A week after an explosion destroyed the power system in Iran’s Natanz nuclear enrichment facility, Iranian officials identified an Iranian suspect in an attack widely attributed to Israel. Iranian TV footage appeared to show centrifuges in operation, amid claims that “work that had been disrupted will be back on track.”
The true extent of the damage remains unclear — a midweek report by one Iranian official noted “several thousand” affected centrifuges. U.S. intelligence sources estimated repairs could take Iran nine months.
How will this attack affect Iran’s commitment and capacity to expand its nuclear program? And how will the attack influence the likelihood that the United States and Iran can reach an agreement on resuscitating the Iran deal, the Joint Comprehensive Plan of Action — or JCPOA, for short? Here’s what the research suggests.
Sabotage efforts have a short-lived effect
The history of Iran’s nuclear program suggests any impact on expansion capacity will be limited. In fact, Iran’s motive to expand its capability will probably increase — at least until the United States agrees to remove sanctions and move back toward the JCPOA.
U.S. and Israeli efforts to physically sabotage Iran’s nuclear program date back more than a decade. In 2009-2010, the Stuxnet computer worm knocked 1,000 Iranian centrifuges at Natanz out of commission. However, this represented only a fraction of Iran’s centrifuges, whose numbers quickly rebounded and continued to grow after the attack. Iran’s stockpile of enriched uranium, likewise, continued to grow. As Jon Lindsay found in a 2013 study, Stuxnet ultimately produced only a “marginal increase in friction in the Iranian program.”
In addition to conducting cyber attacks, Israel assassinated Iranian nuclear scientists, and the United States and other countries disrupted Iran’s supply chains. In a recent analysis, political scientist Richard Maher concluded that the overall impact of these activities on Iran’s nuclear program was “limited and short-lived.”
Iran’s nuclear program continued to expand until Iran and the United States, U.K., China, France, Germany and Russia — the “P5+1” — finalized the JCPOA. The 2015 deal traded sanctions relief for significant limits on Iran’s nuclear program, such as the removal of two-thirds of its centrifuges, the elimination of 98 percent of its enriched uranium, and a requirement that Iran only enrich with less efficient, first-generation centrifuges. For the first time in three decades, Iran’s nuclear capabilities were decisively and substantially rolled back.
Iran’s program remained in check until President Donald Trump’s 2018 decision to withdraw from the deal and impose harsh sanctions. Iran responded by gradually stepping back from its nonproliferation commitments and expanding its enrichment program.
This acceleration of Iran’s nuclear program seemed to prompt Israel to turn back to acts of sabotage. Last summer, an explosion — also widely attributed to Israel — seriously damaged a facility at Natanz used for assembling the advanced centrifuges Iran had been barred from using under terms of the JCPOA. The attack limited Iran’s centrifuge production in the short run, but also led to the construction of a new underground site for centrifuge assembly. Iran then moved some advanced centrifuges underground, where they are more protected from attack — and the enriched uranium stockpile continued to grow.
Iran’s initial response to this recent attack is consistent with the research noted above: Despite the damage and delay inflicted, officials in Tehran announced Iran would begin enriching uranium to 60 percent — moving closer to the 90 percent benchmark that experts generally consider weapons-grade — and would install 1,000 additional advanced centrifuges.
This response demonstrates Iran’s motivation and capability to continue to advance its nuclear program. Iran is likely to continue to expand its nuclear efforts unless and until the JCPOA is revived.
Will the attack complicate nuclear diplomacy?
The attack and Iran’s subsequent reaction could conceivably make a diplomatic solution more difficult to achieve. The attack on Natanz could empower hard-liners and reinforce the Iranian instinct to drive a hard bargain and avoid any appearance of caving in response to foreign coercion.
On the U.S. side, Iran’s enriching to 60 percent and operation of advanced centrifuges could backfire. President Biden’s administration may seek to avoid the appearance of giving in to its adversary’s pressure, both for domestic and geopolitical reasons. Or it could take a harder line in talks if it perceives Iran’s leverage has declined and the threat is less urgent as a result of the damage to its nuclear program.
In short, the attack and Iran’s response to it could make a compromise solution more difficult.
The attack puts further pressure on negotiators
But there are other reasons to believe the attack will have a limited effect — or may even facilitate the negotiations. Both Washington and Tehran may see a greater urgency to strike a deal on reviving the JCPOA, as both countries presumably have an interest in preventing further escalation in the Israeli-Iran shadow war, which has significantly increased since Iran began walking back from its JCPOA commitments.
Iran’s aggressive nuclear steps in response to the attack could also put pressure on the Biden administration to achieve a breakthrough before Iran escalates even further. Indeed, recent research by Muhammet Bas and Andrew Coe shows that nonproliferation deals are often struck in this sort of scenario — when a proliferator is relatively close to the nuclear weapons threshold, creating an urgency in the United States to solve the problem and a desire on the part of the proliferator to avoid a possible war.
Secretary of State Antony Blinken’s recent comments reflect this logic: He told the press in Brussels that Iran’s move toward 60 percent enrichment “underscores the imperative of returning to mutual compliance with the JCPOA,” even as he questioned Iran’s commitment to a diplomatic resolution.
So far, the United States and Iranian attitudes are encouraging. Iran elected not to scuttle the indirect talks ongoing in Vienna despite the attack and the two sides are apparently narrowing the gaps in their negotiating positions.
To be sure, a successful resolution is by no means guaranteed. But there is a real prospect for success — and history suggests the JCPOA has been far more effective at constraining Iran’s nuclear program than sabotage.
Nicholas Miller is an assistant professor in the Department of Government at Dartmouth College. He is the author of “Stopping the Bomb: The Sources and Effectiveness of U.S. Nonproliferation Policy” (Cornell University Press, 2018).