That said, it’s true that for some purposes it makes sense to focus on breakout time in the narrow, conventional sense—the time it takes to produce just the uranium for a nuclear weapon, not the weapon itself. In the event that Iran sought to build a nuclear weapon, the United States and Israel have said they would use military force to stop it. And that mission would presumably be most feasible when the material for a weapon was still being produced at known enrichment facilities. So in terms of military tactics, breakout time in the strict sense—the time that is currently estimated as about two months—does matter.
On the other hand, once you start thinking about military tactics, questions arise as to whether there’s much practical difference between a two-month breakout capacity and the American goal of a six-to-12-month breakout capacity. Contingency plans for bombing have no doubt already been drawn up, so, as a strictly military matter, the highest-priority strikes could be initiated within weeks if not days of discovering that Iran was pursuing a nuclear weapon.
Of course, the United States might precede a military strike by trying to amass international support. But there would be virtually no hope of giving these strikes the sanction of international law through U.N. Security Council authorization, because that would require the approval of both Russia and China. If breakout was proceeding, and the only way to disrupt it was to act within weeks, the United States and Israel would act within weeks—illegally, maybe, but decisively. So extending the breakout time from two months to six months wouldn’t have a very clear impact on Iran’s ability to violate the terms of a deal with impunity—and therefore would have little impact on Iran’s incentive to comply with the deal.
One thing that would impact both Iran’s incentives and the American capacity to impede its nuclear breakout is not reaching any deal at all. The above scenario—bombing Iran within weeks of breakout—assumes that U.S. officials would know when breakout had commenced. Right now they have high confidence of detecting breakout because of the monitoring and inspection procedures that were implemented under the November interim deal—and that would be expanded as part of a final deal.
But if there is no deal, and hence no prospect of further sanctions relief, Iran could be expected to return to the weaker monitoring regime that preceded the interim deal or to abandon that regime entirely. Then there might be no way of knowing if or when breakout had started. And, over time, as the Iranian nuclear program evolved in darkness, there would be less and less certainty about the best way to disrupt a dash for the bomb in the event that such a dash became apparent.
In short, a breakout capacity of any duration—two months, six months, whatever—has a very different meaning under circumstances of transparency than under less transparent circumstances. Becoming so focused on incremental differences in breakout capacity as to lose sight of this fact is not in America’s interests.
There’s a second, and related, reason that preoccupation with breakout capacity is misguided. The U.S. intelligence community assesses that, if Iran did decide to pursue a nuclear weapon, it probably wouldn’t do so by using its existing, closely monitored nuclear infrastructure. Rather, Iran would develop secret enrichment facilities and indeed an entire secret weapons manufacturing infrastructure.
This “sneakout” scenario further underscores the value of reaching a deal with Iran. A final deal is widely expected to include Iran’s acceptance of the “additional protocol” to the Nuclear Non-Proliferation Treaty. That would not only expand the list of “declared” facilities subject to inspection, but would also give international inspectors the right to inspect undeclared facilities that aroused suspicion. This intrusive monitoring would make covert breakout more likely to be detected—and thus less likely to happen in the first place.
As the U.S. intelligence community has consistently noted since 2007, Iran has the scientific, technical, and industrial capacity to eventually produce nuclear weapons if it chooses to do so. Though repeated bombing could disrupt a weapons program, there is no way to reliably stop it short of a ground invasion and long-term occupation.
So the most realistic goal in Vienna isn’t to make breakout impossible, but to make it a difficult and unattractive option for Iran. Once you see that as the goal, you realize that the gains in transparency from any likely deal—extremely close monitoring of declared facilities and the power to inspect undeclared facilities—should be at the forefront of American thinking about this problem. It would be a mistake to sacrifice such transparency in a failed attempt to reduce Iran’s breakout capacity by some arbitrary increment that is actually less valuable than many in Washington think it is.
A common refrain among U.S. and Israeli officials has been that a bad deal is worse than no deal. Well, yes; since one common definition of a bad deal is a deal that’s worse than no deal, that aphorism is hard to argue with. But the question being begged here is: Which deals would truly be worse than no deal?
The key to answering this question intelligently is twofold: realize that the practical differences among the various deals being seriously discussed in Vienna have been exaggerated by misunderstanding the meaning and implications of “breakout capacity”; and realize that the contrast between the virtues of any of these deals and the perils posed by reaching no deal at all is much starker than is generally appreciated.
Once you see this, you see that there’s little chance of American negotiators signing on to a truly bad deal. The more likely danger is that they’ll turn down a deal that’s much better than no deal.
This article was published in collaboration with the American Foreign Policy Project.