Nuclear Weapons: Comprehensive Test Ban Treaty

A comprehensive test ban treaty, or CTBT, is the oldest item on the nuclear arms control agenda. Three treaties currently limit testing to underground only, with a maximum force equal to 150,000 tons of TNT. According to the Natural Resources Defense Council, the United States conducted 1,030 nuclear tests, the Soviet Union 715, the United Kingdom 45, France 210, and China 45. The last U.S. test was held in 1992 Russia claims it has not tested since 1990. In 1998, India and Pakistan announced several nuclear tests and declared that they were nuclear weapon states each declared a moratorium on further tests, but neither has signed the CTBT. North Korea, which has not signed the treaty, conducted a nuclear test on October 9, 2006. Since 1997, the United States has held 23 subcritical experiments at the Nevada Test Site, most recently on August 30, 2006, to study how plutonium behaves under pressures generated by explosives. It asserts these experiments do not violate the CTBT because they cannot produce a self-sustaining chain reaction. Russia has reportedly held some since 1998, including several in 2000. The U.N. General Assembly adopted the CTBT in 1996. As of October 29, 2007, 177 states had signed it 140, including Russia, had ratified and of the 44 that must ratify the treaty for it to enter into force, 41 had signed and 34 had ratified. Five conferences have been held to facilitate entry into force, most recently in 2007.