The U.S. launched missile strikes on Syria Friday night in coordination with Britain and France in retaliation for Syria’s chemical-weapons attack on civilians last weekend.
President Trump announced the attack in a live televised statement from the White House, saying he had ordered “precision strikes.”
“A combined operation with the armed forces of France and the United Kingdom is now underway,” Mr. Trump said.
The strikes came around 9 p.m. in Washington, 4 a.m. Saturday in Damascus, and targeted three Syrian military installations involved with the use of chemical weapons.
It was the second strike ordered by Mr. Trump in the past year against the forces of Syrian President Bashar Assad to deter his regime’s use of chemical weapons.
Mr. Trump said the military strikes are a response to Syria’s “significant escalation in a pattern of chemical-weapons use” culminating in last weekend’s atrocity in Douma, a rebel-held suburb of Damascus, that killed dozens of civilians. He suggested the allied military action is open-ended.
“The purpose of our actions tonight is to establish a strong determent against the production, spread and use of chemical weapons,” the president said. “Establishing a deterrent is a vital national security interest of the United States. We are prepared to sustain this response until the Syrian regime stops its use of prohibited chemical agents.”
Defense Secretary James N. Mattis and Gen. Joseph F. Dunford, chairman of the Joint Chiefs of Staff, said at 10 p.m. that the first wave of attacks had ended, and no further strikes were contemplated for the moment.
“Right now this is a one-time shot,” Mr. Mattis said. “Right now, we have no additional attacks planned.”
Gen. Dunford said the allies detected the Syrian military firing back with surface-to-air missiles, but there were no initial reported losses among U.S. or allied forces.
Elaborating on the mission, Mr. Mattis said Mr. Trump directed the U.S. military to destroy the Syrian government’s ability to develop and produce chemical weapons.
“Clearly the Assad regime did not get the message last year,” Mr. Mattis said at a Pentagon briefing late Friday night. “This time our allies and we have struck harder.”
Mr. Mattis said the U.S. was “very confident” that Mr. Assad’s forces used chlorine gas in the attack last week, and the U.S. is not ruling out that he also might have used a nerve agent.
Some congressional Democrats said Mr. Trump should have come to Capitol Hill for permission beforehand.
Sen. Tim Kaine, Virginia Democrat and his party’s 2016 vice presidential nominee, called the strike “reckless,” and Sen. Edward Markey, Massachusetts Democrat, said it was “unconstitutional.”
“Absent a robust diplomatic process, military strikes will not change Assad’s calculus regarding the use of chemical weapons against his own people,” he said.
The Trump administration had said it believed it did have the power to conduct the strikes under the 2001 authorization to use force against al Qaeda and other international terrorist groups.
Friday’s attack took place after officials from U.S., France and Britain all expressed certainty that Syrian forces used chemical weapons in the Douma massacre. Syria and its patron, Russia, have denied a chemical attack took place and accused the West of concocting the atrocity.
Top officials in Russia, along with Iran — another prime backer of the Assad government — voiced fears of a wider conflict between the West and Moscow if a military strike hit Syria.
The U.S. has about 2,000 troops in Syria fighting remnants of the Islamic State terrorist group. Russian and U.S. military commanders are in nearly daily contact on a “deconfliction” hotline to avoid misunderstandings and other actions that could bring the two nations’ forces into direct conflict.
CIA Director Mike Pompeo confirmed this week that U.S. forces killed “a couple hundred” Russian mercenary troops in Syria in a strike earlier this year that he said sent a distinct signal to Moscow.
Ships and piloted aircraft were used in the attack, Pentagon officials said. In the strikes against Syria last year, the U.S. military fired only Tomahawk cruise missiles from Navy ships and hit only one target, an air base.
Explosions have been reported near the Syrian capital of Damascus, according to the BBC.
Mr. Trump issued a challenge to Moscow and Tehran in his address, delivered from the Diplomatic Room at the White House.
“I also have a message tonight for the two governments most responsible for supporting, equipping and financing the criminal Assad regime. To Iran and to Russia, I ask: What kind of a nation wants to be associated with a mass-murderer of innocent men, women and children?”
The strikes followed a week of high-level consultations between Mr. Trump, British Prime Minister Theresa May and French President Emmanuel Macron. Mr. Trump also held several meetings with Mr. Mattis and other members of his national security team.
In a statement, Mrs. May said the allied attack is a “limited and targeted strike that does not further escalate tensions in the region and that does everything possible to prevent civilian casualties.”
“This is not about intervening in a civil war. It is not about regime change,” the prime minister said.
She said the West has sought “every possible diplomatic channel” to prevent Syria’s use of chemical weapons in its seven-year-old civil war.
“But our efforts have been repeatedly thwarted,” she said. “So there is no practicable alternative to the use of force to degrade and deter the use of chemical weapons by the Syrian regime.”
Mrs. May said she had signed on to her first military mission since taking office to send a message to Syria and the international community.
“This is the first time as prime minister that I have had to take the decision to commit our armed forces in combat — and it is not a decision I have taken lightly,” she said. “I have done so because I judge this action to be in Britain’s national interest.”
She added, “We cannot allow the use of chemical weapons to become normalized — within Syria, on the streets of the U.K., or anywhere else in our world. We would have preferred an alternative path. But on this occasion, there is none.”
Britain and Russia have been engaged in an angry diplomatic row over the nerve-gas poisoning of an ex-Russian spy last month on the streets of Salisbury, England. Mrs. May’s government says the Kremlin was behind the attack, a charge the Russian government has strongly denied. The attack has led to the expulsion of hundreds of diplomats in Russia, Britain and in a number of Western allies who have sided with London.
Leading up to the military action, some lawmakers had asked Mr. Trump to seek an authorization of military force from Congress; the White House said it would only conduct lawful actions.
Some Republicans urged Mr. Trump even to consider targeting Mr. Assad’s command-and-control operations, including presidential palaces.
Mr. Trump himself had warned Syria and Russia on Twitter Wednesday that missiles “will be coming” soon.
Immediately after the attack was announced, some Republican lawmakers praised the action.
“President Trump is engaged and led our allies in measured response to hold Assad accountable,” said Sen. David Perdue, Georgia Republican and a member of the Senate Armed Services Committee. “Chemical attacks against innocent children and civilians are horrific and totally unacceptable. Assad must know his inhumane actions will not be tolerated. For too long, the world has been asking: When will Assad stop? It is time for action.”
Just two weeks ago, Mr. Trump surprised his military chiefs by voicing publicly his desire to pull all U.S. troops out of Syria, saying the job of defeating the Islamic State was nearly complete.
In his address Friday night, the president seemed intent on reassuring Americans that the military strikes would not lead to a broader and extended U.S. military commitment. He said he is seeking greater contributions from Arab partners in the region to provide security.
“America does not seek an indefinite presence in Syria under no circumstances,” Mr. Trump said. “As other nations step up their contributions, we look forward to the day when we can bring our warriors home. No amount of American blood or treasure can produce lasting peace and security in the Middle East. It’s a troubled place.”
Russia’s ambassador to Washington Friday evening called the allied strike on its ally Syria a “pre-designed scenario” that will be met with a response from the Kremlin.
“Again we are being threatened,” Ambassador Anatoly Antonov said in a Twitter post even as U.S. military officials were outlining the scope and justification for the attack. “We warned that such actions will not be left without consequences.”
The envoy did not detail what the response would be, saying only, “All responsibility for them rests with Washington, London and Paris.”
Russian officials have repeatedly questioned over the past week U.S. and Western claims that the Assad regime had launched the chemical attack, claiming at one point the incident in Douma had been staged by the British government to justify the new allied attack.
‘The U.S., the biggest possessor of chemical weapons, has no moral right to blame other countries,” Mr. Antonov said.
• Stephen Dinan and David Sands contributed to this article.