Stressed-out cities

LAGOS, Nigeria-It's rush hour in Lagos, the largest city in Africa, where 12-plus million people live in settlements strung out across Nigeria's southwestern coast. Gridlock reigns along the Third Mainland Bridge-at 7.5 miles the longest bridge on the continent. The span connects the mainland with Lagos Island and sends commuters over water where fishing families for centuries have lived in houses on stilts, netting a day's income from wooden canoes visible from the air-conditioned condominiums sprouting on the islands.

It takes an hour to go anywhere here because aging infrastructure fails to keep up with growing urbanization. It's normal to see two or three fistfights a commute, as beefy male drivers lunge from their trucks or cars when sideswiped.

The bridge symbolizes the kind of span city fathers in the world's fastest-growing metropolises face: It reaches Lagos' financial hub where numerous jobs feed a growing middle-to-upper class but passes over those fixed in poverty, earning perhaps $300 a year in menial labor.

Earlier this year the low-boil tension in Lagos exploded when the government tried to eliminate subsidies for fuel. Overnight the price of gasoline doubled-from about 40 to 80 cents per liter in U.S. currency. The city, and most of the country, came to a standstill as millions of protestors took to the streets in opposition to the change. The government's desperate effort to improve its ledger met with public desperation over rising joblessness and soaring prices (inflation in many African nations is spiking near 30 percent this year). One banker told me the streets were so dangerous, she didn't leave her house for a week. Eventually, the government backed down, and a liter of fuel costs now about 60 cents.

Lagos, like other fast-growing cities in Africa and Asia, is perched precariously between economic lift-off and social disintegration. By 2050 economists project Nigeria will be the world's fourth-most-populous nation, and a February report from Renaissance Capital predicted it will overtake South Africa to become the continent's largest economy in just two years.

Abundant resources including an explosion of youth-half the country's population is under age 19-have the potential to drive economic expansion. But as January's fuel protests showed, angry, out-of-work young people can bring a country to its knees.

It's the same in other stressed-out cities-from Cairo to Casablanca and from Dakar to Damascus: The global economic slowdown is hitting the world's undeveloped countries hard. As in Nigeria, a fast-growing population means fewer jobs to go around, large numbers of citizens who've lost jobs in Europe and the United States are returning, and inflation is kicking in just as governments face lowered tax receipts and declining Western aid. Add political upheaval and some terrorism, and it's not hard to see that last year's "Occupy" movements in U.S. cities are but a pale imitation of this year's challenges and the threat of wider unrest.