Definition: A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion.
Types: There are two basic types of nuclear weapons: those that derive the majority of their energy from nuclear fission reactions alone, and those that use fission reactions to begin nuclear fusion reactions that produce a large amount of the total energy output.
History: Starting with scientific breakthroughs made during the 1930s, the United States, the United Kingdom and Canada collaborated during World War II in what was called the Manhattan Project to counter the suspected Nazi German atomic bomb project. In August 1945 two fission bombs were dropped on Japan ending the Pacific War. The Soviet Union started development shortly thereafter with their own atomic bomb project, and not long after that both countries developed even more powerful fusion weapons known as "hydrogen bombs." The world's first nuclear weapons explosion was on July 16, 1945 in New Mexico, when the United States tested its first nuclear bomb. Not three weeks later, the world changed.
On August 6, 1945, the United States dropped an atomic bomb on the Japanese city of Hiroshima. It killed or wounded nearly 130,000 people. Three days later, the United States bombed Nagasaki. Of the 286,00 people living there at the time of the blast, 74,000 were killed and another 75,000 sustained severe injuries. Japan agreed to an unconditional surrender on August 14, 1945; it also resulted in the end of World War II.
In subsequent years, the United States, the Soviet Union and Great Britain conducted several nuclear weapons tests. In 1954, President Jawaharlal Nehru of India called for a ban on nuclear testing. It was the first large-scale initiative to ban using nuclear technology for mass destruction.
In 1958, nearly 10,000 scientists presented to United Nations Secretary-General Dag Hammarskjold a petition that begged, “We deem it imperative that immediate action be taken to effect an international agreement to stop testing of all nuclear weapons.”
France exploded its first nuclear device in 1960 and China entered the "nuclear arms club" in October 1964 when it conducted its first test.
The United States, Soviet Union and some sixty other countries signed a treaty to seek the ends of the nuclear arms race and promote disarmament on July 1, 1968. The treaty bars nuclear weapons states from propogating weapons to other states and prohibits states without nuclear weapons to develop or acquire nuclear arsenal. It permits the use of nuclear energy for peaceful purposes. It entered into force in 1970 and was extended indefinitely and unconditionally on May 11, 1995.
Nations with nuclear weapons
United States, Russia, Britain, France, China, Israel, India, Pakistan, North Korea
Nations hosting nuclear weapons
Belgium, Germany, Italy, Netherlands, Turkey
Nations in nuclear alliances
Albania, Australia, Bulgaria, Canada, Croatia, Czech, Denmark, Estonia, Greece, Hungary, Iceland, Japan, Latvia, Lithuania, Luxembourg, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, South Korea, Spain
The United Nations, on December 12, 1995, decreed an immediate ban on all nuclear testing and urged disarmament with the vision of a world free of nuclear weapons.
Later that month, ten Southeast Asian countries signed the Bankok Treaty, establishing the Southeast Asia Nuclear-Weapon-Free Zone. In Spring 1996, 43 African nations sign the Pelindaba Treaty establishing the African Nuclear-Weapon-Free Zone.
On September 10, 1996, the United Nations, in a landslide vote, adopted the Comprehensive Test Ban Treaty and two weeks later, the United States was the first to sign. (The U.S. Senate, however, rejected the treaty three years later.)
On May 11, 1998, India shocked the world by exploding three nuclear devices amounting to about six times the destructive power of the American bomb dropped on Hiroshima in 1945. The next day, it tested two more nuclear explosions. The world was stunned when Pakistan responded with six nuclear arsenal tests of its own.
World leaders admonished the two long-time adversaries in breaking the Comprehensive Test Ban Treaty (put into force in 1970). The U.S. imposed strict economic sanctions against both countries and lobbied for the World Bank, International Monetary Fund, and other countries to do the same. The sanctions were lifted in 2001 when the U.S. needed Pakistan and India's support to fight al Qaeda and other terrorist cells in Afghanistan.
In 1998 North Korea alarmed Japan by test-firing a medium range-missile (without weapons) over the Japanese mainland. The missile's apparent range, some 1,000 kilometers or 600 miles, meant that any part of Japan -- and by default any part of South Korea -- was within range of North Korean weaponry. Japan is the only country ever to have been attacked by nuclear weapons and anti-nuclear sentiment runs particularly deep.
In 2002, American President George W. Bush named Iran, Iraq and North Korea as the Axis of Evil, in part due to U.S. suspicions of those countries having weapons of mass destruction. Later that year, unofficial reports suggest that North Korea has confirmed the existence of nuclear arsenals, and intelligence reports indicate that the dictatorial power will have enough plutonium to build five or six nuclear bombs by May 2003.
On October 9, 2006 North Korea tested a nuclear weapon with the approximated power of the Hiroshima bomb. North Korea announced to the world that it has become the world's eighth declared nuclear weapons state. Its missiles have the range to hit targets in South Korea, Japan as well as U.S., Chinese, and Russian territories.
The United States is the only known country to have missles with range to attack any target on earth, but over thirty countries have unmanned planes that are undetected by missle defense systems, and can carry nuclear, biological or other weapons of mass destruction.
Waltz: Rational deterrence theory: There is a fundamental difference between conventional and nuclear worlds. Gradual spread of nuclear weapons is better than no spread or rapid spread. Nuclear weapons make war less likely, because nuclear weapons encourage both defense and deterrence. The possibility (however remote) and unacceptably high cost of destruction makes states more careful and miscalculation difficult. Given second-strike capabilities, the balance of forces isn’t what counts – (asymmetric capabilities ok, just a threat ok, credibility need not be proven) Not only do nukes deter attacks on the homeland, they deter attacks on any vital strategic interests, lowers the stakes of war, intensity of war weaker states are not more likely to use nukes irresponsibly – they would lose in a conventional war, so they nee to save their nukes – they will only use them if survival is at stake, not for irresponsible aggression. Even Hitler would have been deterred if Germany had faced nuclear weapons. Even if not, one man can’t make a war – his generals would have stopped him. Madman theory is defunct. The last thing anyone wants to do is make a nuclear nation desperate – so nukes affect the deterrer and the deterred. You can’t totally stop the spread – each state will always strive to seek its own security. Even terrorists are not irrational. Just as unlikely to use nukes as weak states if they do manage to get them.
Sagan: Bureaucratic politics (organizational) theory: Military organizations, unless managed by strong civilian-control institutions, will display organizational behaviors that are likely to lead to deterrence failures and deliberate or accidental war, because of common biases, inflexible routines, and parochial interests. Future nuclear-armed states will likely lack the requisite civilian control mechanisms, and military interests, not objective interests, will dominate talks at length about characteristics of military organizations (offensive culture1 operational culture, etc.. ) and conditions fostering instability (hair trigger alert, inflexible routines that undermine development of second-strike capability) – all of these play into undermining three assumptions/assertions made by Waltz: 1. There must not be preventive war during the period of building nukes, 2. both states must develop second-strike capability and survivability, 3. nuclear arsenals must not be prone to accidental use.