In the quiet streets of Khan Sheikhun, people mourned the dead from a sarin attack, bracing for the next raid. At an airbase near Homs, government warplanes roared back into action, their targets unknown. And not far from his golf course in south Florida, the president of the United States cried out a defense on Twitter.

“The reason you don’t generally hit runways,” Donald Trump wrote, “is that they are easy and inexpensive to quickly fix (fill in and top)!”

The president’s exclamation followed a more formal justification of his decision to launch 59 missiles at a Syrian government airbase on Thursday, the first direct attack by the US against Bashar al-Assad after six years of civil war.

Trump sent Congress a letter invoking war powers as the authority behind his order, saying the strike was directed “in the vital national security and foreign policy interests” of the United States.

The missiles were meant “to degrade” Assad’s ability to conduct chemical weapons attacks, Trump wrote, and “to dissuade the Syrian regime from using or proliferating chemical weapons”.

On Saturday, with the airbase in action, warplanes killed a woman and injured one other person in Khan Sheikhun, monitoring groups said. It was not immediately clear where the planes came from, although the Syrian government and its Russian allies are the only airforces operating in the area.

It was also reported by monitoring groups that air strikes killed at least 18 people including five children in Urum al-Joz, another town in Idlib province, on Saturday. The toll was expected to rise.

The casualties were a bloody reminder that while Trump may have redrawn the US red line on chemical weapons use, there have been no clues to his views on the wider conflict.

The president remained in Florida on Saturday, playing golf and praising the US armed forces. “Congratulations to our great military men and women for representing the United States, and the world, so well in the Syria attack,” he wrote on Twitter.

A satellite image provided by DigitalGlobe shows the Shayrat air base in Syria, following US missile strikes. Photograph: AP

In Washington, uncertainty reigned over what step, if any, Trump will take next to build on the momentum from the missile strikes. His team has cast the strikes, which targeted the base used to launch the sarin that fell on Khan Sheikhun on Tuesday, as a contained response to the specific horror of chemical weapons.

But Trump’s sudden reversal – from months of stated opposition to foreign entanglements to a dramatic attack, decided over some 60 hours – makes it far from clear whether he is in favour of isolation or intervention.

“I am flexible, and I’m proud of that flexibility,” he said this week.

A ‘one-time strike’?

Just prior to the chemical attack, Trump’s top diplomats were describing Assad’s continued rule as “political reality”. The administration has since ducked questions about whether Trump believes Assad should leave power.

“I think, first and foremost, the president believes that the Syrian government, the Assad regime should, at the minimum, agree to abide by the agreements that they made not to use chemical weapons,” press secretary Sean Spicer said on Friday, declining to comment on future plans.

“He’s not going to telegraph his next move,” he added.

The only strategy the White House was willing to discuss publicly was additional economic sanctions, overseen by Steven Mnuchin, the treasury secretary.

It is time for all civilised nations to stop the horrors that are taking place in Syria and demand a political solution Nikki Hayley, UN ambassador

The Pentagon has indicated that there are no further plans to move against Assad as the war against Islamic State and other extremists continues, although Nikki Haley, ambassador to the United Nations, did not rule out going beyond the “very measured step” of this week’s strike.

“We are prepared to do more,” she told an emergency meeting of the UN security council. “But we hope that will not be necessary. It is time for all civilised nations to stop the horrors that are taking place in Syria and demand a political solution.”

In Washington, Gen Joseph Dunford, chairman of the joint chiefs of staff, held a closed-door meeting with senators on Friday afternoon, apparently on the complexity of the brutal conflict.

The US and European nations have resisted direct intervention so far in part because Assad is fighting a fractured opposition dominated by Islamists, many of whom dream of creating a Sunni theocracy. Moreover, the chaos that engulfed Iraq and Libya after the overthrow of autocratic rulers haunts any proposal to remove the president from power.

“We don’t have the benefit of a larger strategy,” senator John Cornyn of Texas told reporters after the session with Dunford. “Is our goal just to defeat Isis or is our goal to change the regime, and if there is policy to change the regime what comes next?”

Republican senators John McCain and Lindsey Graham, who have long advocated decisive action in Syria, called for “a new, comprehensive strategy” to end the Syrian conflict, including safe zones and more support for the “vetted opposition”. .

“The first measure in such a strategy,” they said, “must be to take Assad’s air force – which is responsible not just for the latest chemical weapons attack, but countless atrocities against the Syrian people – completely out of the fight”.

‘It had a big impact on me’

Trump’s decision to launch missile strikes was apparently driven by a visceral reaction to images from the scene of the chemical attack, including photographs of young children foaming at the mouth and lifeless babies on the ground.

“It had a big impact on me,” he told reporters this week.

For rebel groups who have for years demanded more international support in the fight against Assad, the US missile strikes brought limited relief.

Opposition activists said they were happy that at least one brutal weapon had apparently been declared off limits, but pointed out that most of the tens of thousands of civilian victims of the war had died in conventional attacks.

“Ameera Skaf was killed by Assad and Russian warplanes in Doma today,” said activist Abdulkafi al Hamdo, sharing pictures of a toddler he said had been killed on Friday by pro-government forces.

“Not only chemical [weapons] kills our children.”

Still, some said they hoped that now Trump had revised his position on Assad, he might be persuaded to intervene further.

Turkey is among voices calling on the US to push Assad to leave office, and Ankara has supported rebels even while fighting Kurdish factions opposed to Assad.

“If this intervention is limited only to an airbase, if it does not continue and if we don’t remove the regime from heading Syria, then this would remain a cosmetic intervention,” said foreign minister Mevlüt Çavuşoğlu, speaking in the southern city of Antalya.

In a sign of how the chemical weapons attack has roiled the region, the influential Iraqi Shia cleric Moqtada al Sadr, the leader of a militia that fought the US occupation of Iraq,also called for Assad to step down.

“I would consider it fair for President Bashar al-Assad to resign and leave power, allowing the dear people of Syria to avoid the scourge of war and terrorist oppression,” he said in a statement. He also demanded Washington and Moscow disengage from the civil war.

Russia’s support for Assad and military presence on the ground is the biggest question hanging over Trump’s options for action in Syria. The greatest fear is that miscalculation could bring the two nuclear-armed powers into direct conflict.

Russia has threatened to suspend a hotline the militaries share to avoid accidental clashes in Syria, but US officials have disputed claims that it was already cut off. Meanwhile, a Russian warship equipped with cruise missiles arrived to join a battlegroup off the coast of Syria.

Rex Tillerson, Trump’s secretary of state, is set to travel to Moscow this week for a critical meeting. He has condemned Russia’s support for “a regime that carries out these types of horrendous attacks on their own people”. Tillerson spoke to his counterpart, Sergei Lavrov, on Saturday. Lavrov and other Russian officials have said the US strike was unjustified and that the US has not shown evidence of Assad’s culpability, despite his past use of chemical weapons.

