"A stable, democratic, economically thriving Pakistan is considered vital to U.S. interests. U.S. concerns regarding Pakistan include regional terrorism; Pakistan- Afghanistan relations; weapons proliferation; the ongoing Kashmir problem and Pakistan-India tensions; human rights protection; and economic development. A U.S.-Pakistan relationship marked by periods of both cooperation and discord was transformed by the September 2001 terrorist attacks on the United States and the ensuing enlistment of Pakistan as a key ally in U.S.-led counterterrorism efforts. Top U.S. officials regularly praise Islamabad for its ongoing cooperation, although doubts exist about Islamabad's commitment to some core U.S. interests. Pakistan is identified as a base for terrorist groups and their supporters operating in Kashmir, India, and Afghanistan. Since late 2003, Pakistan's army has been conducting unprecedented counterterrorism operations in the country's western tribal areas. The United States reportedly has received pledges from Islamabad that all 'cross-border terrorism' would cease and that any terrorist facilities in Pakistani-controlled areas would be closed. Similar pledges have been made to India. The United States strongly encourages maintenance of a cease-fire along the Kashmiri Line of Control and continued substantive dialogue between Islamabad and New Delhi. Pakistan and India have fought three wars since 1947. A potential Pakistan-India nuclear arms race has been the focus of U.S. nonproliferation efforts in South Asia. Recently, the United States has been troubled by evidence of 'onward' proliferation of Pakistani nuclear technology to third parties, including North Korea, Iran, and Libya. Such evidence became stark in February 2004."
CRS Report for Congress, RL33498