This is where Syria comes in. It is stomach-churning for me to suggest that Americans should work to salvage any part of Assad’s regime, which has slaughtered tens of thousands of Syrians. But the least bad option available may be for all powers to pursue two overriding, interlocking goals: Syria’s descent into a total bloodbath must be stopped. And Iran must agree to live up to its nuclear Non-Proliferation Treaty obligations by forswearing atomic weapons.

This does not mean protecting Assad and those close to him. They have to go. But there are generals and other officials from Assad’s Alawite minority who could credibly stay on in a transitional government. U.N. officials have identified a number of them in private contacts with the U.S., French, Russian and other governments, diplomatic sources tell me.

A Syrian coalition that provides physical and political protection for the Alawites and Syria’s other minorities, while reflecting the Sunni majority’s new power, could convince Russia and Iran that they could maintain some influence — however reduced that influence should and would be. (Paradoxically, such a coalition might also quiet Israel’s apprehensions about the strong presence of Islamic jihadists in the rebel movement and exert moderating influence on Egypt’s growing derogation of minority rights.)