By JOHN T. BENNETT and BRIDGET BOWMANCQ Roll Call

In an abrupt policy reversal, President Donald Trump on Thursday evening ordered missile strikes on a Syrian air base after that country’s embattled regime carried out a deadly sarin gas attack that killed dozens of civilians.

As recently as late last week, Trump’s top Cabinet-level foreign policy officials signaled the new administration would drop its predecessor’s policy that Syrian President Bashar al-Assad would eventually have to relinquish power. Then came images on Tuesday of children and infants killed in the gas attack, which Trump himself admitted a day later had changed his thinking about Assad and Syria.

“Using a deadly nerve agent, Assad choked out the lives of helpless men, women and children. It was a slow and brutal death for so many,” Trump said Thursday night from his Florida golf resort, where he is holding meetings with his Chinese counterpart.

“Even beautiful babies were cruelly murdered in this very barbaric attack. No child of God should ever suffer such horror,” he said. “Tonight, I ordered a targeted military strike on the airfield in Syria from where the chemical attack was launched.”

Trump decision to use force came remarkably early for a new president, just shy of his 80th day in office. The Trump administration informed senior members of Congress of the military action in Syria while it was underway, according to a congressional aide.

The 70 or so cruise missiles he fired at what appears to be the Shayrat airbase, from where the administration believes the sarin attack was launched, represented a departure — perhaps temporary — from his “America first” approach to governing.

On Tuesday, the populist, domestic-focused president firing cruise missiles into another sovereign country seemed far-fetched.

“I’m not — and I don’t want to be — the president of the world,” Trump told a builders’ union conference that day. “I’m the president of the United States. And from now on, it’s going to be America first.”

But the Assad regime’s brutality, at least for now, has altered Trump’s approach.

[Trump Seems Increasingly Resigned to US Action in Syria]

Still, House Intelligence Committee ranking member Adam Schiff, D-Calif., called Trump’s shift “a very abrupt change of course” in “just a few days.” He told MSNBC that senior Trump administration officials mere days ago “said basically it’s up to the Syrian people to decide who will remain the leader of Syria as if the Russians, the Iranians and Hezbollah weren’t involved.”

The Democratic Party’s 2016 vice presidential candidate, Tim Kaine of Virginia, went so far as to label the U.S. strike “unlawful” because the White House did not seek Congressional authorization.

Missiles a deterrent?

The president cast his decision not solely as a response to Assad’s latest use of chemical weapons, saying the strikes also were meant to “prevent and deter the spread and use of deadly chemical weapons.”

“It is in this vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons,” he said. “There can be no dispute that Syria used banned chemical weapons, violated its obligations under the Chemical Weapons Convention, and ignored the urging of the UN Security Council.”

In further explaining his decision, he appeared to take yet another jab at former President Barack Obama, who in the late summer of 2013 opted against military action in Syria after a previous Assad chemical attack.

“Years of previous attempts at changing Assad’s behavior have all failed and failed very dramatically,” Trump said, going on to say that “as a result, the refugee crisis continues to deepen, and the region continues to destabilize, threatening the United States and its allies.”

However, the military action contradicts Trump’s urging Obama in 2013 stay out of the troubled Middle Eastern country. Trump fired off a Sept. 5, 2013 tweet as Obama mulled his options that ended with this suggestion: “Do NOT attack Syria,fix U.S.A.”

The only reason President Obama wants to attack Syria is to save face over his very dumb RED LINE statement. Do NOT attack Syria,fix U.S.A.

— Donald J. Trump (@realDonaldTrump) September 5, 2013

That same year, in another tweet, he said it would be a “big mistake” if the 44th president acted without lawmakers’ approval.

The President must get Congressional approval before attacking Syria-big mistake if he does not!

— Donald J. Trump (@realDonaldTrump) August 30, 2013

Regardless of whether Congress ever passes a new measure authorizing Thursday night’s — and possibly future — strikes inside Syria, the U.S. attack creates instant risks for the new commander in chief.

Michael McFaul, a former U.S. ambassador to Russia, warned that Assad could respond by again using chemical weapons on his own people.

Trump biggest worry now; what if Assad defies him and uses chemical weapons again?

— Michael McFaul (@McFaul) April 7, 2017

Quick reaction

Reaction from Capitol Hill, where as of late afternoon leaders of national security committees had yet to be briefed that strikes were imminent, was swift.

Lawmakers on both sides of the aisle had called on Trump to respond to the chemical attack in Syria with a call for Syrian President Bashar al-Assad to step down. They have also called on Trump put forth a clear strategy for addressing the conflict.

As news broke of the action, both Democrats and Republicans offered support for the military action. But they also made sure to call for a more comprehensive U.S. strategy in Syria, and for the administration to engage with Congress on that strategy.

Schiff, who was called by Director of National Intelligence Dan Coats shortly after the missiles were launched from U.S. Navy ships, said the White House has no “intention to have more than this single strike,” but he added the administration “is reserving their options depending on whether the regime responds against our troops or takes any other action against U.S. targets or allies.”

The Trump administration consulted Foreign Relations Committee Chairman Bob Corker before the use of military force, according to an aide for the Tennessee Republican. Sen. Benjamin L. Cardin, the top Democrat on the committee, was informed of the strikes while they were underway.

Corker praised the action as “a proportional step,” and Cardin said they sent ” clear signal that the United States will stand up for internationally accepted norms and rules against the use of chemical weapons.” Both senators called for the administration to consult with Congress on any longer term strategy.

The second-highest ranking Senate Democrat, Richard J. Durbin of Illinois said in a statement that the action was a “measured response” to the chemical attack. He is the top Democrat of the Appropriations Subcommittee that allocates funding for the Defense Dept.

The top Senate Democrat, Charles E. Schumer of New York, applauded the move, saying in a statement that “making sure Assad knows that when he commits such despicable atrocities he will pay a price is the right thing to do.‎” But Schumer, like other lawmakers, said it is now “incumbent on the Trump administration to come up with a strategy and consult with Congress before implementing it.”

[Taunting Trump: Pelosi Challenges POTUS to Prove Claims]

Speaker Paul D. Ryan, R-Wisc., called the strikes “appropriate and just,” adding in a statement that “these tactical strikes make clear that the Assad regime can no longer count on American inaction as it carries out atrocities against the Syrian people.”

Senate Armed Services Chairman John McCain, R-Ariz., said in a joint statement with Sen. Lindsey Graham R-S.C., also called for a new Syria strategy.

“The first measure in such a strategy must be to take Assad’s air force — which is responsible not just for the latest chemical weapons attack, but countless atrocities against the Syrian people — completely out of the fight,” they said.

The actions did spur some lawmakers to join Kaine’s call that such use of military force must be approved by Congress.

“While we all condemn the atrocities in Syria, the United States was not attacked,” said Sen. Rand Paul, R-Ky. “The President needs Congressional authorization for military action as required by the Constitution, and I call on him to come to Congress for a proper debate. Our prior interventions in this region have done nothing to make us safer and Syria will be no different.”

Congress has previously declined to take up a measure authorizing the use of military force against the Islamic State terror group, with leaders arguing an AUMF passed after the Sept. 11, 2001 terrorist attacks also applies to actions against ISIS.

And House Minority Leader Nancy Pelosi, D-Calif., called the move “a proportional response,” but added a major caveat: “If the president intends to escalate the U.S. military’s involvement in Syria, he must to come to Congress for an authorization for use of military force which is tailored to meet the threat and prevent another open-ended war in the Middle East.”

Rep. Tulsi Gabbard, D-Hawaii, who, in a controversial move, met with Assad on a fact-finding trip in January, described the missile attack as an escalation that was “shortsighted and will lead to more dead civilians, more refugees, the strengthening of al-Qaeda and other terrorists.”

She even suggested that it could lead to “a possible nuclear war between the United States and Russia.”

“This Administration has acted recklessly without care or consideration of the dire consequences of the United States attack on Syria without waiting for the collection of evidence from the scene of the chemical poisoning,” Gabbard said in a statement Thursday night. “If President Assad is indeed guilty of this horrible chemical attack on innocent civilians, I will be the first to call for his prosecution and execution by the International Criminal Court. However, because of our attack on Syria, this investigation may now not even be possible.”

Other lawmakers took their reactions to Twitter:

#bigmistake pic.twitter.com/u3xFXrTR6m

— Thomas Massie (@RepThomasMassie) April 7, 2017

I support @POTUS airstrike on Syria’s Shayrat Air Base. A limited strike designed to send a message to Assad and a few others.

— Rep. Mark Walker (@RepMarkWalker) April 7, 2017

Lindsey McPherson contributed to this report.