Martin Reast has written a book in which he gives the human species a 50% chance of making it through this century, the 21st century. He's worried about massively powerful weapons falling into the hands of terrorists. The principle of deterrence presupposes that everybody wants the world to live and go on. Now we've got people who, for religious reasons, want to die. And so if they got their hands on a biological weapon, the normal deterrence might not apply. But going forward again, the people, like you said, the genes that will go for are the ones who have the most children.