We were talking about mutual assured destruction (MAD) the other day, and the thought just occurred to me. Can MAD be used to argue for nuclear proliferation?
I mean, the whole theory rests of the fear of retaliation from the other country, and that no matter what the offending country does, it cannot completely destroy its enemy's ability to strike back. For the defending country, this means it needs to ensure its weapons will not be easily destroyed. And what easier way to do this than to make multiple nuclear warheads, and hide them in different places around the country? The larger the nuclear arsenal, the larger the threat of retaliation, the more MAD applies.
As for actual proliferation, countries without nuclear weapons will feel insecure against countries with nuclear power, and therefore will want to have nuclear weapons.
Of course, that's the equivalent of having a nuclear arms war, but MAD doesn't say anything about that. In the words of one of my design books, the safety in MAD is only circumstantial to the situation, but not inherent. It is in some sense a dynamic equilibrium; only when both countries have nuclear warheads will MAD work.
Which, to be honest, makes MAD look a little, well, mad.