WASHINGTON — For a decade, President Trump promised to end what he calls forever wars, casting himself as a leader opposed to prolonged conflicts in the Middle East and who would rather pursue peace in the world.

Now, early in his second term, Trump is taking military action against Iran that could expand well beyond a limited effort to halt the country’s nuclear program.

In a video posted on Truth Social, the commander in chief said American forces also plan to “raze their missile industry to the ground” and “annihilate their navy.” He warned members of Iran’s military to surrender or “face certain death.” And urged the Iranian people to take the moment as an opportunity to rise up against their government.

“This regime will soon learn that no one should challenge the strength and might of the United States armed forces,” Trump said.

A few hours after relaying that message, Trump confirmed in a separate social media post that Ayatollah Ali Khamenei, the supreme leader of Iran, was among those killed by U.S. and Israeli strikes. Even with his death, Trump said that “the heavy and pinpoint bombing” would continue in Iran “as long as necessary to achieve our objective of PEACE THROUGHOUT THE MIDDLE EAST AND, INDEED, THE WORLD!”

Trump, who has been considering a strike on Iran for several weeks, acknowledged he reached the decision to attack Iran while aware of the human toll that could come with it.

“The lives of courageous American heroes may be lost, and we may have casualties. That often happens in war,” he said. “But we are doing this, not for now, we are doing this for the future, and it is a noble mission.”

Trump’s military campaign in Iran is a sharp turn in tone for a president who has long been critical of open-ended conflicts in the Middle East, and marks a shift from an America-first agenda message that helped him return to the White House.

“I’m not going to start a war. I’m going to stop wars,” Trump said in his November 2024 victory speech as he promised to focus national resources on domestic priorities rather than foreign conflicts.

As Trump advocated to bring home American forces from deployments around the world and to withdraw from key defense treaties, his position resonated with a war-weary electorate in the lead-up to the election.

Fewer than six in 10 Americans (56%) believed the United States should take an active role in world affairs ahead of the election — the second-lowest level recorded since the question was first asked in 1974, according to polling by the Council on Foreign Affairs.

Trump’s posture on war in the Middle East had been largely consistent before he ran for office.

In 2013, he criticized then-President Obama’s negotiations with Tehran, predicting in a post on Twitter that Obama would “attack Iran because of his inability to negotiate properly.” That same year, Trump warned that “our horrendous leadership could unknowingly lead us into World War III.”

And in a heated February 2016 debate, Trump attacked former Florida Gov. Jeb Bush, stating that his brother George W. Bush lied about Iraq’s nuclear capabilities to get the U.S. into the Iraq war. Trump called the Iraq war a “big, fat mistake” that “destabilized the Middle East.”

“They lied. They said there were weapons of mass destruction. There were none, and they knew there were none,” he said.

At the time of the Iraq war, however, Trump had said he supported it.

Trump’s confrontation with Iran bears little resemblance to his earlier rebukes.

Trump has yet to present evidence of an imminent threat to the United States from Iran’s nuclear program — a capability he claimed to have “obliterated” just eight months ago — and has instead framed the military campaign as one to ensure Tehran never develops nuclear weapons at all.

“It is a very simple message,” he said. “They will never have a nuclear weapon.”

Trump’s shift has already drawn the attention of congressional Democrats, many of whom are calling the president out for backing out on his promise to end foreign wars — and are demanding that he involve Congress in any further military actions.

“Regardless of what the President may think or say, he does not enjoy a blank check to launch large-scale military operations without a clear strategy, without any transparency or public debate, and not without Congressional approval,” Sen. Alex Padilla (D-Calif.) said.

Sen. Adam Schiff (D-Calif.) criticized Trump for “drawing the country into yet another foreign war that Americans don’t want and Congress has not authorized.”

The military involvement in Iran is not the first time that members of Congress have complained about the Trump administration’s willingness to sideline the legislative branch on decisions that could trigger broader conflicts this year.

In January, Trump ordered military forces to capture former Venezuelan President Nicolás Maduro and said the United States would run the sovereign nation until further notice. He threatened military action in Colombia, whose leftist President Gustavo Petro has been one of Trump’s most vocal critics.

Trump has alienated allied nations when he said he was willing to send American troops to seize Greenland, a semiautonomous territory of Denmark. And on Friday, he said U.S. is in talks with Havana and raised the possibility of a “friendly takeover of Cuba” without offering any details on what he meant.

His actions have coincided with his annoyance at not being awarded the Nobel Peace Prize. At one point, the president said he no longer felt an “obligation to think purely of Peace” because he didn’t get the recognition.

Trump’s shifting tone, and his use of violent war imagery in his pretaped remarks about Iran, have rattled even part of his base.

“I did not campaign for this. I did not donate money for this,” said former Rep. Marjorie Taylor Greene, a conservative who recently left Congress after a bitter fight with Trump. “This is not what we thought MAGA was supposed to be. Shame!”

Republican leaders, however, are largely standing behind the president.

Senate Majority Leader John Thune (R-S.D.) said Iran “posed a clear and unacceptable threat” to the United States and has refused “the diplomatic off-ramps.” House Speaker Mike Johnson (D-La.) said Trump took the action after exhausting “every effort to pursue peaceful and diplomatic solutions.”

Other top Republican lawmakers rallied behind Trump, too.

“The butcher’s bill has finally come due for the ayatollahs,” Sen. Tom Cotton, the chairman of the Senate Intelligence Committee, wrote in a post on X. “May God bless and protect our troops on this vital mission of vengeance, and justice, and safety.”