Carlos Barria / Reuters

President Donald Trump decried Tuesday what he called Iran’s “brutal” regime and said the multilateral nuclear agreement with the Islamic Republic provided its leaders with a “windfall” they’re using to “sow chaos, death, and disruption.”

“We cannot allow the world’s leading sponsor of terrorism to possess the planet’s most dangerous weapons,” Trump told the United Nations General Assembly. “We cannot allow a regime that chants ‘Death to America’ and threatens Israel with annihilation; they cannot possess the means to deliver a nuclear warhead to any city on Earth. We just cannot do it. We ask all nations to isolate Iran’s regime as long as its aggression continues, and we ask all nations to support Iran’s people as they struggle to reclaim their religious and righteous destiny.”

The U.S. might have to wait. Trump’s remarks came a day after the European Union and other signatories to the nuclear agreement announced a new mechanism to effectively bypass U.S. sanctions. The announcement, which at the moment is mostly symbolic, represents the chipping away at the U.S. sanctions regime by arguably its most important ally. It also represents a temporary political victory for Hassan Rouhani, the Iranian president, who has been vilified at home for, in the view of his political rivals, giving away the country’s nuclear program with nothing to show for it. Perhaps most significantly, it represents another rupture in U.S.-EU relations that have already been hurt by the U.S. withdrawal from the Paris climate accord, Trump’s questioning of the U.S. commitment to NATO, and his imposition of steel and aluminum tariffs on the bloc. Trump’s remarks on Iran merely highlighted the growing divisions in the transatlantic alliance.

“Iran’s neighbors have paid a heavy toll for the agenda of aggression and expansion,” Trump said at the UN. “That is why so many countries in the Middle East strongly supported my decision to withdraw the United States from the horrible 2015 Iran nuclear deal and reimpose nuclear sanctions.”

The president’s remarks represent an intensifying of the U.S. pressure on Iran that began with the Trump administration’s withdrawal in May from the Joint Comprehensive Plan of Action (JCPOA), as the nuclear accord that was signed in 2015 is officially known. That decision, which came despite U.S. acknowledgement that Iran was abiding by the agreement, deepened a divide with U.S. partners in Europe that were also signatories to the deal. In the months since then, the U.S. has snapped back some sanctions on Iran and worked to ensure global compliance as it prepares to reimpose the most punitive measures that target the Islamic Republic’s oil exports and payments from its central bank. Its stated goal is to persuade buyers of Iranian oil to reduce their imports to zero. This would devastate Iran’s already vulnerable economy.

“In practical terms, this will mean that EU member states will set up a legal entity to facilitate legitimate financial transactions with Iran, and this will allow European companies to continue to trade with Iran in accordance with European Union law and could be open to other partners in the world,” Federica Mogherini, the EU’s foreign-policy chief, said after she met with foreign ministers from China, France, Iran, Germany, Russia, and the U.K. at the UN, where world leaders are gathering for the annual General Assembly. She added that technical experts from the remaining states will now meet to make the “special-purpose vehicle” a reality. Any such mechanism will likely be ready before November 4, when the oil-related U.S. sanctions on Iran go into effect. But the move will be unable to prevent the U.S. Treasury Department from sanctioning the acquisition of Iranian oil, an act that itself violates U.S. law.   

Richard Nephew, the former deputy coordinator for sanctions policy at the U.S. State Department who was on the U.S. team that negotiated the nuclear deal, said on Twitter that the EU announcement was unlikely to prevent the sanctioning of firms that trade with Iran. “And its [sic] why payment systems aren’t enough,” he wrote. “If the EU and others are to succeed, they need companies prepared to be sanctioned. Most majors won’t be. I believe that … [small and medium enterprises] might, if properly incentivized. That’s what this effort—among others—is intended to do.”

Robert Malley, who was the lead White House negotiator of the Iran nuclear agreement, said Monday on a conference call with reporters that the U.S. and Europe clearly disagree on this issue, and it will be up to the U.S. to determine “if they really want to punish the Europeans after they devise the mechanism that in theory would be immune from U.S. sanctions.” He said the U.S. determination will be made “based on the totality of the relationship with Europe.”

U.S. participation in the JCPOA, which was negotiated by the Obama administration, was on deathwatch the moment Trump won the 2016 election. Trump had railed against the accord, calling it the “worst deal in history.” Critics of the agreement said it gave Iran too many incentives while merely freezing but not eliminating its nuclear program. Supporters of the JCPOA reject this claim. Moreover, the critics of the deal say, it did nothing to address Iran’s problematic policies in the Middle East, its threats to Israel, and its ballistic-missile programs. The accord’s supporters said the JCPOA was intended solely to eliminate the threat posed by Iran’s nuclear program, and that those other issues, while significant, could be dealt with in the future.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.