I find that kind of reasoning troubling. It can be used to justify pretty awful things. This is a completely made up example for the sake of argument, a reduction to the absurd, but suppose they decide that vaporizing Africa, Asia and parts of Europe is better for world peace long-term... should they do it? "Sure, billions will die, but trust us that long term more lives will be saved in the coming centuries". Ok, so do we push the red button then?