U.S.-Pakistan relations are never stress-free. At issue now is whether the U.S. Congress will allow the sale of F-16 aircraft to Pakistan at subsidized rates, if at all. The issue came to the fore when U.S. Secretary of State John Kerry testified before the Senate Foreign Relations Committee on Feb. 23. In a letter to Kerry on Feb. 9, Senator Bob Corker, chairman of the committee, raised strong, initial objections to F-16 sale. He argued that Pakistan has failed to take sufficient action against groups that carry out violent acts outside its borders. By blocking the F-16 sale, the United States sends the wrong signal about Pakistan’s counter-terrorism campaign.