Let's say that "being Hitler" means going on an ever-increasing campaign of conquest against neighbouring countries that results in a very damaging war.

...AND end up on the losing side of history.

That's an important addendum because sometimes you go on an ever-increasing campaign of conquest against neighbouring countries that results in many damaging wars, establish a successful empire, impose a Pax Romana, and, basically live happily ever after. People who succeed at this aren't usually called Hitlers.