Assassins can’t be held responsible for the random consequences of succession. If they had their way there wouldn’t be a succession.

Otherwise why not blame everyone for NOT assassinating someone like Hitler early when they had the chance?

The justification for assassination is almost always going to have to rest on Consequentialist grounds, since it’s literally killing someone without a trial for political reasons.  There WILL be a succession, so you can’t credibly claim ignorance of the fact that there would be one, and it doesn’t matter if they assassin doesn’t want one unless they can stop that succession too..  The assassin has made a choice, and they went into it knowing that they wouldn’t know all the consequences.

This is killing a head of state, or former head of state.  This isn’t like some small accident resulting in a gas leak explosion you could never have anticipated.  It’s going to have big consequences.

Also, there were, in fact, multiple attempts to assassinate Hitler.

@ranma-official is in the right on this one.  

I mean look, I like states.  I think they’re better than whatever Anarchists will cook up.  But states are fundamentally grounded in geopolitical realities based on the threat of force, in a world where multiple actors are willing to use force and you don’t know for sure whether they will.  Your information is always imperfect, and if you fuck up, the end result could be global thermonuclear war.  

It’s very difficult to walk out of that situation without any blood at all if you’re an ordinary human.

That doesn’t excuse Bush, but I think if you became the leader of a nation you’d take some course of action justifying the assassination of you based on your own criteria.