The United States should condemn the use of chemical weapons. We should ascertain who used the weapons and we should have an open debate in Congress over whether the situation warrants U.S. involvement. The Constitution grants the power to declare war to Congress not the President.Why should the US even be involved in ascertaining if chemical weapons were used? What if it is determined, one side or the other did use chemical weapons? What then?
The war in Syria has no clear national security connection to the United States and victory by either side will not necessarily bring in to power people friendly to the United States.
As far as I am concerned, bullets, bombs and cruise missiles launched from ships can kill people just as dead as chemical weapons.