Pakistan is in crisis. Islamic extremism has metastasized from the lawless tribal areas on the border with Afghanistan to Pakistan's cities. Terrorists tried, and failed, to assassinate the Prime Minister in the capital, Islamabad, on Sept. 3. The nation's economy is a shambles. And Asif Ali Zardari, the man who has just taken the helm of this nuclear-armed country, is a onetime playboy who has spent more time in prison than in government and who wriggled out of a 2006 corruption trial in Britain by pleading mental instability .
The assassination last December of Benazir Bhutto, a former Prime Minister...