One of the many geniuses in Gene Rodenberry's Star Trek is the Prime Directive: not to interfere with the development of other races or cultures. This directive is often broken or bent in all the story lines, but that's because the Prime Directive is hard.
Not to interfere in a civil war. Not to interfere in apartheid. Not to interfere in genocide. Not to interfere in holocaust. Not to interfere in ethnic cleansing. Not to interfere in slavery.... it is desperately hard for people of good will to sit by and do nothing when these inhumane events occur. And in fact, we have not yet learned to do so.
Mr. Obama has called for action - limited, targeted action - in Syria. It was clear to me hearing him speak that he believes it to be the right thing to do both as leader of a country and as a man with children. If he gets an authorization through congress, or the UN inspectors prove chemical weapons were used an authorizes action against Assad, then our historical response to atrocities will continue to be military action and intervention. Whether it is a successful action or not will depend on your definition of success.
If nothing happens though, if the people of the world sit back and allow this terrible situation to continue with nothing except humanitarian aid for the refugee and displaced we will have taken a first step toward Rodenberry's Prime Directive and the painful choice of watching misery and allowing people to make their own mistakes, solve their own problems, and end their own wars.
I do not know if this would be better or worse. I do know that it would be different.