Instruct: Given a question, retrieve relevant documents that answer the question.
Query: When were nuclear weapons first used in war?
So far, two nuclear weapons have been used in the course of warfare, both by the United States near the end of World War II. On August 6, 1945, a uranium gun-type device (code name "Little Boy") was detonated over the Japanese city of Hiroshima. Three days later, on August 9, a plutonium implosion-type device (code name "Fat Man") was detonated over the Japanese city of Nagasaki. These two bombings resulted in the deaths of approximately 120,000 people.
Through 2008, the United States repeatedly refused to rule out using nuclear weapons in an attack on Iran. The U.S. Nuclear Posture Review made public in 2002 specifically envisioned the use of nuclear weapons on a first strike basis, even against non-nuclear armed states. Investigative reporter Seymour Hersh reported that, according to military officials, the Bush administration had plans for the use of nuclear weapons against "underground Iranian nuclear facilities". When specifically questioned about the potential use of nuclear weapons against Iran, President Bush claimed that "All options were on the table". According to the "Bulletin of the Atomic Scientists", Bush "directly threatened Iran with a preemptive nuclear strike. It is hard to read his reply in any other way." The Iranian authorities consistently replied that they were not seeking nuclear weapons as a deterrent to the United States, and instead emphasize the creation of a nuclear-arms free zone in the Middle East. The policy of using nuclear weapons on a first-strike basis against non-nuclear opponents is a violation of the US Negative Security Assurance pledge not to use nuclear weapons against non-nuclear members of the nuclear Non-Proliferation Treaty (NPT) such as Iran. Threats of the use of nuclear weapons against another country constitute a violation of United Nations Security Council Resolution 984 and the International Court of Justice advisory opinion on the Legality of the Threat or Use of Nuclear Weapons.
The triad gives countries a way to deliver a nuclear attack by land, sea or air. For the United States, the idea to have these three options was for the purpose of retaliation. If two of the three legs of the triad were destroyed, the third could still have a retaliatory strike. Also, having these three legs protects against the issue of new technology, like an enemy missile-defense system. It also gives the commander-in-chief the flexibility to use different types of weapons for the appropriate strike while also maintaining a reserve of nuclear weapons safe from a counter-force strike.Tactical nuclear weapons, also known as non-strategic nuclear weapons, are used in air, land and sea warfare. Their primary use in a non-strategic war-fighting role is to destroy military forces in the battle area. But, depending on the target in today's nuclear age, they are not counted toward triad status because of the possibility that many of these systems could be used as strategic weapons. During the Cold War, it was easy to point out which nuclear weapons were tactical. Each type of weapon had different capabilities that were better suited for different missions. Air-to-air missiles, rockets, surface-to-air missiles, small air-to-ground rockets, bombs, and precision munitions have been developed and deployed with nuclear warheads. Ground forces have included tactical nuclear artillery shells, surface-to-surface rockets, land mines, medium and small man-packable nuclear engineering demolition charges, and even man-carried or vehicle-mounted recoilless rifles. Naval forces have carried weapons that include nuclear-armed naval rockets, depth charges, torpedoes, and naval gunnery shells.
Of the three nuclear powers in NATO (France, the United Kingdom and the United States), only the United States has provided weapons for nuclear sharing. , Belgium, Germany, Italy, the Netherlands and Turkey are still hosting US nuclear weapons as part of NATO's nuclear sharing policy. Canada hosted weapons until 1984, and Greece until 2001. The United Kingdom also received US tactical nuclear weapons such as nuclear artillery and Lance missiles until 1992, despite the UK being a nuclear weapons state in its own right; these were mainly deployed in Germany.
In 1999, the Kargil War between India and Pakistan became the first direct conflict between two declared nuclear powers. As the war progressed, the first hint of the possible use of a nuclear weapon was on 31 May, when Pakistani foreign secretary Shamshad Ahmad made a statement warning that an escalation of the limited conflict could lead Pakistan to use "any weapon" in its arsenal. This was immediately interpreted as an obvious threat of a nuclear retaliation by Pakistan in the event of an extended war. The leader of Pakistan's senate noted that "the purpose of developing weapons becomes meaningless if they are not used when they are needed." Some experts believe that following nuclear tests in 1998, Pakistani military was emboldened by its nuclear deterrent cover to markedly increase coercion against India.
As both India and Pakistan are armed with nuclear weapons, the possibility a conventional war could escalate into a nuclear one was raised several times during the standoff. Various statements on this subject were made by Indian and Pakistani officials during the conflict, mainly concerning a no first use policy. Indian External Affairs Minister Jaswant Singh said on 5 June that India would not use nuclear weapons first, while Musharraf said on 5 June he would not renounce Pakistan's right to use nuclear weapons first. There was also concern that a 6 June 2002 asteroid explosion over Earth, known as the Eastern Mediterranean Event, could have caused a nuclear conflict had it exploded over India or Pakistan.
The UK has not declared a no first use policy regarding launching a nuclear attack; former British defence secretary Geoff Hoon stated in 2002 and 2003 that the UK would be willing to attack rogue states with them if nuclear weapons were used against British troops. In April 2017 Defence Secretary Michael Fallon confirmed that the UK would use nuclear weapons in a "pre-emptive initial strike" in "the most extreme circumstances". Fallon stated in a parliamentary answer that the UK has neither a 'first use' or 'no first use' in its nuclear weapon policy so that its adversaries would not know when the UK would launch nuclear strikes. 
Research into the development of nuclear weapons was initially undertaken during World War II by the United States (in cooperation with the United Kingdom and Canada), Germany, Japan, and the USSR. The United States was the first and is the only country to have used a nuclear weapon in war, when it used two bombs against Japan in August 1945. After surrendering to end the war, Germany and Japan ceased to be involved in any nuclear weapon research. In August 1949, the USSR tested a nuclear weapon, becoming the second country to detonate a nuclear bomb. The United Kingdom first tested a nuclear weapon in October 1952. France first tested a nuclear weapon in 1960. The People's Republic of China detonated a nuclear weapon in 1964. India conducted its first nuclear test in 1974, which prompted Pakistan to develop its own nuclear program and, when India conducted a second series of nuclear tests in 1998, Pakistan followed with a series of tests of its own. In 2006, North Korea conducted its first nuclear test.
The United States insists that its forces control the weapons and that no transfer of the nuclear bombs or control over them is intended "unless and until a decision were made to go to war, at which the NPT would no longer be controlling", so there is no breach of the NPT. However, the pilots and other staff of the "non-nuclear" NATO countries practice handling and delivering the US nuclear bombs, and non-US warplanes have been adapted to deliver US nuclear bombs which involved the transfer of some technical nuclear weapons information. Even if the US argument is considered legally correct, some argue such peacetime operations appear to contravene both the objective and the spirit of the NPT. Essentially, all preparations for waging nuclear war have already been made by supposedly non-nuclear weapon states.
Prescient stories about nuclear war were written before the invention of the atomic bomb. The most notable of these is "The World Set Free", written by H. G. Wells in 1914. During World War II, several nuclear war stories were published in science fiction magazines such as "Astounding". In Robert A. Heinlein's story "Solution Unsatisfactory" the US develops radioactive dust as the ultimate weapon of war and uses it to destroy Berlin in 1945 and end the war with Germany. The Soviet Union then develops the same weapon independently, and war between it and the US follows. The bombing of Hiroshima and Nagasaki in 1945 made stories of a future global nuclear war look less like fiction and more like prophecy. When William Faulkner received the Nobel Prize in Literature in 1949, he spoke about Cold War themes in art. He worried that younger writers were too preoccupied with the question of "When will I be blown up?"
A tactical nuclear weapon (TNW) or non-strategic nuclear weapon is a nuclear weapon, generally smaller in its explosive power, which is designed to be used on a battlefield in military situations, mostly with friendly forces in proximity and perhaps even on contested friendly territory. This is in contrast to strategic nuclear weapons which are designed to be mostly targeted in the enemy interior away from the war front against military bases, cities, towns, arms industries, and other hardened or larger-area targets to damage the enemy's ability to wage war. Tactical nuclear weapons were a large part of the peak nuclear weapons stockpile levels during the Cold War.
By the 1960s Okinawa was known as "The Keystone of the Pacific" to U.S. strategists and as "The Rock" to U.S. servicemen. Okinawa was critical to America's Vietnam war effort where commanders reasoned that, "without Okinawa, we cannot carry on the Vietnam war."
During U.S. involvement in the Vietnam War the use of nuclear weapons was suggested in order to "defoliate forests, destroy bridges, roads, and railroad lines." In addition, the use of nuclear weapons was suggested during the planning for the bombing of Vietnam's dikes in order to flood rice paddies, disrupt the North Vietnamese food supply, and leverage Hanoi during negotiations. Each of the cold war plans employing a U.S. launched nuclear first strike were ultimately rejected.
Nuclear weapons brought an entirely new and terrifying possibility to warfare: a nuclear holocaust. While at first the United States held a monopoly on the production of nuclear weapons, the Soviet Union, with some assistance from espionage, managed to detonate its first weapon (dubbed "Joe-1" by the West) in August 1949. The post-war relations between the two, which had already been deteriorating, began to rapidly disintegrate. Soon the two were locked in a massive stockpiling of nuclear weapons. The United States began a crash program to develop the first hydrogen bomb in 1950, and detonated its first thermonuclear weapon in 1952. This new weapon was alone over 400 times as powerful as the weapons used against Japan. The Soviet Union detonated a primitive thermonuclear weapon in 1953 and a full-fledged one in 1955.
Powell rejected the viewgiven by successive British governmentsthat nuclear weapons deterred Russia from conquering the countries of Western Europe and that as these nuclear weapons were mainly American, that British security rested on "the American alliance and American armament". Powell believed that even if Russia had wanted to, they would not have dared to invade Western Europe "for one simple overwhelming reason: it would have meant a war they couldn't expect to win" against the United States. Powell asserted that the nuclear deterrent was "a pretend deterrent". Powell argued that the existence of separate nuclear weapons for France and Britain demonstrated that they believed that the United States would not risk a nuclear war over Western Europe, and that therefore they were "victims to their own reasoning" as neither France nor Britain would themselves use nuclear weapons in the event of an invasion because the consequences of nuclear war would be too horrific. Powell also disagreed with the notion that nuclear weapons protected Britain from blackmail since Britain would have to choose between "unlimited devastation" from nuclear weapons or surrender.
Italy started hosting US nuclear weapons under NATO's nuclear sharing policy. The first nuclear weapons deployed were MGR-1 Honest John and MGM-5 Corporal rockets in 1957. and were later followed by the MIM-14 Nike Hercules surface-to-air missile. However, all these systems were under sole US control and so Italy simultaneously pursued dialogue with other European nations on a collaborative nuclear programme. Discussions were held with France and Germany about a joint nuclear deterrent, but these were curtailed in 1958 by Charles de Gaulle's desire for an independent French deterrent.
The decision by Switzerland on 23 December 1958 to pursue a nuclear weapons programme put an additional impetus on Italy. Pressure was made on the United States to provide additional nuclear weapons. On 26 March 1959, agreement was made that the Italian Air Force would receive 30 PGM-19 Jupiter ballistic missiles to operate from Gioia del Colle Air Base. The first missiles arrived on 1 April 1960. This time the American provided a dual-key system that led the Italian government to believe they had greater control over the deterrent and thus more power in NATO. Explicitly, the new missiles could be used "for the execution of NATO plans and policies in times of peace as well as war". The missiles were operated by a new brigade, the 36ª Aerobrigata.
China became the first nation to propose and pledge NFU policy when it first gained nuclear capabilities in 1964, stating "not to be the first to use nuclear weapons at any time or under any circumstances". During the Cold War, China decided to keep the size of its nuclear arsenal small rather than compete in an international arms race with the United States and the Soviet Union. China has repeatedly re-affirmed its no-first-use policy in recent years, doing so in 2005, 2008, 2009 and again in 2011. China has also consistently called on the United States to adopt a no-first-use policy, to reach an NFU agreement bilaterally with China, and to conclude an NFU agreement among the five nuclear weapon states. The United States has repeatedly refused these calls.
The United States is known to have possessed three types of weapons of mass destruction: nuclear weapons, chemical weapons, and biological weapons. The U.S. is the only country to have used nuclear weapons in combat, when it detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki during World War II. It had secretly developed the earliest form of the atomic weapon during the 1940s under the title "Manhattan Project". The United States pioneered the development of both the nuclear fission and hydrogen bombs (the latter involving nuclear fusion). It was the world's first and only nuclear power for four years (1945–1949), until the Soviet Union managed to produce its own nuclear weapon. The United States has the second largest number of deployed nuclear weapons in the world, after Russia.
International concerns increased when Pakistani foreign secretary Shamshad Ahmad made a statement on 31 May warning that an escalation of the limited conflict could lead Pakistan to use "any weapon" in its arsenal. This was immediately interpreted as a threat of nuclear retaliation by Pakistan in the event of an extended war, and the belief was reinforced when the leader of Pakistan's senate noted, "The purpose
of developing weapons becomes meaningless if they are not used when they are needed". Many such ambiguous statements from officials of both countries were viewed as warnings of an impending nuclear crisis where the combatants would consider use of their limited nuclear arsenals in "tactical" nuclear warfare in the belief that it would not have ended in mutual assured destruction, as could have occurred in a nuclear conflict between the United States and the USSR. Some experts believe that following nuclear tests in 1998, the Pakistani military was emboldened by its nuclear deterrent to markedly increase coercion against India.
During the 1930s, innovations in physics made it apparent that it could be possible to develop nuclear weapons of incredible power using nuclear reactions. When World War II broke out, scientists and advisors among the Allies feared that Nazi Germany may have been trying to develop its own atomic weapons, and the United States and the United Kingdom pooled their efforts in what became known as the Manhattan Project to beat them to it. At the secret Los Alamos laboratory in New Mexico, scientist Robert Oppenheimer led a team of the world's top scientists to develop the first nuclear weapons, the first of which was tested at the Trinity site in July 1945. However, Germany had surrendered in May 1945, and it had been discovered that the German atomic bomb program had not been very close to success.The Allied team produced two nuclear weapons for use in the war, one powered by uranium-235 and the other by plutonium as fissionable material, named "Little Boy" and "Fat Man". These were dropped on the Japanese cities of Hiroshima and Nagasaki on August 6 and 9, 1945 each. This, in combination with the Soviet invasion of Japanese-controlled territory, convinced the Japanese government to surrender unconditionally. These two weapons remain the only two nuclear weapons ever used against other countries in war.
The deployment of ships carrying nuclear weapons caused complications during the Falklands War, and in the aftermath of that war it was decided to stockpile them ashore in peacetime. When the US withdrew its theatre nuclear weapons from Europe, the British government followed suit. The nuclear depth bombs were withdrawn from service in 1992, followed by the WE.177 free-fall bombs on 31 March 1998, and all were dismantled by the end of August.
The United States has refused to adopt a no-first-use policy, saying that it "reserves the right to use" nuclear weapons first in the case of conflict. The U.S. doctrine for the use of nuclear weapons was revised most recently in the Nuclear Posture Review, released April 6, 2010. The 2010 Nuclear Posture review reduces the role of U.S. nuclear weapons, stating that, "The fundamental role of U.S. nuclear weapons, which will continue as long as nuclear weapons exist, is to deter nuclear attack on the United States, our allies, and partners." The U.S. doctrine also includes the following assurance to other states: "The United States will not use or threaten to use nuclear weapons against non-nuclear weapons states that are party to the NPT and in compliance with their nuclear non-proliferation obligations."
A study published in the "Journal of Conflict Resolution" in 2009 quantitatively evaluated the nuclear peace hypothesis and found support for the existence of the stability-instability paradox. The study determined that while nuclear weapons promote strategic stability and prevent largescale wars, they simultaneously allow for more lower intensity conflicts. When a nuclear monopoly exists between two states, and one state has nuclear weapons and its opponent does not, there is a greater chance of war. In contrast, when there is mutual nuclear weapon ownership with both states possessing nuclear weapons, the odds of war drop precipitously.
The nuclear weapons debate refers to the controversies surrounding the threat, use and stockpiling of nuclear weapons. Even before the first nuclear weapons had been developed, scientists involved with the Manhattan Project were divided over the use of the weapon. The only time nuclear weapons have been used in warfare was during the final stages of World War II when United States Army Air Forces B-29 Superfortress bombers dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki in early August 1945. The role of the bombings in Japan's surrender and the U.S.'s ethical justification for them have been the subject of scholarly and popular debate for decades.
Nuclear disarmament refers both to the act of reducing or eliminating nuclear weapons and to the end state of a nuclear-free world. Proponents of disarmament typically condemn a priori the threat or use of nuclear weapons as immoral and argue that only total disarmament can eliminate the possibility of nuclear war. Critics of nuclear disarmament say that it would undermine deterrence and make conventional wars more likely, more destructive, or both. The debate becomes considerably complex when considering various scenarios for example, total vs partial or unilateral vs multilateral disarmament.
European nations had the potential to become Nuclear battlefields. If a war between superpowers were to break out, even if not originating in Europe, would quickly engulf it. The possibility of Warsaw pact nations under the USSR attacking Western Europe ensured all possible conflicts of nuclear escalation. It would escalate from conventional warfare to the use of tactical Nuclear weapons and then the possibility of going further and using intermediate nuclear weapons existed. The existence of nuclear weapons such as the U.S. Corporal missile, Redstone missile, Sergeant, and a missile called the Davy Crockett that was so small it could be fired by one man from the back of a jeep. These weapons given to Europe from the U.S. made it evident that if a nuclear war were to occur, it would almost surely engulf Europe as well. Strong ties, culturally, economic, and political tie the U.S with many European nations and the umbrella of NATO not only offered protection for these European countries, but also put them within the USSR's attack possibilities in a nuclear war.
The United States developed the first nuclear weapons during World War II in cooperation with the United Kingdom and Canada as part of the Manhattan Project, out of the fear that Nazi Germany would develop them first. It tested the first nuclear weapon on July 16, 1945 ("Trinity") at 5:30 am, and remains the only country to have used nuclear weapons in war, devastating the Japanese cities of Hiroshima and Nagasaki. It was the first nation to develop the hydrogen bomb, testing an experimental prototype in 1952 ("Ivy Mike") and a deployable weapon in 1954 ("Castle Bravo"). Throughout the Cold War it continued to modernize and enlarge its nuclear arsenal, but from 1992 on has been involved primarily in a program of Stockpile stewardship.[39][40][41][42] The U.S. nuclear arsenal contained 31,175 warheads at its Cold War height (in 1966).[43] During the Cold War, the United States built approximately 70,000 nuclear warheads, more than all other nuclear-weapon states combined.[44][45]