent, saner leader to emerge.

> It's possible that killing Hitler would have paved the way for a more competent, saner leader to emerge.

only an insane leader would have invaded france from the belgian ardennes; from your logic, ww2 would have been avoided