Bomb or other warhead that derives its force from nuclear fission, nuclear fusion, or both and is delivered by an aircraft, missile, or other system. Fission weapons, commonly known as atomic bombs, release energy by splitting the nuclei of uranium or plutonium atoms; fusion weapons, known as hydrogen bombs or thermonuclear bombs, fuse nuclei of the hydrogen isotopes tritium or deuterium. Most nuclear weapons actually combine both processes. Nuclear weapons are the most potent explosive devices ever invented. Their destructive effects include not only a blast equivalent to thousands of tons of TNT but also blinding light, searing heat, and lethal radioactive fallout. The number of nuclear weapons reached a peak of some 32,000 for the United States in 1966 and some 33,000 for the Soviet Union in 1988. Since the end of the Cold War, both countries have decommissioned or dismantled thousands of warheads. Other declared nuclear powers are the United Kingdom, France, China, India, Pakistan, and North Korea. Israel is widely assumed to possess nuclear weapons. Some countries, such as South Africa, Brazil, Argentina, and Iraq, have acknowledged pursuing nuclear weapons in the past but have abandoned their programs. Seealso Nuclear Non-proliferation Treaty; Nuclear Test-Ban Treaty.
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A Nuclear-Weapons-Free Zone, or NWFZ is defined by the United Nations as an agreement, generally by internationally recognized treaty, to ban the use, development, or deployment of nuclear weapons in a given area. Additionally, this agreement has mechanisms of verification and control to enforce its obligations.
NWFZs are conceived as incremental measures toward total nuclear disarmament, and have steadily grown in number since the first, governing Antarctica. Today, there are eight recognized zones which have been achieved or are in the process of acceptance. Also, some countries have not signed international treaties, but have outlawed nuclear weapons, like Austria with the Bundesverfassungsgesetz für ein atomfreies Österreich in 1999.
|Treaty of Tlatelolco||Latin America and the Caribbean|
|Treaty of Bangkok||ASEAN states|
|Treaty of Pelindaba||Africa|
|Treaty of Rarotonga||South Pacific|
|Central Asian NWFZ||Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan|
|Mongolian NWF Status||Mongolia|
|2+4 Treaty||East Germany|
A difficulty with the Nuclear-Weapons-Free Zone concept is defining suitable zone areas, such that zone neighbours are not considered nuclear threats. For example it was reported in 1996 that no African Arab state will ratify the Treaty of Pelindaba until Israel, which is just outside the zone, renounces its nuclear weapons program; however, Algeria and Libya have since ratified it.