As has been the case with every nation that went nuclear, possession of such weapons is seen by the North's regime as a strategic necessity. That's why decades of pleading with and punishing the North simply haven't worked.

Developing a credible nuclear force is in the long run cheaper for Pyongyang and far more likely to be successful than building and maintaining the massive and highly sophisticated conventional forces that would be needed to deter the United States.

Pyongyang's self-defense claim is also hardly extraordinary. It has been used by all of the nuclear powers.

"The Saddam Hussein regime in Iraq and the Gadhafi regime in Libya could not escape the fate of destruction after being deprived of their foundations for nuclear development and giving up nuclear programs of their own accord, yielding to the pressure of the U.S. and the West keen on their regime changes," the Korean Central News Agency said in a commentary.

If, as North Korea claims, it is trying to defend itself against a nuclear-armed adversary bent on regime change and with which it is actually at war-the 1950-53 Korean War ended in an armistice, not a peace treaty-why should its claim to have a right to possess nuclear weapons be treated any differently from other nuclear powers?