Commentary Magazine


A Little Perspective on Stuxnet

Mahmoud Ahmadinejad has finally acknowledged that Iran’s been having centrifuge problems induced by an IT attack, as Alana Goodman noted. The apparent culprit, the Stuxnet worm, is undoubtedly elegant: brilliantly conceived and executed with patience and subtlety. But for all its deserved notoriety as an IT phenomenon, excitement over Stuxnet is distracting us from the fact that its effects have not changed the cost-benefit calculus of interdicting Iran’s nuclear-weapons program. We’re missing the big picture here.

The attempted assassination of two Iranian scientists this week highlights that reality in jarring fashion. If these attempts — much like another one in January — were mounted by a foreign government, the purpose was to eliminate two of the scientists most prominent in the weaponization effort. Of the three elements of a nuclear-weapons program — weaponizing a warhead, enriching uranium, and acquiring delivery platforms (e.g., missiles) — it is weaponization that has become, in Iran’s case, the crucial bottleneck on which to focus efforts at sabotage. Weaponization is the program element Iran hasn’t mastered yet. The payoff from targeting weaponization is that we might still avert the development of an operational bomb.

Stuxnet, apparently targeted at the industrial uranium-enrichment process, didn’t offer that payoff. Iran already has enough low-enriched uranium (LEU) for three to four warheads, with over 3,100 kg stockpiled as of October 2010. Some portion of that LEU was produced, in fact, during the period of vulnerability to Stuxnet. As long as the worm went undetected, it could interfere with rote uranium-enrichment operations. But its achievements must be viewed in context: the International Atomic Energy Agency’s data indicate that the rate of LEU production at Natanz showed an increasing overall trend during the period when Stuxnet could have been in operation (scroll down at the last link above to see the graphs). In the same period, the Iranians also inaugurated — and enjoy continued success with — their higher-purity enrichment process.

If the rate and efficiency of uranium enrichment didn’t increase as rapidly as they would have without sabotage from Stuxnet, that’s a good thing. But it remains to be seen if Iran’s rate of uranium enrichment can be held back now that the worm is a known quantity. Slowing the stockpiling rate is, moreover, a secondary objective. As North Korea has demonstrated, the political impact of obtaining nuclear weapons occurs at the threshold, with the first detonation. Warhead weaponization is what needs to be prevented — and Stuxnet’s characteristics are irrelevant to that leg of the effort.

Sanctions may impose some additional delays on Iranian progress. But the longer we wait, the higher will be the price of interdicting any particular aspect of the Iranian nuclear-weapons program. Iran has enough LEU for three to four bombs, it is already enriching uranium to higher purity, and it has already tested missiles that can carry a usable nuclear warhead to Israel and other parts of the Middle East. Stuxnet hasn’t changed any of that.