WASHINGTON >> Defense Secretary Jim Mattis took pains today to walk back President Donald Trump’s threats of an imminent strike on Syria, reflecting mounting concerns at the Pentagon that a concerted bombing campaign could escalate into a wider conflict between Russia, Iran and the West.

An afternoon meeting is scheduled today with the president’s top national security advisers, during which Mattis is expected to urge caution and consideration of a wider strategy. Defense Department officials said that will include trying to get more commitments from allies of help immediately after any strikes.

But officials also noted it may be difficult to extricate the Trump administration from military action, given the president’s Twitter post a day earlier that U.S. missiles “will be coming, nice and new and ‘smart.’”

Speaking this morning before the House Armed Services Committee, Mattis said that retaliation for the suspected chemical weapons attack had to be balanced against the threat of a wider war.

“We are trying to stop the murder of innocent people. But on a strategic level, it’s how do we keep this from escalating out of control — if you get my drift on that,” Mattis said.

He added that lawmakers would be notified before any strikes against Syrian weapons facilities and airfields to punish President Bashar Assad’s suspected use of chemical weapons over the weekend. The Pentagon alerted lawmakers before an April 2017 cruise missile attack on Shayrat air base following a similar chemical weapons attack on Syrian civilians.

Trump said he would make a decision “fairly soon” about a strike.

“We’re looking very, very seriously, very closely at that whole situation and we’ll see what happens, folks, we’ll see what happens,” he told reporters at the White House.

“It’s too bad that the world puts us in a position like that,” he said. “But you know, as I said this morning, we’ve done a great job with ISIS,” Trump added, using an alternative name for the Islamic State group. “We have just absolutely decimated ISIS. But now we have to make some further decisions. So they’ll be made fairly soon.”

In a tweet earlier today, Trump insisted that he had never telegraphed the timing of an attack on Syria, and that such a strike “could be very soon or not so soon at all!”

The war train appeared to be moving at a fast clip.

President Emmanuel Macron of France cited unspecified proof that the Syrian government had used chemical weapons in a deadly attack on a suburb of Damascus, the capital. He said that France was working in close coordination with the Trump administration on the issue.

“We have proof that last week, 10 days ago even, chemical weapons were used — at least chlorine — and that they were used by the regime of Bashar al-Assad,” Macron said in an interview on TF1, a French television station.

In London, the British Cabinet had “agreed that the Assad regime has a track record of the use of chemical weapons and it is highly likely that the regime is responsible for Saturday’s attack,” Downing Street said in a statement.

The Cabinet agreed “on the need to take action to alleviate humanitarian distress and to deter the further use of chemical weapons by the Assad regime,” and that Prime Minister Theresa May “should continue to work with allies in the United States and France to coordinate an international response,” the statement said.

British submarines were ordered within missile range of Syria, according to The Daily Telegraph.

The Trump administration has not yet confirmed the use of chemical weapons by the Syrian regime and wants to coordinate its response with allies. But Germany announced that it would not be part of any coordinated military action in Syria, even as Chancellor Angela Merkel stressed the importance of Western powers sending a clear, united message that using chemical weapons “is unacceptable.”

“Germany will not take part in possible military action — I want to make clear again that there are no decisions,” Merkel said after meeting with Lars Lokke Rasmussen of Denmark in Berlin.

Germany refused to take part in the U.S.-led war in Iraq and in 2011 abstained from a U.N. Security Council resolution authorizing the use of military force to protect civilians in Libya.

Trump has previously belittled U.S. leaders for giving the enemy advance warnings of a strike. Heeding Trump’s warning Wednesday about a U.S. response, Syria has moved military aircraft to the Russian base near Latakia and is working to protect important weapons systems.

Russian and Iranian forces are stationed in Syria, ostensibly to support Assad’s fight against Islamic State extremists whom he considers part of the rebellion that has sought to oust him in the country’s seven-year war. The Trump administration’s delay in acting has given the Russians and Iranians more time to prepare for a U.S. strike.

Critics described the contradictory presidential tweets as evidence of the United States’ confusing policy on Syria.

“When the commander in chief speaks publicly about a potential military action, it creates boundaries and limits on what his subordinates can offer him as options,” said Kevin Ryan, a retired Army brigadier general who is now an associate at Harvard’s Belfer Center for Science and International Affairs. “That’s helpful if his public statements are thoughtful and clear. If those statements are confused and unclear, then they are a hindrance to the outcome.”

“I think the latter is happening right now,” Ryan said.

The Thursday afternoon meeting at the White House will be crucial. It will include not only Mattis, but also John Bolton, the new national security adviser who favored strikes against Assad when ordered last year by Trump — but opposed them in 2013 when considered by President Barack Obama.

“In my view the train has left the station,” said Cliff Kupchan, chairman of the Eurasia Group, a political risk consulting and advisory firm. “If Trump now decides not to strike, he’s Obama 2.0 from 2013. That’s the ultimate anathema to President Trump, and I expect him to hit Syria in the next few days.”

Earlier this month, Trump surprised even his own advisers when he said he wanted to immediately withdraw the estimated 2,000 U.S. troops that are currently in Syria, where they are focused on fighting the Islamic State. He softened that demand hours later after a National Security Council meeting, setting a goal of bringing the troops home within a few months.

The suspected chemical weapons attack Saturday, however, enraged the president, and he promised a decision on a U.S. response this week.

In Paris, Macron also said France would continue to push for a cease-fire at the United Nations and for humanitarian aid for civilian populations on the ground to avoid what he described as “the terrible images of crimes that we saw, with children and women who were dying by suffocation, because they were subjected to chlorine.”

“We will have decisions to make in good time, when we decide that it is most useful and most efficient,” Macron said, referring to potential military strikes and adding that any strikes would target the regime’s chemical infrastructure.

The French have warplanes equipped with cruise missiles in Jordan and in the United Arab Emirates, which are within striking range of Syria.

The disjointed messages from the Trump administration could both embolden Assad and dispirit allies that have agreed to support the United States. The president has said “what he was going to do; I think it is important as a nation that we follow through on those things,” Sen. Bob Corker, R-Tenn., said Wednesday on Fox News Radio’s “The Brian Kilmeade Show.” “We’ve waited too long already.”

Nikki Haley, the U.S. ambassador to the United Nations, said “we definitely have enough proof,” of a chemical weapons attack.

“But now we just have to be thoughtful in our action,” Haley told Andrea Mitchell of NBC News.

“I know that the president’s looking at his options and the national security team is trying to give him as many options as we can and we’ll be thoughtful about it and see what happens,” she said.

Asked if the president’s tweets have been helpful, Haley demurred: “Well, I think the president communicates the way he communicates.”

© 2018 The New York Times Company