I am still unconvinced by the argument for direct U.S. intervention in Syria

As ever, speaking for myself and not my employer.

The New York Times editorial board and Kevin Drum do a good job of laying out the case that the President should seek Congress's approval before going to war in Syria.

In the end, aren't the president's personal convictions all that prevent any military operation from escalating?

It's a fair point, and I'm glad he brought it up. The answer, I think, lies in congressional approval for military action, and this is one of the reasons I think it's so important. If Obama is truly serious about not sending combat troops into ISIS-held areas in Iraq, then let's get a congressional resolution that puts that in writing. Let's get an authorization for war that spells out a geographical area; puts a limit on US troop deployments; and specifically defines what those troops can do.

Would this be airtight? Of course not... But nothing is airtight—nor should it be. It's always possible that events on the ground really will justify stronger action someday. However, what it does do is simple: It forces the president to explicitly request an escalation and it forces Congress to explicitly authorize his request. At the very least, that prevents a slow, stealthy escalation that flies under the radar of public opinion.

Presidents don't like having their actions constrained. No one does. But in most walks of life that deal with power and the use of force, we understand that constraint is important. Surely, then, there's nowhere it's more important than in matters of war and peace. And that's one of the reasons that congressional authorization for war is so essential.

ISIS did heinously execute two Americans that were already in Syria, and they should be punished for that. However, as Zack Beauchamp pointed out, the President implicitly noted that they are not a significant threat to the United States and there is no immediate crisis preventing getting congressional authorization. Syria continues to be an extremely challenging foreign policy problem and as Marc Lynch summarizes, the political science research on the civil wars does not support the idea that we could have just fixed it by intervening to a greater extent:

Would the United States providing more arms to the FSA have accomplished these goals? The academic literature is not encouraging. In general, external support for rebels almost always make wars longer, bloodier and harder to resolve (for more on this, see the proceedings of this Project on Middle East Political Science symposium in the free PDF download). Worse, as the University of Maryland’s David Cunningham has shown, Syria had most of the characteristics of the type of civil war in which external support for rebels is least effective. The University of Colorado’s Aysegul Aydin and Binghamton University’s Patrick Regan have suggested that external support for a rebel group could help when all the external powers backing a rebel group are on the same page and effectively cooperate in directing resources to a common end. Unfortunately, Syria was never that type of civil war.

So put me in the skeptic camp on the benefits of striking Syria. I was less skeptical with the war in Libya, but I take the same position now as I did then: if the President thinks this is a good idea, then take it to Congress. It's in the Constitution for a good reason and there aren't any circumstances that prevent it. Were I in Congress, I'd be inclined to vote no absent notable constraints. However, I'm in the minority there apparently, so what's the harm in asking?