U.S. President Donald Trump announced the operation in a Friday night address from the White House and said the military campaign hit targets associated with the chemical weapons capabilities of the regime of Syrian President Bashar Assad.
"The purpose of our actions tonight is to establish a strong deterrent against the production, spread and use of chemical weapons. We are prepared to sustain this response until the Syrian regime stops its use of prohibited chemical agents," said Trump, who had previously called the chemical attack "atrocious" and vowed Syria and its allies Russia and Iran would "pay a price."
He tweeted Saturday that the strikes were "perfectly executed" and declared "Mission Accomplished!"
"The fact of this attack should surprise no-one," British Prime Minister Theresa May said in a statement Friday night. "The Syrian Regime has a history of using chemical weapons against its own people in the most cruel and abhorrent way."
"The red line established by France in May 2017 was crossed," French President Emmanuel Macron said, referring to the use of chemical weapons.
Friday's operation drew strong condemnation from the Syrian regime and its allies. Assad said hours after the strikes that they made his regime even more determined to "fight and crush" terrorism.
Russian President Vladimir Putin denounced the strikes as an "act of aggression" that would have a "destructive influence on the entire system of international relations."
The Kremlin called an emergency meeting of the United Nations Security Council on Saturday, where Russian Ambassador Vassily Nebenzia deplored the attack as "hooliganism," according to a translation by Russian outlet Sputnik News, and said it "makes a catastrophic humanitarian situation worse."
Russian authorities had previously declared that the suspected chemical attack that prompted the strike was staged. At the emergency meeting, French Ambassador François Delattre said French authorities have "no doubt" the attack both occurred and was ordered by Assad's regime.
"We can all see that a Russian disinformation campaign is in full force this morning," U.S. Ambassador Nikki Haley said. "The pictures of dead children were not fake news," she added.
The military strike became necessary after Russia stymied diplomacy by blocking U.N. Security Council action on Syria's chemical weapons six times, Haley said. In the event of future chemical weapons attacks in Syria, she said that Trump had told her "the United States is locked and loaded" to respond.
U.K. Ambassador Karen Pierce outlined four steps to reaching a diplomatic resolution in Syria, including an immediate ceasefire and destruction of chemical weapons stockpiles.
The Security Council later voted to reject a Russian resolution condemning the "aggression" in Syria.
NATO chief Jens Stoltenberg also voiced support of the strike on behalf of all 29 of his members, according to The Associated Press.
Earlier, Iranian Supreme Leader Ayatollah Ali Khamenei called Trump, May and Macron "criminals" in a speech cited by Iranian TV, according to Reuters. "U.S., allies will not gain any achievements from crimes in Syria. Attacking Syria is a crime. U.S. president, U.K. prime minister and the president of France are criminals," he said.
Minutes after Trump's announcement on Friday evening, journalists from Reuters and The Associated Press reported hearing loud blasts over Damascus, the Syrian capital.
The operation started around 9 p.m. EDT and focused on three targets associated with the Syrian regime's chemical weapons program, Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, later confirmed in an evening news conference:
A scientific research center in the greater Damascus area.
A chemical weapons storage facility west of Homs.
A weapons storage facility and a command post close to the facility near Homs.
The strikes "successfully hit every target," Pentagon spokeswoman Dana White said at a briefing Saturday morning. The Syrian military had claimed earlier in the day that it had intercepted "most" of the 105 missiles.
Lt. Gen. Kenneth F. McKenzie said that the U.S. had no indication of civilian casualties and that no aircraft or missiles involved in the operation were successfully engaged by Syrian air defenses.
Friday evening's actions were a response to a chemical weapons attack on the town of Douma, in eastern Ghouta, last Saturday. The attack killed at least 70 people and rebel fighters were forced to relinquish control of the town to forces loyal to Assad shortly after.
Damascus, Moscow and Tehran all deny that the chemical attack was Assad's doing. But Defense Secretary Mattis said Friday that the U.S. had conclusive evidence that chlorine gas was used in the Douma attack. He added the U.S. did not rule out that sarin gas was used as well.
McKenzie said on Saturday that the strikes had crippled the Syrian regime's chemical weapons capabilities, but acknowledged that some of the infrastructure was still left. "I would say there's still a residual element of the Syrian program that's out there," he said. "I'm not going to say that they're going to be unable to continue to conduct a chemical attack in the future. I suspect, however, they'll think long and hard about it."
Tensions With Russia
On Friday, Trump once again called out Assad's backers. "To Iran and Russia I ask, what kind of nation wants to be associated with the mass murder of men, women and children? The nations of the world can be judged by the friends they keep. ... Russia must decide if it will continue down this dark path or if it will join with civilized nations as a source for stability and peace."
Although the Pentagon sought to avoid hitting Russian forces stationed in Syria to prevent a direct confrontation with Moscow, Friday's operation is likely to further escalate tensions between the two countries.
By Saturday, there had been no indication that any Russian forces were hit. And Mattis said the U.S. had not detected any retaliatory action from Russia or Iran.
But the Russian Embassy in the U.S. warned that Friday's strikes "will not be left without consequences." On Saturday, Russian officials on Twitter called the "treacherous and insane" strikes a "clear and present danger to world peace" and demanded accountability.
A One-Time Shot
Trump ordered cruise missile strikes on a Syrian air base almost exactly one year ago following a chemical attack on civilians in the town of Khan Sheikhoun that the U.S. blamed on Assad. Experts said the U.S. retaliation last year did little to deter Assad's campaign against his own people.
U.S. military leaders stressed on Friday that the new operation was much broader in scope and was "a one-time shot" aimed at debilitating Assad's chemical weapons program in the long run.
It remains unclear, however, whether the latest strikes will do much to convince Assad and his powerful supporters that they must reconsider their approach.
While the Pentagon was adamant that the attack significantly decreased Assad's chemical weapons capabilities, Syrian government forces had taken precautions at military bases throughout the week in anticipation of possible strikes. A Syrian official told Reuters on Friday that many of those sites had been evacuated ahead of the attack.
In his efforts to sustain his rule and bring Syria fully under his control, Assad has adopted a winner-take-all strategy that can bear any cost regardless of international condemnation. Just in the past two weeks, more than 1,000 people have been killed in a brutal offensive in eastern Ghouta, according to Doctors Without Borders.
Both Russia and Iran are likely to continue their support of Assad. Their presence deters further international action by raising the prospect of a major escalation.
The chief U.S. partner in the country, the Syrian Kurdish militia known as the YPG, remains uncertain about American intentions. And U.S. work on reconstruction to prevent the return of the self-described Islamic State is ongoing but could stop at any time.
Former President Barack Obama, now remembered for promising military action if Assad crossed the "red line" of using chemical weapons, contemplated a strike in 2013. But Obama sought congressional approval and the strike never happened.
On Friday, before Trump had announced the operation, 88 House lawmakers challenged his legal authority to launch attacks against the Syrian regime without congressional approval. Republican Rep. Justin Amash (Mich.) later called the airstrikes "unconstitutional, illegal and reckless."
Trump had set a path toward retaliation immediately after last Saturday's reports of a chemical attack. "If President Obama had crossed his stated Red Line In The Sand, the Syrian disaster would have ended long ago!" he tweeted the following Sunday. "Animal Assad would have been history!"
Trump's latest action further muddies his own approach to Syria. Just last week, he floated the possibility of imminently withdrawing the 2,000 U.S. troops stationed in the country. His top military advisers, meanwhile, offered a contradictory message, implying that the U.S. still has plenty to do to root out the Islamic State.
Akbar Ahmed, Jesselyn Cook and Sara Boboltz contributed to this report.