DUBAI — After a U.S. attack on Iran’s nuclear facilities, Iran is weighing its response — with its top diplomat saying “all options” are on the table after Washington proved “they only understand the language of threat and force.”

The United States “opted for a dangerous military operation and aggression against the people of Iran,” Iranian Foreign Minister Abbas Araghchi said Sunday, and he separately warned of “everlasting consequences.”

For Iranian officials, the choice of how to retaliate is existential. A wider war would not only risk increased violence against the Iranian state, but senior Iranian officials believe an expanded conflict could also threaten regime survival, according to analysts and officials briefed on the matter.

The Trump administration has warned Iran against retaliation. “There will be either peace or there will be tragedy for Iran, far greater than we have witnessed over the last eight days,” said President Donald Trump.

Defense Secretary Pete Hegseth said at a Pentagon news conference Sunday that “this mission was not and has not been about regime change.” He said messages have been delivered to Iranian officials that “now is the time to come forward for peace.”

But after more than a week of war, it’s unclear how easily Iranian officials are able to communicate and plan. One European official briefed on the matter said calls scheduled between senior Iranian officials and their foreign counterparts have dropped or had to be repeatedly rescheduled in recent days because of connectivity issues.

Those kinds of communications disruptions could have an impact on decision-making in the moment, but Iran anticipated possible U.S. strikes for days, said Vali Nasr, a professor of Middle East and international studies at the Johns Hopkins School of Advanced International Studies. “This is not a sudden decision for them. I think they’ve had a week, and perhaps even before the war started they had time to think about what their options are.”

Nasr said Iran could try to mitigate the fallout from a strike on U.S. interests by providing advance warning. Or, he said, Iran may intensify strikes against Israel, a move that would save face but might not invite further escalation from the United States.

“It is not retaliation out of revenge; it is retaliation to try to create deterrence,” he said. “The response has to have a purpose, in the sense of managing the next stage.”

Because of their proximity, U.S. bases in the region are particularly exposed. Iranian officials have previously warned that U.S. bases would be considered “legitimate targets” in the event of U.S. intervention, and Iran’s powerful Islamic Revolutionary Guard Corps described them Sunday as a “vulnerability.”

“The number, dispersion and size of U.S. military bases in the region have not been a strength, but have doubled their vulnerability,” the IRGC said. “Washington effectively placed itself on the front lines of aggression.”

In the hours after the U.S. strikes, Iran shot back at Israel, firing two volleys of over 20 ballistic missiles. The attacks penetrated Israel’s sophisticated air defenses, hit residential buildings and wounded 86 people, according to Israel’s Health Ministry.

Support is also building in Iran for a withdrawal from the nuclear Non-Proliferation Treaty, a move that would make it more difficult to monitor and verify the country’s nuclear program. “With the U.S. attack on nuclear facilities, there is no longer any reason to continue cooperation in the form of safeguards,” Mohammad Saleh Jokar, the head of the Iranian parliament’s Commission for the Country’s Internal Affairs, told state-run media.

Such a move could “set nonproliferation efforts in Iran back for decades,” said Sina Azodi, an expert on Iran and a lecturer at George Washington University. “This would mean that Iran goes nuclear, but then there is absolutely no monitoring of the Iranian nuclear program,” he said. “I can’t emphasize how dangerous this can be.”

But a senior Israeli official, speaking on the condition of anonymity to discuss internal deliberations, said: “If the Iranian regime decides to go on without any agreement and to try to rebuild again, they should understand that it won’t be a huge challenge for us to get there again and destroy it again. So, I think this regime will think now 100 times before doing anything.”

The International Atomic Energy Agency chief, Rafael Mariano Grossi, said in an X post that he is convening an emergency meeting Monday “in light of the urgent situation in Iran.” No increased levels of radiation were detected at the sites that were struck, according to the U.N. nuclear watchdog’s statement.

It’s unclear how much damage was done to the Iranian nuclear sites. Trump said three nuclear facilities — including the heavily fortified Fordow; the main uranium enrichment site, Natanz; and the Isfahan facility — were “obliterated.” The senior Israeli official said that Isfahan was “annihilated” and that Fordow and Natanz were “severely damaged.”

Iranian officials downplayed the impact, saying that the facilities that were struck had been evacuated and that nuclear material was moved elsewhere.

Gen. Dan Caine, chairman of the Joint Chiefs of Staff, said at a briefing Sunday that the facilities “sustained extremely severe damage” but that it was too early to determine the scale of destruction.

Araghchi said at a news conference Sunday that he did not have “exact information about the level of damages.” In the lead-up to the U.S. attacks, Arab officials in the region were engaged in high-level diplomacy to prevent further escalation, encouraging Iran and the U.S. to return to the negotiating table. Iranian officials have previously said they are prepared to talk with the U.S. but insisted that Israeli strikes cease before formal negotiations could begin.

Araghchi accused Washington and Israel of scuttling diplomatic efforts, after Friday’s talks with European foreign ministers in Geneva ended without a breakthrough.

Inside Iran, people reached by The Washington Post said they are bracing for a more prolonged conflict. “The fact that America has entered this war is really a shock for all of us,” said a woman who fled her home in Tehran for Iran’s central Isfahan province. Like others, she spoke on the condition of anonymity for fear of government reprisal.

“If, in the first days of the war, people thought that there would be some limits, that they’ll return again to negotiations, right now, the main dread is that this war will stretch on,” she said.

A businessman in Tehran said Iranians are bracing for more economic repercussions if the conflict stretches on. Already in the past week, Iranian businesses were seeing sharply reduced revenue and beginning talk of layoffs, he said. “It’s a mix of despair and fear right now,” he said.

People who fled Tehran are also wondering when they can return to their homes, and worry that water and electricity might get cut off as part of prolonged fighting, said the Iranian woman. “These have become much more serious concerns,” she said, adding that she and her family are so afraid that gasoline supplies will be affected that they don’t dare to drive anywhere, choosing to walk instead.

The businessman in Tehran said Iranians had for years imagined the possibility of an American attack and saw it as a sort of “final stage,” indicating an imminent, more dangerous phase of conflict. “From a mental perspective, people feel that they’ve entered the final stage that they always feared,” he said

Torbati reported from Portugal. Souad Mekhennet in Washington, Abbie Cheeseman in Beirut and Leo Sands in London contributed to this report.

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