Time‑bound enrichment caps reinforce Iran’s future nuclear options and fuel regional proliferation dynamics. A sustainable agreement requires permanent, verifiable limits aligned with NPT principles, allowing tactical flexibility on low‑level enrichment while ensuring long‑term constraints that prevent strategic ambiguity and hardliner exploitation.
According to press reports, the Trump administration and surviving elements of Iran’s government disagreed last week over whether any prohibitions on Iran’s future nuclear enrichment activities should last 20 years, as Washington wanted, or just five, as the Islamic Republic insisted.
That is the wrong way to think about the situation and the tradeoffs. It risks repeating the mistakes of President Barack Obama’s Joint Comprehensive Plan of Action with Iran, which was better than nothing, but ultimately inadequate. The biggest problem is that much of it was temporary. Limits on Iran’s future enrichment of uranium can be somewhat flexible in their specifics. But they should be permanent.
President Donald Trump appeared to reject the 20-year concept after it reached the press, but it is unclear if his administration will stick to the idea of a permanent deal. It should. Yet it can be flexible on allowing Iran limited, low-level enrichment, even in the short term. That is the better basis for a sound deal that both sides can claim as victory.
To be fair, back in Obama’s second term, Secretary of State John Kerry negotiated a deal that at least bought time. Iran was limited to about 5,000 old-fashioned centrifuges for a decade, and to a low level of uranium enrichment—far short of what is needed to make a bomb—for 15 years. Rather than pull out of the deal, as Trump did in 2018, he mighthave tried to extend those deadlines.
But the basic idea of limiting dangerous nuclear activities by a country like Iran for any limited, temporary period of time is fundamentally flawed, for three central reasons.
First, the basic international agreement about limiting the spread of the bomb, as codified in the 1968 Nuclear Non-Proliferation Treaty (NPT) to which both Iran and the United States are members, is permanent. The idea of the NPT was not to slow the spread of the bomb for a decade or two. It was to cap the number of nuclear weapons states in the world permanently—and in fact, to reduce the total number of nukes in the world (someday even aspiring to zero). That logic was airtight. And it has worked. In 1963, President John F. Kennedy thought there might be a couple of dozen countries possessing the bomb by the 1970s. Today, there are still just nine.
Second, any temporary restrictions imply that Iran might be a kinder, gentler, less extremist, and less belligerent country on some foreseeable time frame. But the Obama administration should have known better than to entertain such hopes in 2013-2015, and we should definitely know better than to believe that moderation of the Iranian regime will predictably occur on some knowable time horizon.
Third, any endorsement of temporary restrictions sends an undesirable message that Iran may someday pursue the bomb. That message may be heard by Iranian hardliners who desire such an option and interpret a finite time window as a reaffirmation of their views—as well as permission to someday pursue the nuclear weapons goal. It could also be heard by regional states like Saudi Arabia that think they, too, may need a nuclear option if Iran is retaining one.It is OK, in the pursuit of compromise, to allow Iran some (verifiable) amount of very limited nuclear enrichment—even today. That is where the Trump team can be flexible, in pursuit of a nuclear deal that would help end this war.
Of course, limited enrichment is only acceptable with the restoration of a robust monitoring and inspection system that brings all elements of Iran’s nuclear program back under International Atomic Energy Agency accountancy. A permanent agreement can only be meaningful if it provides high confidence in Iranian compliance.
But it makes no sense to set limits on Iran’s nuclear enrichment activities to a clock or a calendar, and to scale them back thereafter in the hope that the Iranian theocracy will be easier and safer to deal with in the future. That is a hope, as Colin Powell might say, not a strategy.