In 1999 Nigerians did something remarkable: they elected a President. After 16 years of military rule and four decades of political and economic failure, Africa's most populous country held a free election. "Globally, things are going democratically," a Lagos slum dweller told the New York Times. "We want to join the globe."
It was a good time to get on board. The percentage of democracies in the world had doubled since the 1970s, to more than 60%. Many of the remaining autocracies--pariah states like North Korea, Burma and Iran--seemed to be living on borrowed time. In ideological terms, as Francis Fukuyama...