Al-Qaeda remains committed to striking the United States, but its capacity has been limited by counterterrorism efforts and so might work with or through associated Pakistani outfits to launch an attack. Some Pakistani groups could also strike unilaterally or collaborate with one another on an attack. A successful attack would severely test already strained U.S.-Pakistan relations, which could have negative repercussions for various regional initiatives, especially U.S. efforts in Afghanistan. In this latest Center for Preventive Action Contingency Planning Memorandum, Stephen Tankel outlines policy tools that U.S. decision-makers can employ to prevent an attack and to mitigate the consequences if one occurs. Tankel recommends, among other steps, that these officials increase efforts to build counterterrorism capacity among Pakistan's civilian law enforcement and intelligence agencies, restructure how the United States provides aid to the country's military, and develop a campaign plan that accounts for a range of Pakistani responses in the event of a potential attack.