Continue to have the moral courage to do what is right in Syria

I believe we are a nation that "holds these true to be self evident that all men are created equal, with the right to life liberty and the pursue of happiness". Are there behaviors that are so awful that we feel morally required to become involved? How many people should be gassed before we say "NO!" we are a people will not tolerate such behavior.
It is easy to be morally strong when it is rhetoric and requires no action.
If we have the ability to target the means with which this monster is gassing his own children, I believe we should be brave enough and have the moral courage to act. I hear many say "what is it to us, why should we get involved?" There is minimal self interest other than being the kind of people to live up to the ideals that our country was founded on