The dual disruption offers potential new opportunities to ferret out and target the extremists, and it has sparked a new sense of possibility amid a generally pessimistic outlook for the conflict in Afghanistan and Pakistan. Although al-Qaeda remains “a serious, potent threat,” a U.S. counterterrorism official said, “they’ve suffered some serious losses and seem to be feeling a heightened sense of anxiety — and that’s not a bad thing at all.”

The offensive in Swat against its Taliban allies also poses a dilemma for al-Qaeda, a senior military official said. “They’re asking themselves, ‘Are we going to contest’ ” Taliban losses, he said, predicting that al-Qaeda will “have to make a move” and undertake more open communication on cellphones and computers, even if only to gather information on the situation in the region. “Then they become more visible,” he said.