It Only Has To Happen Once

In his new book, The Ancestor's Tale, Richard Dawkins discusses the possible migration of monkeys from Africa to South America on floating mangroves, noting that, "It only had to happen once." He goes on to make the following, frightening observation:

The principle of nuclear deterrence, and the only remotely definsible
justification for possessing nuclear weapons, is that nobody will dare risk a
first strike, for fear of massive retaqliation. What are the odds against a
mistaken missle launch: a dictator who goe4s made; a computer system that
malfunctions; an escalation of threats that gets out of hand? The present leader
of the largest nuclear power in the world (I am writing in 2003) thinks the word
is 'nucular'. He has never given any reason to suggest that his wisdom or his
intelligence3 outperforms his literacy. He has demonstrated a predilection for
'pre-empive' first strikes. What are the odds against a terrible mistake,
initiating Armageddon? A hundred to one against, within any one year? I would be
more pessimistic. We came awfully close in 1963, and that was with an
intelligent President. In any case, what might happen in Kashmir? Israel? Korea?
Even if the odds per year are as low as one in a hundred, a century is a very
short time, given the scale of the disaster we are talking about. It only has to
happen once.

No wonder Bush hates evolutionary scientists. They, too, have got him figgered out.