Nuclear, Biological, and Chemical Weapons and Missiles: Status and Trends [Updated July 2, 2004] [open pdf - 497KB]
"The United States has long recognized the dangers of nuclear, biological, and chemical (NBC) weapons, and missiles proliferation. Despite the preeminence of U.S. military power, or perhaps because of it, these weapons continue to pose threats to the United States and its foreign interests. NBC weapons could be delivered by means ranging from simple options (e.g., ships, trucks), to aircraft, cruise or ballistic missiles. The total number of NBC weapons in the world is shrinking as the major powers scale back their inventories through unilateral reductions and arms control, but other countries and groups still try to acquire these weapons. Especially since September 11, 2001, U.S. and allied leaders have debated the nature and extent of the threat, the impact on international stability, and the opportunities terrorists might exploit. The number of nuclear arsenals worldwide is small. There are the established nuclear weapon states (China, France, Russia, the United Kingdom, and the United States), while India, Pakistan and Israel are believed to have nuclear weapon arsenals. North Korea is thought to have separated enough plutonium for at least one or two weapons, and possibly six. Iran is considered by U.S. intelligence to be pursuing a nuclear weapons program, and international inspections have revealed significant strides in its nuclear fuel cycle capabilities."
CRS Report for Congress, RL30699