One year after a Tunisian fruit vendor set himself on fire in an act of defiance that would ignite protests and unseat long-standing dictatorships, a harsh chill is settling over the Arab world. The peaceful demonstrations in Bahrain, Egypt, Libya, Syria and Yemen that were supposed to bring democracy have instead given way to bloodshed and chaos, with the forces of tyranny trying to turn back the clock.

It is too soon to say that the Arab Spring is gone, never to resurface. But the Arab Winter has clearly arrived.

Tunisia, where it all began, recently carried out free elections. But that country — small, ethnically and religiously homogenous, and prosperous — was always a more likely candidate for a successful transition to democracy. Elsewhere in the Middle East, Saudi troops helped orchestrate a crackdown on demonstrators in Bahrain, regime forces gun down protesters in Syria, and Yemen crumbles into civil war, with al-Qaeda running rampant in the countryside. In Libya, we see warlords, Islamists, tribal leaders and would-be democrats vying for power in the post-Gaddafi world. And in Egypt, where the fall of President Hosni Mubarak in February gave us the defining images of the Arab Spring, the military is trying to keep its hands on power.