How have nuclear weapons shaped global politics? 10 key moments in the post-war atomic world

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The USA believed it had reasserted its nuclear primacy when it tested the first hydrogen bomb, destroying the Pacific island of Elugelab. The bomb employed a nuclear explosion that heated hydrogen isotopes sufficiently to fuse them into helium atoms, a transformation that released far more destructive energy than the atom bomb. US superiority, however, was short-lived: Britain became the third atomic power in 1952, while the Soviet Union developed its own H-bomb in 1953.

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Successful spying on Western nuclear technology enabled the Soviet Union to complete its development of an effective nuclear bomb. At a stroke, the USA’s nuclear monopoly, which appeared to offer the Americans a means to coerce the Soviets, came to an end. This development had required a formidable effort, as the Soviet Union was devastated by the impact of the Second World War. It was pursued because Stalin believed that only nuclear parity would permit the Soviet Union to protect and advance its interests. However, the policy was seriously harmful to the economy, as it led to a distortion of research and investment choices. It was also militarily questionable, as the Soviets used resources that might otherwise have developed their conventional capability.

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The launch by the Soviet Union of the first satellite to go into orbit revealed a capability for intercontinental rockets that brought the entire world within striking range, and thus made the USA vulnerable to attack. In strategic terms, rockets threatened to realise the doctrine, so often advanced in the 1920s and 1930s, that air power is a war-winning tool; at the same time, they rendered the nuclear capability of the slower bombers of the American Strategic Air Command obsolete. This new capability made investment in expensive rocket technology seem essential, altering the character of both anti-nuclear defence and nuclear deterrence. In the USA, President Eisenhower was alerted to the increased threat to national security by a secret report from the Gaither Committee.

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Submarines could be based near the coast of target states, and were highly mobile and hard to detect. As a result, the firing of a ballistic missile by the American submarine, USS George Washington, off Cape Canaveral, Florida, represented a shift in force structure, away from the air force and towards the navy. The navy argued that its submarines could launch carefully-controlled strikes, permitting more sophisticated deterrence and retaliation management. Other states followed. Also in 1960, France became the fourth power to possess an atom bomb.

This was the first major step to remove the threat of nuclear war in Europe. Cold War tensions had increased throughout the early 1980s, as fears of Soviet aggression led NATO to deploy tactical nuclear weapons, carried on Cruise and Pershing intermediate-range missiles. The treaty banned land-based missiles with ranges between 500 and 5,000 kilometres, and also set up a system of verification through on-site inspection. Mikhail Gorbachev, the Soviet leader, was willing to challenge the confrontational world view outlined in KGB reports. He was convinced that American policy on arms control was not motivated by a hidden agenda of weakening the Soviet Union, and this encouraged him to negotiate with the West.

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The world came close to nuclear war as the Soviet Union deployed missiles in Cuba, a Communist state being threatened by the USA. With Washington in range of these missiles, the USA imposed an air and naval quarantine to prevent the shipping of further Soviet supplies. It also considered an attack on Cuba, and threatened a full retaliatory nuclear strike if the Soviet missiles were fired. The prospect of nuclear war may have helped prevent conventional military operations, which would have begun with a US air attack on the Soviet bases on Cuba. In the eventual agreement, the Soviet Union agreed to remove the missiles; in return, the USA withdrew their Jupiter missiles from their ally Turkey, and agreed not to invade Cuba. During the Berlin Crisis of the previous year, President Kennedy had reaffirmed the willingness to use atomic weaponry even if the Soviets did not, as West Berlin was particularly vulnerable to Soviet conventional attack.

Equipped with multiple independently targeted re-entry vehicles (MIRVs), which had first been tested in 1968, these missiles benefited from a greatly enhanced strike capacity. As a consequence, warhead numbers, and thus the potential destructiveness of a nuclear exchange, rose greatly. This was part of the race to enhance nuclear capability, which also saw the Americans cutting the response time of their land-based intercontinental missiles by developing the Titan II missile. The Titan had storable liquid propellants, which enabled in-silo launches and therefore improved the reaction time of the missiles in the event of a nuclear conflict.

SALT I, a treaty between the USA and the Soviet Union, was a major attempt to diminish the possibility of nuclear war. The treaty limited the construction of defensive shields against missile attack to two anti-ballistic missile complexes, one around a concentration of intercontinental ballistic missiles and the other around the capital.

By leaving both powers vulnerable, SALT I was designed to discourage a first strike, on the basis that there would be no effective defence against a counter strike. Thus, atomic weaponry was to be used to prevent, not to further, nuclear war. The treaty, which limited the two powers’ nuclear arsenal, also served as the basis for further negotiations which led to the SALT II treaty in 1979.

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The nuclear strength of these powers became more of a problem as Cold War tensions ebbed and as they developed their missile forces. India had possessed atomic weapons from 1974 and Pakistan from 1988, but they displayed their weaponry more openly as national rivalry grew in the wake of clashes over Kashmir in the late 1990s and early 2000s. Both nations publicly tested nuclear weapons in 1998. That year, Pakistan test-fired its new Ghauri intermediate-range missile, while, in 1999, India fired its new long-range Agni 2 missile: its range extended to Tehran and most of China and South-East Asia. Both countrys’ short-range, surface-to-surface missiles, tested in 2003, were able to carry nuclear warheads.

Jeremy Black is the author of Using History (Hodder Arnold, 2005)

This article was first published in the August 2005 issue of BBC History Magazine