No-fly zones might limit the destruction of Assad’s air force, but the Syrian military has other resources at its disposal. Arming the rebels will slightly tilt the battlefield but will not likely break the strategic stalemate or give Washington significant influence within the Syrian opposition. The first step on the slippery slope is always easy, but it’s much harder to actually resolve a conflict or to find a way out of a quagmire.

These painfully familiar arguments about U.S. options miss the point, though. They conceal a prior question: What does it mean for U.S. policy to “work” in Syria? Should Syria be viewed as a front in a broad regional cold war against Iran and its allies or as a humanitarian catastrophe that must be resolved? That question crosses partisan lines and gets to fundamental questions about how to understand the rapidly changing Middle East.

The distinction matters directly and profoundly for the debate over specific policies. Steps that effectively bleed Iran and its allies might well prolong and intensify Syria’s bloodshed, while policies that alleviate human suffering and produce a more stable postwar Syria may well require dealing with Assad’s backers. Imagine that Secretary of State John Kerry brokered a diplomatic breakthrough that ended the fighting and secured a political transition but included an Iranian role — from the latter perspective this would be a stunning success, but from the former it would be an epic disaster.