The Arab Spring is often celebrated by reciting the roll call of overthrown autocrats. But revolutions, in the end, will be judged primarily by what they build, not what they destroy. And in this respect, a year of revolution has refashioned exhilaration into paradox. The United States applauded the demonstrations in Egypt’s Tahrir Square. Blaming itself for too protracted an association with an undemocratic leader, it urged Hosni Mubarak to step down. But once he did so, the original exultant demonstrators have not turned out to be the heirs. Instead, Islamists with no record of democracy and a history of hostility to the West have been elected to a presidencythey had pledged not to seek. They are opposed by the military, which had buttressed the previous regime. The secular democratic element has been marginalized. Where do we go from here?