I know Hitler was a huge asshole and psychopath who was responsible for the death of millions of people. He was an evil shitbag that deserves to die a billion painful deaths, but should we ever develop the ability to go back in time and find baby Hitler sleeping peacefully in his crib, we mustn’t give into the temptation to kill him in order to save the world from the pain and suffering he will cause (or caused, verb tense is really confusing when you’re talking about time travel).
Forget the fact that killing baby Hitler would have a ripple effect across time and could wipe out your own existence, which would create a time conundrum where the killer of baby Hitler never existed and therefore could have never gone back in time to kill baby Hitler, which means Hitler would have lived and gone on to become the genocidal maniac he was – or will be – or is. Essentially, meaning you would exist again, only to go back in time and kill baby Hitler, which would mean you never existed, which means baby Hitler would have lived – etc. and so forth and so on. In other words, there’s a high probability that you will create an endless time loop that will result in multiple streams of time where Hitler will commit the attempted genocide of the Jews and start Word War II over and over again, making you responsible for the death of not billions or trillions of people but an infinite number of people. Your crime against humanity would be far worse than Hitler’s because you’re his enabler.
As I said, forget that highly probable outcome. You shouldn’t kill Hitler because I love my family, and I’m assuming you do as well. You jeopardize their lives by taking out Hitler before he commits his atrocities. As awful and disgusting the things Hitler did are, preventing him from committing his evil destroys the present. The people we know and love won’t be the people we know and love. The world we live in now won’t be just dramatically different, it will be unrecognizable. I don’t know if it will be better or worse, but your parents, your sibling, your kids will not exist as they currently are. In fact, they may not exist at all. Do you want to put their existence at risk? Are you willing to make that kind of sacrifice for an unknown outcome? I’m certainly not.
Luckily, as I’ve said before, simple logic tells us that traveling back in time isn’t possible, so it will never be a decision any of us will have to make.