I'm reminded of the scene in the movie "The Dead Zone" (I nicked this quote from IMDB)
Johnny Smith: [John has "seen" Stillson become President and trigger WW3, and now is making up his mind how to prevent Stillson's holocaust] If you could go back in time to Germany, before Hitler came to power, knowing what you know now, would you kill him? Johnny Smith: What about my question? Dr. Sam Weizak: Huh? Huh? Oh, you mean the one about Hitler? Johnny Smith: What would you do? Dr. Sam Weizak: I don't like this, John. What are you getting at? Johnny Smith: What would you do? Would you kill him? Dr. Sam Weizak: All right. All right. I'll give you an answer. I'm a man of medicine. I'm expected to save lives and ease suffering. I love people. Therefore, I would have no choice but to kill the son of a bitch. Johnny Smith: You'd never get away alive. Dr. Sam Weizak: It doesn't matter. I would kill him.