Assassinate Hitler?

If he was actively seeking to implement his policies at that time, then yes.

Hmmm....please explain.

Skiguy, I agree more with your line of thinking than with Donnie's or Stumpfoot's.  Perhaps I should have avoided the “assassination” issue here, but even setting that aside, I don't think it's right to punish someone for future evil acts which have not occurred.  By the way, I think this is a classic ethical question which you may already have heard.  It's a good question to ponder, though.

I think that the crux of the ethical matter, though, is that you cannot harm someone for evil not yet decided upon, not yet committed or in the act of committing.  In this sense the question echoes the situation present in the movie Minority Report, where people were arrested for crimes not yet performed.  Because Hitler hadn't begun his reign of terror in the 1920s we can't punish him for acts he'll decide to do later on in life. 

So then if you answer “yes” you should have no problem if someone were to come back in time and assassinate you for a disastrous evil act committed by you at some point in the future, even if you haven't decided to do this act yet….right?  And it's my understanding that the Allies did not know the extent of the holocaust until they freed the prisoners.  I'm sure they may have had "reports" but not the pictures we know of now through history books, movies, etc.

But ski I think that's the whole point of the question, at least from an ethics perspective.  It's my understanding that it would not be right to kill Hitler back in the 1920s or so even if you knew the atrocities he would commit later on in life.  Because he had not yet done these atrocities you can't punish him, even if you know he was going to do them later on.  Perhaps a better way to look at the situation is like this – statistics will say whether or not a particular person has a good chance of committing crime given the environment the person grows up in.  Would it be alright to kill that person before the person actually committed any crime?I remember hearing the Hitler scenario from a person some years ago and thinking that it would be permissible to kill him to prevent later horrors.  However, the person asking the question said it would not be correct.  Whatever the result, it's an interesting ethical decision to ponder.