New tests for Macron and May with first major military operations

A spokeswoman said: “The prime minister welcomed the public support which had been given by fellow world leaders for the strong stand the UK, France and the United States had taken in degrading Syria’s chemical weapons capability and deterring their use; defending global rules; and sending a clear message that the use of chemical weapons can never become normalised.”

For May, whose time in office has been consumed by extracting her country from the European Union, the Syria crisis presents a new headache.

British involvement in military interventions abroad is controversial in a country still haunted by its role in the 2003 US-led invasion of Iraq.

“There is no graver decision that a prime minister can take than to send service personnel into combat. It is a decision that I have not taken lightly,” May told reporters on Saturday.

British lawmakers voted down taking military action against Damascus in 2013, in what was widely viewed as an assertion of parliamentary sovereignty on the use of force.

But in an earlier statement Saturday, May said there was “no practicable alternative to the use of force”, insisting it had been “right and legal” to go ahead, and without consulting MPs.

A YouGov poll in The Times newspaper conducted this week found that 43 percent of voters oppose strikes in Syria, with 34 percent unsure and only 22 percent supportive.