Why not follow the law at will? Keep in mind that every mass atrocity committed by a government was legal at that place and time.
Why not when he bombed Yemen in March?
My point is that if you defer to their rules they set up you are going to be very disappointed to find they already know the loopholes they'll argue let them trample everyone at every turn.
Don't fight on their turf. The bombing is immoral. That is all we should need to know to do all we can figure out to stop them.