Which brings us to the obvious follow-up question: Then what?
The administration appears convinced that President Bashar Assad's government used chemical weapons in a large-scale attack on civilians, crossing a "red line" that President Obama drew some months ago. Even opponents of U.S. involvement in Syria -- including The Times' editorial board -- have acknowledged that the use of chemical weapons is intolerable. In order to deter the use of such toxins, anyone who takes such a desperate step has to suffer consequences.
In Assad's case, though, the only thing he values is his hold on the Syrian government. The same probably could be said of any despot who gasses opponents; it's the tactic of someone desperately clinging to power. That means the only consequence that matters is one that removes that hold.
My colleague Ken Dilanian had an instructive piece Tuesday that underlines this point. The carefully calibrated punishments meted out on despots and terrorists in past years by the United States haven't done much to change their behavior; witness the airstrikes on Iraqi weapons facilities in 1998, which didn't exactly rein in Saddam Hussein. Even former Libyan strongman Moammar Kadafi, who was supposedly scared straight by airstrikes on his living quarters in 1986, was still supporting terrorist attacks such as the one that blew up a commercial airliner over Lockerbie, Scotland.
The United States has gained plenty of experience in deposing governments in recent years, often at an enormous cost for all concerned. And while we've been quite effective when it comes to removing heads of state, we've had mixed results at best when it comes to installing stable replacements.
In Syria, it's conceivable that the United States could limit its response to delivering a blow to Assad's military that's so damaging, he can't hold off the opposition forces. I'm not sure what that would look like, but it might involve a sustained air campaign against Assad's heavy weaponry, air force and air defenses.
Just for the sake of argument, let's assume we could do that and then stand back while Syrian rebels gradually wear down Assad's forces. We would be making a statement about the use of chemical weapons, but in the end, Syria would be taken over by ... who knows? That's one of the reasons the Obama administration has been so hesitant to throw in with the rebels.
And still, if the United States doesn't respond to Assad gassing a rebel city -- should that war crime be confirmed -- what's to stop the next dictator from (literally) putting down the opposition with toxins? Every nation around the globe has an interest in keeping that particularly nasty genie trapped in a bottle, and not just for humanitarian reasons. The more such weapons creep toward respectability, the more they will be produced, which means the easier they will be for terrorists and anti-democratic forces to find through black-market channels.
The death toll from Assad's alleged use of chemical weapons -- about 350, according to Doctors Without Borders -- is a tiny fraction of the German civilians killed when Allied forces in World War II firebombed Dresden, or the Japanese civilians killed by U.S. atomic weapons, or the Jewish civilians killed in Nazi concentration camps. Happily, the world has come to view (and the Geneva Conventions confirm) that civilians are not legitimate targets. The fact that the death toll in Syria hasn't reached the proportions of yore is no reason to shrug it off; doing so would just ensure that the civilian casualties rise.
Nor is it much help to note how many more civilians have died in Syria from conventional weapons. As much as we might like to deter civil wars, the United States' interests really kick in when forces resort to weapons of mass destruction.
So the case for doing something seems clear. What that action should be, however, is anything but.