Obama, the Sinking of the Cheonan, and the Failure of Nuclear Deterrence

States like Kim’s Korea, however, may look at Washington’s so-far inadequate response to the Cheonan incident and believe that a future act of nuclear terrorism just might go unpunished. If so, deterrence could fail.

How could that happen? It would take weeks — and perhaps months — to conclusively determine the source of fissile material used by nuclear terrorists. The International Atomic Energy Agency, the home of “cutting-edge forensics,” can find a particle that is out of place and measure things that weigh no more than a femtogram, 0.000000000000001 of a gram. Its technicians can look at the smallest speck of uranium and find out how it was formed.

But the IAEA’s near-magical work takes time, just as it took time to establish responsibility for the Cheonan’s sinking. Intelligence analysts knew within hours that the North Koreans used a torpedo to sink the vessel, but detective works requires patience — in this case, more than seven weeks — to find, analyze, and present evidence.

As hours turn into days, days into weeks, and weeks into months, the certainty of a retaliatory response decreases. In our complex world, there is always a reason not to act, and those reasons grow stronger over time. In the Cheonan case, we are already hearing the calls for South Korea to move on and consider “the broader issues.”

Secretary of State Clinton, when she was in Tokyo on Friday, ruled out a purely regional reaction to the Cheonan’s sinking and signaled that China, Pyongyang’s best friend, would have to be part of the world’s response. Yet six decades of history show that China will not permit the international community to punish the North in any serious fashion. In short, the Obama administration looks like it will, once again, let Kim Jong Il off lightly.

“Deterrence requires a combination of power, the will to use it, and the assessment of these by the potential aggressor,” noted Henry Kissinger. “Moreover, deterrence is the product of those factors and not the sum. If any of them is zero, deterrence fails.”

Deterrence looks like it might fail soon. The Cheonan incident could convince Chairman Kim and other potential aggressors that they will pay no price for committing horrible acts. Even in such a clear-cut circumstance as the sinking of the South Korean frigate, the international community is having trouble imposing punishments on the aggressor.

When responsibility is murkier, the urge to retaliate will be even more muted. And that can give ideas to terrorism-sponsoring states. Take Iran, for instance. As the Islamic Republic builds its links with al-Qaeda and accelerates the enrichment of uranium, we have to wonder whether the mullahs think the slow — and uncertain — response to the sinking of the Cheonan will make nuclear terrorism a possible option for them.

So there is a lot riding on Washington’s response to the sinking of the Cheonan. This is not just about South Korea.