Bashar al-Assad is losing ground in Syria

For most of the past two years, it looked like Bashar al-Assad's campaign to hold on in Syria was working. Syria's weak, uncoordinated, and increasingly Islamist rebels were being gradually pushed back. And while ISIS had seized vast parts of the country, it and Assad appeared to tolerate one another in a sort of tacit non-aggression pact designed to crush the Syrian rebels. It seemed that Syria, and the world, would be stuck with Assad's murderous dictatorship for the foreseeable future.

But in the past few weeks, things appear to...