As with World War II, Vietnam, and several dozen other wars and “police actions” in which nothing was actually done to alleviate suffering or prevent massacre, the time for “someone” to easily “do something” in Syria has long, long, long ago come and gone, forever.
Now that the dissidents and protesters have long ago (2+ years) been arrested, tortured, killed and dumped on the streets; now that entire cities (Homs, Aleppo) have been leveled (over a year ago) by the Syrian military, tens of thousands of people snuffed out in a week of heavy artillery; now that criminals and religious fundamentalists have already taken up weapons and can be guaranteed to soon be fighting anyone who wants an actual working government: only NOW the American President and assembled legislature consider whether to “do something”.
The question is no longer a simple choice between doing something — that is, “warfare” — and doing nothing. You have waited too long again. The question has now become: “What hideous, deadly and stupid action will someone be guaranteed to perform and what will the reaction to that hideous, deadly and stupid action be?