The Newsweek 50: Gen. Ashfaq Parvez Kayani

In theory this mumbling, chain-smoking general answers to President Asif Ali Zardari. But Kayani and his troops remain the dominant power in what could be the most dangerous country in the world. He's responsible for Pakistan's nukes; for the battle against Al Qaeda and its tribal allies along the Afghan border; and for managing tensions with neighbor India. So far, his army has kept itself out of politics and seems focused on the battle against jihadists. In the wake of the November terrorist attacks in Mumbai, Kayani stood firm on Pakistan's sovereignty while also taking measures against the alleged sponsors of the outrage.

Kayani insists he's a committed democrat, but he nevertheless argues that military interventions (there have been four since independence 61 years ago) are sometimes necessary to maintain Pakistan's stability. He likens coups to temporary bypasses that are created when a bridge collapses on democracy's highway. After the bridge is repaired, he says, then there's no longer any need for the detour.