The U.S. led airstrikes in a coordinated attack with U.K. and French allies against the regime of Syrian dictator Bashar Assad.
Here's what we know about the attack:
Precision missile strikes targeted three Syrian chemical weapons facilities: a scientific research center near Damascus, a chemical weapons storage facility west of Homs and a storage facility and command post near Homs. Unleashing 105 missiles, the U.S., British and French forces leveled at least one building and set back the country's chemical weapons program "for years," Pentagon officials said. Trump called it a "perfectly executed strike" in a tweet Saturday.
Gen. Joseph Dunford, the chairman of the Joint Chiefs of Staff said there was some "activity" by Syrian surface-to-air missiles, but there were no reports of U.S. or allied casualties.
When did it take place?
President Trump announced Friday that he ordered the missile strikes, which occurred around 4 a.m. Saturday in Syria. They were a predictable move, considering Trump made threats earlier in the week.
Why did the U.S. strike?
Trump said the strikes were intended to deter the use of chemical weapons like the attack on civilians in the Syrian town of Douma last week.
Syria has denied using chemical weapons. But Friday night, the White House released what it said was "a significant body of information" that pointed to the use of chlorine gas — and possibly also the deadly nerve agent sarin. That evidence includes victim statements, images of barrel bomb fragments and reliable reports of Syrian government helicopters in the area.
Dozens killed in suspected Syria chemical attack
How successful was the mission?
The attack set Syria's chemical weapons program back "for years," Pentagon officials said.
Lt. Gen. Kenneth McKenzie, director of the Joint Staff at the Pentagon, told reporters Saturday that the weapons used in the operation were a mix of sea and air-launched missiles fired by U.S., British and French forces and “successfully hit every target.”
A before-and-after look at the Barzah Research and Development Center:
What are others saying about the attack?
Russian President Vladimir Putin called the airstrikes an “act of aggression” and a “destructive influence on the entire system of international relations." Syria's President Bashar Assad announced that his country would respond, while Russia's ambassador to Washington warned of unspecified "consequences."
British Prime Minister Theresa May said the attack "sends a clear message that the international community will not stand by and tolerate the use of chemical weapons."
What happens next?
Syria's President Bashar Assad announced that his country would respond to the allied attack but offered no details. Russia’s U.S. embassy released a statement warning that the airstrikes will “not be left without consequences.” It said that “all responsibility” rests with Washington, London and Paris.
At an emergency U.N. Security Council meeting Saturday, U.S. envoy Nikki Haley, said the U.S. is "locked and loaded" if the Syrian regime is "foolish enough to test our will." Trump has also said the U.S. is prepared to continue the attacks until the Syrian regime stops using chemical weapons.