Europe Started Snapback. The U.S. Must See It Through.

Our European allies just took the first big step to “snap back” tough UN sanctions on Iran. Their ultimate success can help stabilize the Middle East, impede Russia-Iran security ties, and build bargaining power for Ukraine talks. American leadership now becomes crucial as Moscow and Tehran try to prevent snapback’s completion and undermine its effectiveness.

The sanctions in question are six UN Security Council resolutions enacted in 2006-10 in response to Tehran’s nuclear safeguards violations. These measures prohibit Iran’s uranium enrichment, impose two-way arms embargos on its nuclear, ballistic missile, and conventional weapons arsenals, and sanction key officials directing these efforts. All UN member states are bound to enforce these bans within their own territories, and they also provide the legal basis for U.S. and European secondary sanctions targeting the Iranian regime’s most dangerous activities.

For all these reasons, senior Iranian officials worry their country “does not have the financial or military capacity to endure” the return of UN sanctions—“they are more damaging than war.” Russia would also feel the pain, since Iran’s military assistance reinforces Putin’s unyielding ceasefire demands at Ukrainian, U.S., and European expense.

Iran’s JCPOA violations made snapback possible, but this option is only valid until October 18. The actual process takes at least a month, meaning the JCPOA’s “E3” parties (Britain, France, Germany) waited until the eleventh hour to invoke it. Though they cannot veto this procedure, Russia and China can use their Security Council positions to drag it out and try to kill the clock. This becomes particularly troublesome once Moscow assumes the council’s rotating presidency in October.

Iran and Russia are already working to delay and delegitimize snapback by throwing out red herrings. They highlight Iran’s ability under the JCPOA to expand enrichment after President Trump left the agreement in 2018, while falsely accusing the E3 of violating the agreement. But they omit Iran’s failure to divulge its covert weaponization work when implementing the deal.

Moscow also encourages Tehran to play for time. The E3 avoided fulfilling previous pledges to trigger snapback, so Iran might exploit this situation by offering yet further discussions about resuming nuclear negotiations. Following talks with the E3 in July and August, it is easy to imagine Tehran pledging to reach an understanding at a third meeting in late September—but only after snapback is axed.

This is where more U.S. concerted involvement will be critical. The Trump administration has supported snapback from the sidelines, but the best way to ensure success is by encouraging the E3 to completely reset its Iran outreach. Citing the regime’s willful failures, for years, to address the world’s rising concerns about its nuclear program, America and Europe should close ranks to declare that snapback shuts tight the current window for diplomacy.

At the same time, they should offer to re-lift these embargoes in a future deal if Iran finally gets serious about ending its nuclear weapons program verifiably and permanently. Tehran’s long track record of bad-faith diplomacy should also be used to counter Iranian and Russian disinformation aimed at undercutting snapback compliance. But more concrete action is needed, too.

Like it did last year on North Korea, Moscow will veto any UN Panel of Experts to enforce renewed sanctions. Coordinating with Europe and others, the United States can work through less formal institutions like the Proliferation Security Initiative to maximize global adherence. Iran and Russia might well flout international law, but other countries will be reticent to join in if a broad U.S.-led coalition conducts effective oversight and discourages flagrant UN violations. A more unified front here also minimizes the transatlantic daylight that Putin exploits for his own ends in Ukraine.

Snapback has been a long time coming, but it has only started. American diplomacy must push it over the finish line to gain valuable leverage against two of our biggest adversaries.