The senators who voted for attacking Syria did so without the blessing of the people of the United States. They did so for their own interests not the interest of the people they were elected to represent.
In attacking Assad we give aid and comfort to Al Qaeda and Hezbollah. The extremist sects that fight for the rebels killing and dehumanizing women and minorities in their path. This is an act of treason and unethical.
Even the UN stated an attack would be illegal.