Officials say the incident was a model of how Washington often scores its rare victories these days in the fight against al-Qaeda inside Pakistan's national borders: It acts with assistance from well-paid sympathizers inside the country, but without getting the government's formal permission beforehand.

It is an approach that some U.S. officials say could be used more frequently this year, particularly if a power vacuum results from yesterday's election and associated political tumult. The administration also feels an increased sense of urgency about undermining al-Qaeda before President Bush leaves office, making it less hesitant, said one official familiar with the incident.