The United States fired cruise missiles on Friday at a Syrian airbase from which it said a deadly chemical weapons attack had been launched this week, the first direct US assault on the government of Bashar al-Assad in six years of civil war.
US President Donald Trump ordered the attack his predecessor Barack Obama never did. The attack directly targetting Assad's military with air strikes, was prompted by the chemical weapons attack, which killed at least 70 people, many of them children.
That put the United States into a confrontation with Russia, which has military advisers on the ground assisting its close ally Assad.
"Years of previous attempts at changing Assad's behaviour have all failed and failed very dramatically," Trump said as he announced the attack from his Florida resort, Mar-a-Lago, where he was meeting Chinese President Xi Jinping.
"Even beautiful babies were cruelly murdered in this very barbaric attack," he said of Tuesday's chemical weapons strike, which Western countries blame on Assad's forces. "No child of God should ever suffer such horror."
The Syrian army said the US attack killed six people at its air base near the city of Homs. It called the attack "blatant aggression" and said it made the United States a "partner" of "terrorist groups" including Islamic State. Homs Governor Talal Barazi told Reuters the death toll was seven.
A spokesman for Russian President Vladimir Putin said the strike had seriously damaged ties between Washington and Moscow. Putin, a staunch ally of Assad, regarded the US action as "aggression against a sovereign nation" on a "made-up pretext", spokesman Dmitry Peskov said.