But regardless of the state of debate among the U.S. punditry and on the Security Council, there’s no appetite in Western capitals for military action in Syria. That’s not only because how the Libya mission has played out or because of the limited resources Western powers have to devote to expeditionary warfare, today, but also because of the specifics of Syria’s situation.

For one thing, it’s not entirely clear who, in Syria, falls within the rebel camp and who opposes it. Key sectors of the society — whether for reasons of sect or political and economic interest — continue to support the regime. “With no way to know whether a majority supports regime change,” warns Hounshell, “it would hardly be wise to declare al-Assad illegitimate and denounce dialogue with the government as folly without a critical mass of Syrians making it clear they felt the same.”

The opposition is divided and its composition unclear. Western powers alarmed by last week’s debacle in Libya, where the rebels’ military chief appears to have been assassinated by an Islamist militia on his own side, will be wary of suggestions that some of the violence in the Syria rebellion (some 300 members of the security forces are reported to have been killed in its course) is coming from jihadist Syrians who fought in the Sunni insurgency in Iraq.

Even if those specific fears proved to be unfounded, there’s plenty of evidence to suggest a violent component is emerging within the rebellion, and it’s a safe bet that the regime’s brutality will likely intensify armed resistance.