However, the proximate issue remains that of upholding the general international consensus not to employ chemical weapons, as established by the Geneva Protocol of 1925 and the 1993 Chemical Weapons Convention. This widely observed arms-control regime is weakened when the Syrian government repeatedly gasses its own citizens after signing on to the Chemical Weapons Convention in 2013.

Western countries have already effectively chosen to ignore the Syrian military’s frequent use of chlorine-gas canisters against rebel-held communities. However, as both the symptoms and the number of fatalities in Douma are suggestive of more lethal chemical agents that the Syrian government supposedly disposed of years earlier, the new violations are harder to overlook.

Sébastien Roblin holds a master’s degree in conflict resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.

Image: Flickr