The Red-Zone Theory of the Iran Nuclear Deal

It's fortuitous that a nuclear agreement with Iran was announced just days before Thanksgiving, a time when football crowds out foreign policy. Summarized in a single, simple bottom line, the interim deal announced on Sunday will roll back Iran’s nuclear drive from our red zone to the 30-yard line. As Chart 1 illustrates, over the past four years, without any constraints on its nuclear program, Iran has marched relentlessly toward our goal line.

As Chart 2 shows, the agreement, if implemented, will push Iran back from our 10-yard line, out of our red zone, to the 30-yard line. Having an opponent 30 yards away from one’s goal line is not comfortable, but it is nonetheless a lot better than having that opponent be just several yards shy of the end zone.

The terms of the interim deal call for Iran to stop all enrichment of uranium to the 20-percent level. Moreover, they require Iran to eliminate its stockpile of almost a bomb’s worth of 20 percent-enriched material accumulated since 2010. For many observers, this may seem like a technical distinction without a difference, since Iran will continue operating centrifuges that produce 3.5 percent-enriched uranium, adding to a stockpile that is already sufficient, after further enrichment, for nearly seven bombs.

But the difference really matters. When a state has enriched uranium to 3.5 percent (the level used to fuel a civilian nuclear power plant), it has done seven-tenths of the work to produce bomb-usable material (which is 90-percent enriched). When that material is enriched further to 20 percent, nine-tenths of the work required to make bomb-usable material has been completed.

It is instructive to recall that when Israeli Prime Minister Benjamin Netanyahu attempted to sound the alarm about the Iranian nuclear program in his speech at the United Nations last year, he focused on this same yardstick in his oft-cited graphic illustrating Iran’s progress toward a bomb. He drew a new red line onto his cartoon diagram: one bomb’s worth of 20 percent-enriched uranium. (Israeli officials later clarified that this was equivalent to 250 kilograms of 20 percent-enriched uranium in hexafluoride form.)

As Chart 4 shows, by the prime minister’s metric, the interim agreement not only requires Iran to respect Bibi’s red line. It goes beyond what he demanded, forcing Iran to eliminate the nearly one bomb’s worth of 20 percent-enriched material by diluting or converting it to oxide to fuel the country's research reactor.

Of course, a challenge as complex as Iran’s nuclear ambitions cannot be captured by any single measure. Other key metrics include the number and production rate of centrifuges installed and operating, which the agreement freezes; the frequency of international inspections of ongoing enrichment activity, which the agreement advances from once a week to daily; and the speed at which construction of a further plutonium-producing reactor at Arak progresses, which the agreement slows, stopping all critical advances for six months.

In sum, the interim agreement to push Iran back 20 yards on its fastest path to a bomb, stop its advance on other fronts, and expand international inspections of ongoing activities is a modest but significant first step. Moving beyond this deal to a comprehensive agreement that pushes Iran further away from an exercisable nuclear weapons option will prove much more important—and much more difficult. But if we compare where Iran is today with where it will be over the next six months under the agreement, we are clearly better off. And if we compare where Iran’s nuclear program will be over the next six months with where it would have advanced in the absence of an agreement, we are even better off.