The Soviet Union was not officially informed of the American experiments until Stalin was informed at the Potsdam Conference on July 24,1945. The Americans did not trust the Soviets to keep the information from German spies; there was also deep distrust of the Soviets and their intentions, despite the wartime partnership. Even during the war many government and military figures in the USA saw the USSR as a potential enemy in the future.
Despite this, the Soviets were well aware of the program due to a spy ring operating within the American nuclear program. The atomic spies (including Klaus Fuchs and Theodore Hall) kept Stalin well informed of American developments . When U.S. President Harry S. Truman informed Stalin of the weapons, he was surprised at how calmly Stalin took the news and thought that Stalin had not understood what he had told him. In fact Stalin had long been aware of the program. The American program had been so secret that even Truman did not know about the weapons until he became president; Stalin had thus known about the Manhattan Project before Truman himself did.
In August of 1945, atomic bombs were dropped per Truman's order on designated Japanese cities. The first bomb was dropped on Hiroshima, and then another bomb was dropped on Nagasaki by the B-29 bombers Enola Gay and Bock's Car respectively.
Governments devoted massive amounts of resources to increasing the quality and quantity of their nuclear arsenal. Both nations quickly began work on hydrogen bombs and the United States detonated the first such device on November 1, 1952. Again the Soviets surprised the Americans by exploding a deployable thermonuclear device of their own the next August, though it was not actually a "true" multi-stage hydrogen bomb (that would wait until 1955). The Soviet H-bomb was almost completely a product of domestic research, as their espionage sources in the USA had only worked on very preliminary (and incorrect) versions of the hydrogen bomb.
The most important development in terms of delivery in the 1950s was the introduction of ICBMs. Missiles had long been seen as the ideal platform for nuclear weapons and in 1957 on the 4th of October with the launch of Sputnik the Soviet Union showed the world that they had missiles that could hit anywhere in the world. The United States launched their own on the 31 October 1959. The Space Race showcased technology that was critical to nuclear weapons delivery (the ICBM boosters) while maintaining the benign aegis of science and exploration.
This period also saw attempts begin to defend against nuclear weapons. Both powers built large radar arrays to detect incoming bombers and missiles. Fighters to use against bombers and anti-ballistic missiles to use against ICBMs were also developed. Large underground bunkers were constructed to save the leadership of the superpowers, and individuals were told to build fallout shelters and taught how to react to a nuclear attack (civil defense). These bombs could kill millions in the event of an attack by either side.
Both Soviet and American thinkers hoped to use nuclear weapons to extract concessions from the other side, or from other powers such as China, but the risk of any use of these weapons was so large that both sides refrained from what John Foster Dulles referred to as brinkmanship. While some like General Douglas MacArthur argued nuclear weapons should be used during the Korean War both Truman and Eisenhower disagreed.
Both sides were also unaware of how their relative arsenals compared. The Americans tended to be lacking in confidence, in the 1950s they believed in a non-existent "bomber gap" (aerial photography later discovered that the Soviets had been playing a sort of Potemkin village game with their bombers in their military parades, flying them in large circles to make it appear they had far more than they truly did), and the 1960 American presidential election saw accusations of a wholly spurious "missile gap" between the Soviets and the Americans. The Soviet government structure tended to exaggerate the power of Soviet weapons to the leadership and Nikita Khrushchev.
An additional controversy formed in the United States during the early-1960s over whether or not it was known if their weapons would work at all if it came down to it. All of the individual components of nuclear missiles had been tested separately (warheads, navigation systems, rockets), but it had been infeasible to test them all as a whole. Critics charged that it was not really known how a warhead would function in the gravity forces and temperature differences encountered in the upper atmosphere and outer space, and Kennedy was unwilling to run a risky test of an ICBM with a live warhead. The closest thing to an actual test, Operation Frigate Bird, which involved testing a live submarine launching a ballistic missile, was challenged by critics (including Curtis LeMay, who used doubt over missile accuracy to encourage the development of new bombers) on the grounds that it was a single test (and could therefore be an anomaly), was a lower-altitude SLBM (and therefore was subject to different conditions than an ICBM), and that significant modifications had been made to its warhead before testing.
|Source: Gerards Segal, The Simon & Schuster Guide to the World Today, (Simon & Schuster, 1987), p.82 in: Edwin Bacon, Mark Sandle, "Brezhnev Reconsidered", Studies in Russian and East European History and Society (Palgrave Macmillan, 2003)|
In addition to the United States and the Soviet Union, three other nations, the United Kingdom, People's Republic of China, and France also developed far smaller nuclear stockpiles. In 1952, the United Kingdom became the third nation to possess nuclear weapons when it detonated an atomic bomb in Operation Hurricane in Australia on October 3, 1952. During the Cold War, British nuclear deterrence came from submarines and nuclear-armed aircraft. The Resolution class ballistic missile submarines armed with the American-built Polaris missile provided the sea deterrent, while aircraft such as the Avro Vulcan, SEPECAT Jaguar, Panavia Tornado and several other Royal Air Force strike aircraft carrying WE.177 gravity bomb provided the air deterrent.
France became the fourth nation to possess nuclear weapons on February 13, 1960, when the atomic bomb Gerboise Bleue was detonated in Algeria, then still a French colony. During the Cold War, the French nuclear deterrent was centered around the Force de frappe, a nuclear triad consisting of Dassault Mirage IV bombers carrying such nuclear weapons as the AN-22 gravity bomb and the ASMP stand-off attack missile, Pluton and Hades ballistic missiles, and the Redoutable class submarine armed with strategic nuclear missiles.
The People's Republic of China became the fifth nuclear power on October 16, 1964, when it detonated a uranium-235 bomb in a test codenamed 596. Due to Soviet/Chinese tensions, the Chinese might have used nuclear weapons against either the United States or the Soviet Union in the event of a nuclear war between the United States and the Soviet Union. During the Cold War, the Chinese nuclear deterrent consisted of gravity bombs carried aboard H-6 bomber aircraft, missile systems such as the DF-2, DF-3, and DF-4, and in the later stages of the Cold War, the Type 092 ballistic missile submarine.
These treaties were only partially successful. Both states continued building massive numbers of nuclear weapons, and new technologies such as multiple independently targetable reentry vehicles (also known as MIRVs) limited the effectiveness of the treaties. Both superpowers retained the ability to destroy each other many times over.
After the Cold War ended, a large amount of resources and money which was once spent on developing nuclear weapons in USSR was then spent on repairing the environmental damage produced by the nuclear arms race, and almost all former production sites are now major cleanup sites. In the USA, the plutonium production facility at Hanford, Washington and the plutonium pit fabrication facility at Rocky Flats, Colorado are among the most polluted sites.
United States policy and strategy regarding nuclear proliferation was outlined in 1995 in the document "Essentials of Post-Cold War Deterrence".
Despite efforts made in cleaning up uranium sites, significant problems stemming from the legacy of uranium development still exist today on the Navajo Nation in the states of Utah, Colorado, New Mexico, and Arizona. Hundreds of abandoned mines have not been cleaned up and present environmental and health risks in many Navajo communities. In addition to this, Navajo communities now have to face proposed new uranium solution mining that threatens the only source of drinking water for 10,000 to 15,000 people living in the Eastern Navajo Agency in northwestern New Mexico. The Southwest Research and Information Center (SRIC) aims to provide the public with information on resource exploitation on the people and their cultures, lands, water, and air of the American Southwest.