In Pakistan Quandary, U.S. Reviews Stance

By DAVID E. SANGER and DAVID ROHDE

WASHINGTON, Oct. 20 — The scenes of carnage in Pakistan this week conjured what one senior administration official on Friday called “the nightmare scenario” for President Bush’s last 15 months in office: Political meltdown in the one country where Al Qaeda, the Taliban, and nuclear weapons are all in play.

White House officials insisted in interviews that they had confidence that their longtime ally, Gen. Pervez Musharraf, Pakistan’s president, would maintain enough influence to keep the country stable as he edged toward a power-sharing agreement with his main rival, Benazir Bhutto.