This report discusses the current status of Pakistan's nuclear arsenal, which probably consists of approximately 110-130 nuclear warheads. Chronic political instability in Pakistan and Islamabad's military efforts against the Taliban and al-Qaeda have raised concerns about the security of the country's nuclear weapons. Some observers fear that Pakistan's strategic nuclear assets could be obtained by terrorists or used by elements in the Pakistani government; however, U.S. officials have generally expressed confidence in the security of Pakistan's nuclear weapons.