The Assad regime has been accused of using chemical agents on rebels and civilians several times over more than six years of civil war in Syria. The first prominent attack came in 2013 in Ghouta, a Damascus suburb—about a year after Barack Obama declared that using such weapons would cross a “red line” and “would change our calculus” about intervening. That attack killed 1,000 people. The latest, on Tuesday in Idlib province, is said to have killed dozens, and came days after Nikki Haley, the U.S. ambassador to the UN, said that America’s “priority is no longer to sit and focus on getting Assad out.”
In the intervening period, the U.S. and Russia formulated an agreement under which Syria agreed to allow international monitors to destroy its chemical-weapons stockpile by 2014, but that deal has apparently done little to deter the continued use of chemical weapons in the conflict.
Syria acknowledged in July 2012 that it possessed chemical weapons, which a foreign-ministry spokesman said would be used only against “external aggression;” a month later, President Obama drew his famous “red line.” There were several reports in the ensuing months of that the Assad regime had used chemical weapons. Then in August 2013, following the Ghouta attack, the U.S. government assessment said it was “highly likely” Assad’s regime was responsible. John Kerry, who was U.S. secretary of state at the time, said the regime used chemical weapons “multiple” times that year. Obama then sought congressional approval for the use of limited military force in Syria. A few days later, Kerry said a military strike could be averted if Syria turned over its chemical weapons to the international community. Russian Foreign Minister Sergey Lavrov proposed such a plan almost immediately—and Syria signed onto it.