I used to think that folks like N. Korea, Iran, et al. were only developing nuclear weapons to join the big boys on the world stage (or at least extort them). Because they weren’t really interested in blowing us up, we didn’t have as much to worry about. I still think we shouldn’t let them go nuclear, but that doesn’t mean we have to invade. Before 2002, an airstrike against their nuclear facilities would have seemed appropriate and probably been enough because of the threat of invasion as a last resort.
Now, I think that the Iraq war has changed everything. Since we can’t seem to win in Iraq, we either face:
a) a country that builds a nuclear weapon and thinks that we won’t do anything about it because we don’t have the guts or the strength to get involved in another Iraq
b) a country that uses a nuclear weapon because they think that America won’t have the guts or the strength to get involved in another Iraq
In the second situation, we could probably rally enough world involvement to win the war. (Provided we don’t invade Cuba because N. Korea nuked us.) But the question is, have we created a world where other countries might bet on our unwillingness to invade?