U.K.'s Boris Johnson defends airstrikes in Syria

Britain's Foreign Secretary Boris Johnson has written an editorial outlining the reasoning behind the Syrian airstrikes.

Johnson wrote in the Sunday Telegraph that the military operation by the U.S., France and the U.K. may not end "sick barbarism," but shows "we stand up for principle and civilized values."

The missile strikes, he said, were intended to send a message that the use of chemical weapons won't be tolerated.

The airstrikes early Saturday were launched in response to the suspected use of chemical weapons in Douma, in eastern Ghouta, near the capital Damascus.

Johnson wrote about intelligence that suggests the Syrian regime was behind events in Douma, which led to airstrikes on three sites alleged to be part of President Bashar al-Assad's chemical weapons program

A number of witnesses reported seeing a helicopter circling over Douma during the suspected gas attack last weekend.

In a statement on Saturday, the White House said multiple government helicopters were observed in the area the day it's believed toxic gas was unleashed.

Aid organizations and activists say the bombardment began April 6 with the use of barrel bombs and continued the next day with the use of chemical weapons, leaving dozens of people killed or injured.

"Vile, sick, barbaric though it is to use such weapons — that is not the principal objection. These munitions are not just horrible. They are illegal," Johnson said.

Labour leader Jeremy Corbyn has described the strikes on three sites alleged to be part of Assad's chemical weapons program as "legally questionable."

Others in the U.K. opposition have criticized the lack of a parliamentary vote before the airstrikes were launched. Johnson said U.K. Prime Minister Theresa May would address such criticism when parliament reconvenes on Monday.

Johnson, appearing on the BBC's The Andrew Marr Show on Sunday, said he hoped the action would act as a deterrent to the Syrian regime and would, at the very least, stem "the continual erosion of the taboo against chemical weapons."

Russia is a key ally to Assad's regime in Syria and fiercely protested against the airstrikes.

A Russia-tabled resolution condemning the strikes was voted down by the UN Security Council on Saturday, with only China and Bolivia voting in favour.