As America assumes the rotating presidency of the United Nations Security Council for the month of August, President Biden faces a dilemma in two months: keeping his promise to revive the 2015 Iran nuclear deal could put America in violation of a UN resolution. 

Lacking a Senate majority to ratify the nuclear deal America cut in 2015 with five world powers and Iran, President Obama asked the Security Council to endorse the pact, known as the Joint Comprehensive Plan of Action. The UN’s top body dutifully passed resolution 2231, which obligated all members of the UN to abide by the nuclear deal’s provisions. 

As agreed to by the writers of the JCPOA, the council resolution included several sunset clauses gradually rescinding sanctions that had previously been imposed on Iran. In return, the Islamic Republic was to take steps to end its nuclear arms pursuit. One of these sunsets is due in October. 

According to the resolution, eight years after its enactment the council must lift restrictions related to Iran’s import and export of ballistic missiles and unmanned aerial vehicles. Yet, until that date arrives, in October, sanctions remain.

Therefore, Russia’s “use of Iranian UAVs is a violation of UN Resolution 2231,” the American ambassador at the UN, Linda Thomas-Greenfield, told reporters on Tuesday, as she assumed the council’s presidency. “We have asked the UN for an investigation, particularly as it relates to the use of these UAVs in Ukraine by Russia.” She added that the use of Iranian drones anywhere else “should be condemned and part of an investigation, because it does violate 2231.”

While Ms. Thomas-Greenfield sticks to the language of resolution 2231, American and European diplomats say they plan to maintain some sanctions related to Iran’s missile and drone exports even after October, when according to the resolution they must lift them. That could leave the Western council members open to allegations that they, rather than Russia or Iran, are violating the security council resolution.    

For months Russian diplomats have pushed back against Western allegations that Moscow’s purchase of drones from Iran violates resolution 2231. Yet, after the council missile ban sunsets in October, Russia, Communist China, and Iran “will seek to flip the script,” a former White House official under President Trump who dealt with Iranian sanctions, Richard Goldberg, tells the Sun.

America and the three European powers that negotiated the JCPOA — Britain, France, and Germany — “have hooked their entire narrative to the council resolution,” Mr. Goldberg, who serves as a senior adviser at the Foundation for Defense of Democracies, says. “Now they don’t have anything to hang their hats on. Russia will say ‘you are violating international law and standards.’ This is a huge propaganda victory for the other side.”

America or its European partners could nevertheless prevent the fiasco by triggering the snapback mechanism that was built into the council resolution. That clause allows any of the five council permanent members, as well as Germany and Iran, to unilaterally annul the entire resolution.  

In selling the JCPOA to Americans back in 2015, Secretary Kerry told the Council on Foreign Relations that “one country alone, the United States,” can invoke the snapback, and “we don’t continue the lifting [of previous sanctions], and they all snap back.” 

Yet, in 2020, when President Trump invoked the snapback clause at the UN, the rest of the countries on the 15-member council argued that America had no leg to stand on, as it had left the JCPOA two years earlier. 

Britain, France, and Germany, known as the E-3, agree with Ms. Thomas-Greenfield that Iran is violating resolution 2231 by exporting drones to Russia. On July 20 the European  Union imposed new sanctions on Iran for its “military support of Russia’s war of aggression against Ukraine.”

One of the E-3 or all of them must soon invoke the snapback option, which takes effect 30 days following such invocation. Otherwise they would be in violation of the sunset clause, which demands all EU sanctions be lifted by October. 

As of yet, none of the E-3 is contemplating such a move, three UN-based diplomats told the Sun. Nor is America urging them to do so — or to renew Mr. Trump’s 2020 snapback. That is because even without its Iran pointman, Rob Malley, Washington seems eager to reach a diplomatic understanding with the mullahs. 

The EU and America are in an awkward position. To maintain their opposition to Iran’s aid to Russia’s Ukraine war — not to mention mass proliferation of Iranian drones to Latin America, Asia, and Africa — their best option is to give up the dream of renewing the JCPOA.

They can do so by ending the UN resolution that endorsed it. If they don’t, and if they maintain sanctions past their expiration date, Western powers risk violating that resolution. That would be an uncomfortable position for advocates of a strong UN and a rules-based world order.