WASHINGTON — President Donald Trump on Sunday called into question the future of Iran’s ruling theocracy after a surprise attack on three of the country’s nuclear sites, seemingly contradicting his administration’s earlier calls to resume negotiations and avoid an escalation in fighting.

“It’s not politically correct to use the term, ‘Regime Change,’ but if the current Iranian Regime is unable to MAKE IRAN GREAT AGAIN, why wouldn’t there be a Regime change???” Trump posted on social media. “MIGA!!!”

The posting on Truth Social marked something of a reversal from Defense Secretary Pete Hegseth’s Sunday morning news conference that detailed the aerial bombing.

“This mission was not and has not been about regime change,” Hegseth said.

What the administration has made clear is that it wants Iran to stop any development of nuclear weapons, with Secretary of State Marco Rubio warning on Fox News’ “Sunday Morning Futures” that any retaliation against the U.S. or a rush toward building a nuclear weapon would “put the regime at risk.”

But beyond that, the world is awash in uncertainty at a fragile moment that could decide whether parts of the world tip into war or find a way to salvage a relative peace. Trump’s warning to Iran’s leadership comes as the U.S. has demanded that Iran not respond to the bombardment of the heart of a nuclear program that it spent decades developing.

The Trump administration has made a series of intimidating statements even as it has simultaneously called to restart negotiations, making it hard to get a complete read on whether the president is simply taunting an adversary or using inflammatory words that could further widen the war between Israel and Iran that began earlier this month.

Up until the president’s post on Sunday afternoon, the coordinated messaging by Trump’s vice president, Pentagon chief, top military adviser and secretary of state suggested a confidence that any fallout would be manageable and that Iran’s lack of military capabilities would ultimately force it back to the bargaining table.

Hegseth had said America “does not seek war” with Iran, while Vice President JD Vance said the strikes have given Tehran the possibility of returning to negotiate with Washington.

But the unfolding situation is not entirely under Washington’s control, as Tehran has a series of levers to respond to the aerial bombings that could intensify the conflict in the Middle East with possible global repercussions. Iran can block oil being shipped through the Strait of Hormuz, attack U.S. bases in the region, engage in cyberattacks or double down on a nuclear program that might seem like more of a necessity after the U.S. strike.

All of that raises the question of whether the strikes will open up a far more brutal phase of fighting or revive negotiations out of an abundance of caution. Inside the U.S., the attack quickly spilled over into domestic politics with Trump choosing to spend part of his Sunday going after his critics in Congress.

Trump, who had addressed the nation from the White House on Saturday night, returned to social media Sunday to lambaste Rep. Thomas Massie, R-Ky., who had objected to the president taking military action without specific congressional approval.

“We had a spectacular military success yesterday, taking the ‘bomb’ right out of their hands (and they would use it if they could!)” Trump said as part of the post on Truth Social.

At their joint Pentagon briefing, Hegseth and Air Force Gen. Dan Caine, chairman of the Joint Chiefs of Staff, said that “Operation Midnight Hammer” involved decoys and deception, and met with no Iranian resistance.

Caine indicated that the goal of the operation — destroying nuclear sites in Fordo, Natanz and Isfahan — had been achieved.

“Final battle damage will take some time, but initial battle damage assessments indicate that all three sites sustained extremely severe damage and destruction,” Caine said.

Vance said in a television interview that while he would not discuss “sensitive intelligence about what we’ve seen on the ground,” he felt “very confident that we’ve substantially delayed their development of a nuclear weapon.”

Pressed further, he told NBC’s “Meet the Press” that “I think that we have really pushed their program back by a very long time. I think that it’s going to be many, many years before the Iranians are able to develop a nuclear weapon.”

The vice president said the U.S. had “negotiated aggressively” with Iran to try to find a peaceful settlement and that Trump made his decision after assessing the Iranians were not acting “in good faith.”

“I actually think it provides an opportunity to reset this relationship, reset these negotiations and get us in a place where Iran can decide not to be a threat to its neighbors, not to be a threat to the United States, and if they’re willing to do that, the United States is all ears,” Vance said.

Rubio said on CBS’s “Face the Nation” that “there are no planned military operations right now against Iran, unless, unless they mess around and they attack” U.S. interests.

Trump has previously threatened other countries, but often backed down or failed to follow through, given his promises to his coalition of voters not to entangle the United States in an extended war. It was not immediately clear whether Iran saw the avoidance of a wider conflict as in its best interests.