A dramatically new approach to chemical weapon use in Syria should be seriously considered:
Rather than using only legal argument and political agreement bases for military attack, I recommend considering massive international shaming of those who have used such weapons, presumably Assad. Such an approach should be based upon all the moral bases the world espouses, especially those included in the Quran, Bible and Torah and other traditions. This would be a tidal shift in global public consciousness, presumably putting us all on the same page.
I see mostly an upside to consequences and virtually no downside. Such shaming should be started by a simultaneous "full court press" by the world's clergy, political leaders, academics and medical ethicists (Assad is an ophthalmologist) as well as some ordinary people who have experienced the weapons directly.
Especially, in the Middle East and Asia, shaming and saving face have long culture histories. Let us promote this cultural approach. This also could be a game changer, a new, powerful tool for international diplomacy, as a principle, assuming there has been full, factual substantiation for weapons of mass destruction having been used.