Soon after al-Bab, a rural town just north of Aleppo, was liberated from the Assad regime in the summer, citizens and off-duty Syrian rebels took to the streets and started cleaning up. They swept the sidewalks in the absence of any municipal sanitation, picking up chunks of concrete rubble left over from a punishing artillery assault that had ended just days earlier. For four decades, anything spontaneous required permission from the regime. This was an assertion of individual autonomy against a totalitarian state—destructive creation as its noblest.

The...