For Obama administration officials, that’s a source of deep anxiety — and frustration. Pakistan is at the center of U.S. hopes to turn around the flagging Afghan war, but persistent anti-American feelings limit the extent of Pakistani cooperation. On her visit to Pakistan last month, Secretary of State Hillary Rodham Clinton mused that Americans must wonder “why we’re sending money to a country that doesn’t want it.”

Pakistanis insist they are not ungrateful. They just don’t see any tangible impact from the massive sums the United States spends. Unlike assistance from decades ago, the money from the post-Sept. 11 era, Pakistanis say, tends to vanish without a trace.

“Everyone here hates the American government,” said Shah, a spirited 71-year-old with a stark white beard and a sharp tongue. “I haven’t seen a penny of this U.S. assistance.”

Analysts say there are many reasons: poor coordination with the Pakistani government, a lack of understanding of Pakistan’s needs and a reluctance to produce iconic projects, lest they become targets for terrorists.