President Donald Trump ordered missile strikes in Syria on Thursday evening, just days after a deadly chemical weapons strike that the United States attributed to the Assad regime.

More than 50 Tomahawk cruise missiles were launched toward an airbase near Homs, Syria, from ships in the eastern Mediterranean, according to Pentagon spokesman Capt. Jeff Davis.

“On Tuesday, Syrian dictator Bashar al-Assad launched a horrible chemical weapons attack on innocent civilians using a deadly nerve agent. Assad choked out the lives of helpless men, women, and children,” Trump said from his Mar-a-Lago Resort in Florida. “Tonight, I ordered a targeted military strike on the airfield in Syria from where the chemical attack was launched. It is in the vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons.”

The Pentagon said targets included aircraft, petroleum and logistical storage, ammunition supply bunkers, air defense systems, and radars.

A U.S. official told The Daily Beast the punitive strikes had a “good effect” on target. The official spoke on the condition of anonymity in order to describe the initial reports of the aftermath of the strikes.

Pentagon spokesman Davis said the U.S. intelligence community believes aircraft from Shayrat Airfield conducted the chemical weapons attack on Tuesday. Thursday’s strikes occurred at Shayrat Airfield at 8:40 p.m. Eastern, or approximately 4:40 a.m. in Syria.

“Initial indications are that this strike has severely damaged or destroyed Syrian aircraft and support infrastructure and equipment at Shayrat Airfield, reducing the Syrian government’s ability to deliver chemical weapons,” Davis said. “The use of chemical weapons against innocent people will not be tolerated.”

“Tonight, I call on all civilized nations to join us in seeking to end this slaughter and bloodshed in Syria and also to end terrorism of all kinds and all types. We ask for God’s wisdom as we face the challenge of our very troubled world,” Trump said. “We pray for the lives of the wounded and for the souls of those who have passed, and we hope that as long as America stands for justice, then peace and harmony will in the end prevail.”

Trump made the announcement Thursday night surrounded by top aides: Steve Bannon, Reince Priebus, Ivanka Trump, Dina Powell, Wilbur Ross, and numerous others. He read off two teleprompters, stuck to prepared remarks, and answered no questions before leaving the stage.

Trump had previously been a critic of proposed military action against the Assad regime in 2013, arguing that it was costly and that President Obama required congressional approval to make the strike. The aerial bombing in Idlib province Tuesday, which the United States has attributed to the Syrian regime, appeared to have swayed Trump to take military action.

“That attack on children yesterday had a big impact on me—big impact,” he said on Wednesday. “It crossed a lot of lines for me. When you kill innocent children, innocent babies… that crosses many, many lines, beyond a red line. Many, many lines.”

Secretary of State Rex Tillerson, who a week before had hinted the U.S. could tolerate Bashar al-Assad staying in power in Syria, stepped in line, telling the press that plans were already under way to organize an international coalition to remove Assad.

“Assad’s role in the future is uncertain, clearly, and with the acts that he has taken, it would seem that there would be no role for him to govern the Syrian people,” Tillerson said. “The process by which Assad would leave is something that I think requires an international community effort—both to first defeat ISIS within Syria, to stabilize the Syrian country, to avoid further civil war, and then to work collectively with our partners around the world through a political process that would lead to Assad leaving.”

U.S officials have radar-derived intelligence confirming that Syrian regime aircraft dropped munitions on the town at the time of the attack in Idlib.

Officials believe it was “some kind of chemical but do not yet have high confidence that it was sarin,” one of the officials said, referring to the deadly nerve agent. The second official said their main source of information on the suspected sarin attack is images provided by the World Health Organization of the victims.

Republican hawks, who have typically been critics of the president, were quick to praise his decision.

“Unlike the previous administration, President Trump confronted a pivotal moment in Syria and took action. For that, he deserves the support of the American people,” said Sens. John McCain and Lindsey Graham after the strikes had been reported.

Earlier Thursday, former presidential candidate Hillary Clinton gave Trump political cover, calling on the United States to take out Assad’s air force—a more aggressive action than what Trump ordered Thursday evening.

“Assad has an air force, and that air force is the cause of most of these civilian deaths, as we have seen over the years and as we saw again in the last few days,” Clinton said. “And I really believe that we should have and still should take out his air fields and prevent him from being able to use them to bomb innocent people and drop sarin gas on them.”

But elected Democrats wary of giving Trump a blank check were more reserved. Sen. Ben Cardin, the top Democrat on the Senate Foreign Relations Committee, praised the strikes but said any continued action would require congressional buy-in.

“These military strikes against Assad’s arsenal send a clear signal that the United States will stand up for internationally accepted norms and rules against the use of chemical weapons,” Cardin said. “However, and I cannot emphasize this enough, any longer-term or larger military operation in Syria by the Trump administration will need to be done in consultation with the Congress.”

No contacts were made with the Russian government, Tillerson told the press late Thursday night at a briefing with reporters at the Tideline Hotel in Palm Beach, Florida. However, military deconfliction agreements between U.S. and Russian forces were used to prevent misunderstanding.

“The one thing that I will tell you, though: There was an effort to minimize risk to third country nationals at that airport—I think you read Russians from that—we took great pains to try to avoid that. Of course, you know, anytime in a military operation, there are no guarantees,” he said.

The U.S. Navy destroyers USS Ross and USS Porter fired the Tomahawks from the eastern Mediterranean. Ross and Porter are both Arleigh Burke-class guided missile destroyers that can carry up to 90 missiles apiece in vertical launch tubes. The subsonic Tomahawk missiles fly pre-planned routes to blast fixed targets as far as 1,000 miles away with their 1,000-pound warheads.

It’s not hard to see why the Pentagon chose Tomahawks for Thursday’s strikes. The military has deployed hundreds of manned warplanes in the Middle East, including F-22 stealth fighters. B-2 stealth bombers based in Missouri can fly direct to Syria drop precision-guided bombs. But the Pentagon apparently balked at sending pilots into western Syria.

“There were three options we discussed with the president, and the president asked us to focus on two options in particular, to mature those options, and he had a series of questions for us that we endeavored to answer,” National Security Adviser H.R. McMaster told the press Thursday evening.

Military planners made the same call in September 2014, when the United States first began hitting ISIS forces in Syria. For strikes on militants in western Syria, the Pentagon opted to send Tomahawks instead of manned planes. While the Israeli air force—among the best-trained in the world—frequently bombs regime positions in western Syria, other air forces are wary of the risk.

“Of all the Middle Eastern nations, Syria has one of the most robust [surface-to-air missile] networks,” wrote Sean O’Connor, an independent air-defense expert based in Indiana. “Multiple SAM sites provide redundancy, allowing for overlapping coverage in many critical areas,” including population centers.

Damascus has upgraded its mostly Soviet-era missiles with Chinese technology, making them nimbler and more independent—and thus harder to destroy. “With modern Chinese radars and modern Russian SAMs [Syria] has moved away from the bomb-able model of air defense,” O’Connor wrote.

In addition to its own air-defense missiles, the Syrian regime enjoys the protection of long-range S400 and S300 missiles that Moscow deployed to its air base in Latakia and the port of Tartus, respectively.

It’s not clear whether Russia forces had authorization to defend against an American attack on Moscow’s ally in Syria. But the Tomahawk strike risked directly striking Russian forces and forcing Moscow’s hand. The main target, Shayrat Airfield outside Homs, recently hosted Russian attack helicopters supporting Syrian ground forces operating in the area.