The Key to a Nuclear Agreement with Iran? The Window of Vulnerability


For the past year, the debate on Iran’s nuclear program has focused far too much on the various technical components without examining the sum of its parts. The objective for the United States in the negotiations should not be focused on any one component (e.g. centrifuge numbers), but instead on obtaining an agreement that creates the conditions that will deter Iran from ever trying an overt or covert breakout to a nuclear weapon.

To construct such an agreement, it is important to first understand Iran’s nuclear strategy. Since the start of the Obama administration, Iran has been within a year’s time of obtaining enough nuclear material for a bomb. However, in all of this time, Iran has not actually gone for a bomb. That is because the final steps necessary to reach over 90% highly enriched uranium are quite conspicuous and cannot be explained away as dual use activities meant for Iran’s civilian nuclear energy program. Any attempt to pursue this course of action would be quickly noticed, creating a window of vulnerability during which Israel, the United States, or some international coalition could strike the program and set it back. Iran has slowly sought to shrink this window of vulnerability so that should it ever decide to break out, it would be able to do so with less risk. This strategy has entailed bringing on more centrifuges, improving their efficiency, increasing stockpiles of low enriched uranium, and building facilities that are more difficult to attack. The real measure of whether any final deal can be effective is whether an agreement can reverse this trend and put the Iranians far enough away from a nuclear weapon that they will never dare take the risk of pursuing a breakout. In other words, a deal has to keep that window of vulnerability large enough.

To do so, any agreement will have to address the two most likely ways for Iran to break out to a nuclear weapon. The first is an overt “dash” where Iran would use all of its existing nuclear facilities, which are closely monitored by the International Atomic Energy Agency (IAEA), to produce the 90% highly enriched uranium necessary for a bomb as quickly as possible. In this scenario, the Iranians would do all they could to obfuscate early on in the dash and create confusion about precisely what was occurring at their facilities. But they would have to take steps such as reconfiguring centrifuges to enrich uranium that would very quickly give away their intentions.

Most nuclear experts estimate that if Iran were to decide to pursue an overt dash today, it could produce enough highly enriched uranium for one bomb in roughly two to three months. The Obama administration’s objective during the negotiations has been to get an agreement on technical arrangements that would raise this dash time to one year. These time estimates assume a best-case scenario for the Iranians where everything goes right the first time they try it. In reality, there would likely be unexpected delays and challenges that would lengthen the process if Iran sought to build a bomb. These estimates also assume that Iran would dash to only one bomb, which is something no nuclear state has ever done. Instead, Iran would likely need to dash to a small arsenal of perhaps six to eight weapons in order to have a credible arsenal.

The type of agreement that is currently being contemplated would likely put the Iranians a couple of years away from a small arsenal. This creates a significant zone of vulnerability for them if they were ever to choose to dash. It is more than enough time for the United States to catch the Iranians cheating, build the political consensus for action at home, and cobble together an international coalition that could take military action. The very fact that the United States would have time to mount a response would very likely deter the Iranians from ever trying to dash in the first place.

The second option for a breakout would be a covert “sneak out,” in which the Iranians would try to use an entirely new set of facilities that has not been detected by the IAEA. The good news is that such an approach is very difficult to carry out and would take a few years. Iran has twice tried to build covert nuclear enrichment facilities, first at Natanz and then at Fordow. Both times these facilities were detected and outed to the world long before they ever came on line.

The sneak out scenario can be addressed by creating monitoring and verification mechanisms that will make it exceedingly difficult for Iran to secretly develop covert facilities. This should involve cradle to grave monitoring that starts with Iran’s uranium ore mining facilities and goes through the final steps of enrichment. It need not involve carte blanche access to every facility at every moment, but sufficient access is necessary to ensure that there is no credible way for the Iranians to cheat without taking significant risks.

In addition to the official agreement, the United States could stress to Iran the costs of violating an agreement, further deterring the Iranians from pursuing a breakout. Here, Congress can play a valuable role by passing legislation that would clearly outline severe consequences to Iran for failing to follow through on the nuclear agreement. Such action would be much more constructive than pushing for sanctions now that are more likely than not to undermine the ongoing negotiations.

In the end, the purpose of a nuclear agreement is not to create a one hundred percent foolproof way to stop Iran from pursuing a bomb. Even an agreement that did not allow for any enrichment would not do that because the Iranians would retain the know-how to restart the program at any time. And that deal is unattainable anyway since the Iranians would never agree to it. Instead, the purpose of a good deal is to create a situation where the risk of pursuing a nuclear weapon is so high and the window of vulnerability is so long, the Iranians would never dare try it.


Ilan Goldenberg is the Director of the Middle East Program at the Center for a New American Security. He previously served as the Iran Team Chief in the Office of the Secretary of Defense.


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