In a security alliance since 2004 and "strategic partners" since 2006, the United States and Pakistan for decades experienced major shifts in the nature and tone of their relations. In the post- 9/11 period, assisting in the creation of a more stable, democratic, and prosperous Pakistan actively combating religious militancy has been among the most important U.S. foreign policy efforts. Vital U.S. interests are seen to be at stake in its engagement with Pakistan related to regional and global terrorism; efforts to stabilize neighboring Afghanistan; nuclear weapons proliferation; links between Pakistan and indigenous American terrorism; Pakistan-India tensions and conflict; democratization and human rights protection; and economic development. As a haven for numerous Islamist extremist and terrorist groups, and as the world's most rapid proliferator of nuclear weapons, Pakistan presents a combination that places it at the top of many governments' international security agendas.