Nuclear weapon

From Metapedia

A nuclear weapon is an explosive device that derives its destructive force from the nuclear reaction of fission or from a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter; a modern thermonuclear weapon weighing little more than a ton can produce an explosion comparable to the detonation of more than a billion kilograms of conventional high explosive^[1]. The largest nuclear weapon ever detonated, the Tsar Bomba, had a yield of approximately 50 megatons of TNT and even small nuclear devices with yields equivalent to only a few thousand tons of TNT can devastate a city. Because of their extreme destructive power nuclear devices are considered weapons of mass destruction.

In the history of warfare, only two nuclear weapons have been detonated offensively, both by the United States of America during the closing days of World War II. The first was detonated on the morning of August 6, 1945, when the United States dropped a uranium gun-type device code-named "Little Boy" on the Japanese city of Hiroshima. The second was detonated three days later when the United States dropped a plutonium implosion-type device code-named "Fat Man" on the city of Nagasaki. These bombings resulted in the immediate deaths of around 120,000 people from injuries sustained from the explosion and acute radiation sickness, and even more deaths over time from long-term effects of radiation. The use of these weapons was and remains controversial. (See Atomic bombings of Hiroshima and Nagasaki for a full discussion.)

Since the Hiroshima and Nagasaki bombings, nuclear weapons have been detonated on over two thousand occasions for testing purposes and demonstration purposes. The only countries known to have detonated such weapons are (chronologically) the United States, the Soviet Union, the United Kingdom, France, the People's Republic of China, India, Pakistan, and North Korea.

Various other countries may hold nuclear weapons but have never publicly admitted possession, or their claims to possession have not been verified. For example, Israel, who has modern airborne delivery systems and appears to have an extensive nuclear program with hundreds of warheads (see Israel and weapons of mass destruction), officially maintains a policy of "ambiguity" with respect to its actual possession of nuclear weapons. According to some estimates, it possesses as many as 200 nuclear warheads. Iran currently stands accused by the United States of attempting to develop nuclear weapons capabilities, though its government states that its acknowledged nuclear activities, such as uranium enrichment, are for non-weapons purposes. South Africa also secretly developed a small nuclear arsenal, but disassembled it in the early 1990s. (For more information see List of states with nuclear weapons.)

Apart from their use as weapons, nuclear explosives have been tested and used for various non-military uses. Synthetic elements, such as einsteinium and fermium, created by neutron bombardment of uranium and plutonium during thermonuclear explosions, were discovered in the aftermath of the first hydrogen bomb test.