Not long ago, I spent an afternoon in a half-empty Cairo café with Ziad el-Elaimy, a left-wing Egyptian lawyer and one of the core group of young activists who helped plan the protests that led to the fall of Hosni Mubarak in 2011. Elaimy was injured by regime thugs in Tahrir Square, and went on to win a seat during the parliamentary elections later that year. He is a remarkable man: insightful, brave, and funny, free of the strident narcissism that afflicts so many self-appointed revolutionaries.

When I asked how he felt about Egypt’s relapse into repression and violence over the past year, he told me that the Egyptian Revolution had begun long before 2011, and would continue long after. He and his friends, he said, had begun imagining a different Arab world a decade ago. They were more aware of the outside world than their parents had been, and less tolerant of the Arab world’s paternalist taboos. “We Arabs grow up with this idea of the Big Man, in religion, in politics, but I think this pattern is now breaking,” Elaimy told me. “We don’t want any more Big Men to tell us what to think. My generation was lucky: we had the Internet, and this helped us discover that the world is bigger than us. That we are not the best, but we must try to be the best. The Revolution was our effort to start that.”

It was inspiring to hear those words, especially from a man who has repeatedly risked his life to defend his democratic principles. But it was painful to be reminded of how much had changed since our first meeting in January 2011. Elaimy and his friends, who were held up for a brief moment as the leaders of a new and more enlightened Arab world, now seem more like outliers. Egypt is once again jailing dissidents, under a new regime—led by the former general Abdel Fattah el-Sisi—that is in some respects more repressive than Mubarak’s. Beyond Egypt’s borders, sectarian hatred is on the rise, and bloody conflicts rage in Libya, Syria, Iraq, and the Gaza Strip. Young people may have made the revolutions of 2011, but they also played a large part in the violence and mayhem that followed. The images of Arab protesters peacefully calling for their rights have faded, and been supplanted by video clips that suggest a wholly different reality: teenage Arab jihadis holding AK-47s and shooting blindfolded prisoners, or burning their passports and declaring allegiance to an “Islamic State” that now lays claim to vast areas of Iraq and Syria.

Was the flowering of liberal Arab youth an illusion? Juan Cole, a prominent liberal blogger and scholar of the Middle East, thinks not.…