As thoroughly unpalatable as it is to sit back and watch the horrific murder of innocents without doing something to help, it's difficult to see how a military strike on Syria will do anything to stop the violence, though it would almost certainly add to it, and could realistically help spread it beyond the country's borders. Is making a public moral statement a good enough reason for initiating military action when there's precious little chance of the action contributing to peace? It's a question the United States will have to answer in the coming days.
What to do about Syria? It's a valid question, about which there is no valid answer. Perhaps a better question would be, is there anything we (meaning the developed or civilized world) wants to do? The outside world is neither policeman nor colonizer. Syria wouldn't be the pushover Libya was, and if we became involved it could well boomerang when democracy doesn't occur, and a different tyranny ensues.