United States Enters a New Era of Direct Confrontation With Iran

U.S. intelligence officials assessed that reviving the deal was as unpopular among Iranian conservatives and the Islamic Revolutionary Guard Corps, which runs the military side of the nuclear program, as it was among many American critics of the arrangement. The Iranians had sought, unsuccessfully, a commitment that the United States would never again withdraw from the accord unilaterally. And they knew that once they re-entered the deal, most of the nuclear fuel Iran had amassed in response to Mr. Trump’s decision would have to be shipped out of the country.

Then came the street protests and an agreement with Russia that essentially put Iran, along with Belarus, in the position of aiding the Russian invasion.

“The regime has made a series of consequential choices that is increasingly cutting them off both from their people and from much of the international community — including European countries that had devoted the bulk of the Trump years seeking to salvage the nuclear deal,” Robert Malley, the State Department’s special envoy for the Iran negotiations, said on Tuesday.

Mr. Malley has usually been more optimistic about the chances of a diplomatic solution, but his view has clearly shifted. “Iran turned their back on a nuclear deal that was within grasp,” he said, adding that the country’s government “failed to engage” with the International Atomic Energy Agency when it demanded more visits and data to sites where nuclear material had been detected. Iran then announced plans for new nuclear production after the agency issued a resolution condemning the lack of cooperation.

The result has been “a series of vicious cycles,” Mr. Malley said. “The repression fuels more protests. The protests trigger more repression. The alliance with Russia only further isolates Iran, which prompts it to double down on this alliance for lack of any other partner.”

Of greatest concern to Israel and many in the United States was Iran’s announcement that it would begin enriching nuclear fuel to 60 percent inside Fordow, the facility it built inside a mountain, on a military base, after the repeated cyberattacks and physical assaults on the Natanz nuclear enrichment site. During the nuclear negotiations that ran from 2013 to 2015, the Obama administration tried to get the Fordow site closed. The lead negotiator, Wendy Sherman, now the deputy secretary of state, said the failure to do so was among her bigger disappointments.

Now the question is whether the more hawkish new government that Benjamin Netanyahu is trying to form in Israel will press for an attack on the facility, which would be hard to destroy except with the largest bunker-busting bombs. Both the United States and Israel have trained to conduct a strike, and Mr. Netanyahu came close to ordering one when he last served as prime minister.