There is a notion of Cairo, and of Egypt, in which its residents have long sought refuge. Unlike other Arab countries, their borders drawn with imperial whim, lines too straight on a map to make sense, Egypt is a true nation, and Cairo a true capital. Celebrated is the sense of its unity.
When the revolution began last winter, the prevailing wisdom in Cairo was that Egypt, imbued with so much history, could navigate change by virtue of its homogeneity, shared culture, ferocious pride and reverence for its past.
But the capital that Hosni Mubarak left behind after he was toppled in February is...