Their ascendancy is not new; for a generation, they have eclipsed their secular and leftist predecessors, whom they often act (and sometimes speak) like. But the legacy of their virtual monopoly on opposition is becoming more and more clear. They have reinterpreted conflicts — between Arab and Israeli, East and West — and have highlighted the degree to which the very notion of identity has shifted in the Arab world; so much so that “Arab” may soon become passé in defining that world. And with a politics bereft of ideology beyond faith, they have narrowed the avenues for change in a region whose inhabitants desperately want it.

These movements often exude a canny pragmatism. Islamists in Turkey, Egypt, Lebanon and the Palestinian territories have all embraced electoral success; in time, they may even reinforce a democratic body politic. But on issues from poverty to Palestine, they have imposed a paradigm of morality, ethics and occasional absolutism that tends to neglect society’s most pressing problems or turn them into unrequitable anthems.

This is a large reason that for reformers, provocateurs and critics outside their orbit, pessimism is the fashion today. “Religious politics or politicized religion has taken over,” said Fawwaz Traboulsi, a historian, columnist and longtime leftist activist from Lebanon. Asked if there was any counterexample out there — beyond the quixotic fringes and uncompromising idealists — he shook his head.

“No,” he said, “I don’t think there is.”

The American University of Beirut hosts a collection of hundreds of posters from an age that was violent, tumultuous but, to many in the region, more capable of hope that solutions for the region’s deep problems could be found. They are eclectic, from the agitprop of secular Palestinian groups to the intoxicating promises of Lebanese partners bent on abolishing the nation’s vaguely feudal system a generation ago.

Many are imbued with the iconography of the third world liberation movements of the day. (Read: ample imagery of the Kalashnikov rifle.) The haircuts date the photos. So do the terms. (“Armed struggle,”rather than today’s preferred “jihad.”) But they capture a fervent idealism. To the West, it may have been the era of the massacre at Munich, hijackings and the rise of Yasir Arafat’s Palestine Liberation Organization. But to many Arabs, it was a time pregnant with the promise of real change, when the Palestinian movement captured the Arab imagination to a degree unmatched before or since.