Nuclear endgame: The growing appeal of zero
economist.com
economist.com
The problem is that Libya consented not to have nuclear weapons. Now everyone does what they want with Libya.
Nuclear weapons do work as a deterrent, but small countries profit orders of magnitude more from this than big ones, which are hard to attack anyway. That small countries are able to defend themselves against the US is the main reason for the US to exert so much pressure against "proliferation".
Politicians know that; that is why they threaten the nuclear card when they can, even though I think most wouldn't dare play it.
The US would not chance a nuclear retaliation either. If they had not been sure that Iraq does _not_ possess nuclear weapons, they would never have invaded.