feeding jihadi movements is the collapse of effective central governments — a trend in which the West, especially the United States, has been complicit.

An overdue alliance of convenience mobilized against the Islamic State three years ago, but only after leader Abu Bakr al-Baghdadi had taken over enough territory to declare statehood. The ISIS caliphate was as much as a state — for as long as it lasted — as many other places in the Middle East. Most of the coalition members detested ISIS, but only the local members from Iraq and Syria whose families were dying or suffering under Islamic State rule were fully invested. For the rest of the anti-ISIS coalition, fighting the caliphate was one of many other priorities.

The glacial, slow-moving, coalition united against ISIS butTo be sure, the key fighting groups — the Iraqi Kurdish peshmerga, the Shia militias referred to as the Popular Mobilization Units, and the Syrian Kurds from the PKK — are nothing like ISIS. They aspire to political and territorial power without the murderous, nihilistic sectarianism of the Islamic State. At the same time, these groups all profoundly oppose central government in the areas where they live. Some, like the Iraqi peshmerga, want to form a smaller, independent Kurdish republic, even though they are internally divided in a way that promises future strife and civil wars, not harmony. Others, like the Shia militias, want to carve out an autonomous state of their own that functions in the lee of a hobbled central government.

The United States has contributed mightily