I had a professor in college show a picture of Hitler holding two small children before he took power. He asked if you could go back in time and stop Hitler from taking power by killing him and the two children, would you? There were some that said no because the kids were innocent and they did nothing to deserve being killed. I took the position, as did several others, that if the two kids dying were the price of keeping millions alive, then it was a small price to pay.