"A stable, democratic, economically thriving Pakistan is considered vital to U.S. interests in Asia. Key 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 pivotal 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 traditionally autonomous western tribal areas. A potential Pakistan-India nuclear arms race has been the focus of U.S. nonproliferation efforts in South Asia. Attention to this issue intensified following nuclear tests by both countries in May 1998. The tests triggered restrictions on U.S. aid to both countries (remaining nuclear-related sanctions on Pakistan were waived in October 2001). Pakistan and India have fought three wars since 1947. 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 Issue Brief for Congress, IB94041