How far will Trump go in Syria?

US President Donald Trump has deepened America’s commitment to the war in Syria with Saturday’s multinational missile strikes in response to President Bashar al-Assad’s alleged use of chemical weapons in the conflict.

It’s still unclear how far Trump is willing to expand America’s involvement in the war, but the positive response to the strikes among domestic commentators and considering Trump’s own political troubles with mid-term elections on the horizon point to a possible intensified campaign.

The Trump administration said its strikes, conducted in cooperation with France and the United Kingdom, were launched in response to Syrian President Bashar al-Assad’s use of chemical weapons, including a suspected April 7 attack at the town of Douma that killed up to 75 people.

Western officials claimed the 105-missile attack, including on a scientific research and development center in the capital of Damascus’ Barzeh district and two facilities nearly the city of Homs, had crippled Assad’s chemical weapons abilities. Trump tweeted simply “Mission Accomplished” after the missile strikes.

“We believe that by hitting Barzeh in particular we’ve attacked the heart of the Syrian chemicals weapon program,” US Lieutenant General Kenneth McKenzie said at the Pentagon after the attacks, according to Reuters.

McKenzie also acknowledged elements of the program remain and he could not guarantee that Syria would be unable to conduct a chemical attack in the future, reports said.

Other Trump administration officials said the attacks came in response to Assad’s use of the chemical agents chlorine and perhaps even sarin, an extremely lethal nerve agent banned in warfare by international conventions.

“A large body of information indicates that the Syrian regime used chemical weapons,” US ambassador to the United Nations Nikki Haley told the United Nations Security Council on Saturday, according to reports.

The use of sarin triggered Trump’s decision last year to strike a Syrian air base. A sarin attack in 2013 on civilian populations also nearly brought then-US President Barack Obama to attack Syria. Syria’s debilitating civil war started in 2011.

Chlorine has been used more widely in Syria’s conflict without US, UK or French reprisals, and the chemical itself is far easier to find and weaponize, Reuters reported citing experts.

That, reports said, will make it more difficult to degrade or eliminate stocks of chemical weapons through remotely launched missile strikes. The Syrian government has consistently denied it uses chemical weapons.

It remains unclear if another chemical weapons attack using chlorine gas would be enough to motivate more US attacks or if Saturday’s bombardments were the first phase of a planned longer campaign against Assad’s regime.

The Trump administration made threats in the latter direction on Saturday. Defense Secretary Jim Mattis said he was only certain about intelligence that chlorine gas was used by Assad’s forces on April 7 before America’s strikes on Syria.

Vice President Mike Pence also said Trump carried out the strikes armed with U.S. intelligence that at “a minimum it was the chemical weapon of chlorine,” noting investigators still might prove sarin was used.

A different Trump administration official, briefing reporters, said the US assessed that sarin was also used in the April 7 attack but suggested that US information on sarin came from analysis of reports from news media and other public sources of information, as opposed to US intelligence, news agencies reported.

Trump indicated he thought sarin had been used when he said on Twitter on Wednesday that US missiles “will be coming” and accused Assad of being a “Gas Killing Animal.”

The US, UK and France are already deeply involved in Syria’s grinding war by arming rebels, bombing Islamic State fighters and deploying troops on the ground to fight that particular militant group.

But to date they have largely refrained from targeting Assad’s Russia-backed government, apparently to avoid a wider geopolitical conflict. Syria and its allies said they considered the attack a one-off show of force that was unlikely to undermine Assad’s position.

That may or may not be the case. The UN’s Organization for the Prohibition of Chemical Weapons (OPCW) said in an inquiry that the Syrian government used sarin in an April 4, 2017, attack and has used chlorine as a weapon on several occasions.

The inquiry ended in November after Russia blocked three attempts by the UN Security Council to renew its mandate to continue its investigations. Moscow had said the joint UN and OPCW inquiry was riddled with errors.

US ambassador Haley said at the UN Security Council on Friday that any military intervention by the Trump administration would not be in response to just the latest attack at Douma.

“The United States estimates that Assad has used chemical weapons in the Syrian war at least 50 times. Public estimates are as high as 200,” she said, according to reports.

She hinted on Saturday that the US would launch new strikes if Assad continued to use chemical weapons, but stopped short of specifying which chemical agent would warrant fresh attacks.

“If the Syrian regime uses this poison gas again, the United States is locked and loaded. When our president draws a red line, our president enforces the red line,” Haley said.

[This report draws on news agency reporting]