Nuclear weapons

nuclear weapons

The devastating blast of a nuclear weapon

Cold War tensions and paranoia were largely driven by the fear of nuclear war. The United States was the first nation to construct and test nuclear weapons – and, following the bombing of Hiroshima and Nagasaki, it remains the only nation to have used them in wartime. America’s nuclear weapons program, the Manhattan Project, began in 1942 and proceeded under the guidance of Dr Robert Oppenheimer. The first American nuclear device, the ‘Gadget’, was test-fired in mid-July 1945. These devices created energy and destructive power that was unparalleled in human history. Even a small nuclear weapon, like the 18-21 kiloton devices detonated over Japan, had the capacity to utterly destroy a major city. These terrifying weapons produced flash-blindness, devastating blast waves and temperatures up to 10,000 degrees Celsius. For those who survived the initial blast, there was also the threat of lingering radioactivity, fallout (radioactive particles dispersed by the weather) and radiation sickness.

Moscow gets the bomb

nuclear weapons

The blast from ‘Joe-1’, the first Soviet nuclear weapons test, fired in Kazakhstan in 1949

The USSR had its own nuclear program almost three years before the bombing of Hiroshima. Soviet agents in America learned of the Manhattan Project as early as 1941. This information was passed to Moscow, which initiated research into nuclear weapons the following year. In 1945 Soviet spies obtained information of immense importance: American diagnostic plans and blueprints for a nuclear weapon. These plans allowed the fast-tracking of Soviet nuclear weapons technology. In August 1949, the Russians detonated their first prototype nuclear weapon. Code-named ‘First Lightning’ by the Russians and ‘Joe 1’ by the Americans, it was similar in design, appearance and yield to the ‘Fat Man’ bomb that had decimated Hiroshima.

Within six years Soviet nuclear physicists had test-fired several nuclear weapons, each more elaborate and powerful than their predecessors. In 1955 they air-dropped a hydrogen bomb with a yield of 1.6 megatons, capable of utterly destroying a city of one million people. Both the US and the USSR also had sizeable missile programs, which used parallel technology to their research into space exploration. By the late 1950s both countries had developed intercontinental ballistic missiles (ICBMs), a frightening new technology that allowed the long-range delivery and detonation of nuclear warheads. ICBMs were more cost-effective than aircraft, and unlike bombers they were almost impossible to intercept. They were also much faster: an ICBM could be launched into sub-orbital flight from a missile silo before hitting targets halfway around the globe in less than 45 minutes. Shorter range missiles could be launched from battleships and submarines, further reducing response times.

The nuclear arms race

“But what about the Russians? Every time the Pentagon needs more money, the Russian spectre is called up. The reality is that if both superpowers, together with the lesser powers, continue on this mad spiraling arms race, building more and more atomic weapons, sooner or later they will be used. We cannot trust in the sanity and stability of world leaders. Someone must make the first move away from death and toward life… I believe the Russian people are so frightened of nuclear war that they would heave a momentous sigh of relief and would want their own leaders to follow America’s moral initiative toward disarmament.”
Helen Caldicott
Anti-nuclear activist
nuclear weapons

A table showing the comparative nuclear arsenals of the US and USSR

The Soviet atomic tests of the early 1950s heralded the beginning of a nuclear arms race – the most frightening aspect of the Cold War. Both powers invested heavily in their nuclear weapons programs, partly because neither ever had an accurate idea of the nuclear arsenal of the other. The US, believing in non-existent shortfalls between its own arsenal and that of the USSR (the so-called ‘bomber gap’ and ‘missile gap’) focused on stockpiling large amounts of nuclear devices. By 1962 America had almost 7,000 nuclear warheads, in comparison to Soviet Russia’s 500 warheads. American nuclear weapons production eased during the mid-1960s; by 1970 the US had just under 4,000 nuclear warheads, almost half the amount from a decade before. Instead of increasing their nuclear stockpile, US military planners turned their attention to new and more efficient ways of delivering nuclear and non-nuclear weapons.

nuclear weapons

A diagram showing the comparative size of ‘Tsar Bomba’. Graphic: Rindo Ramankutty.

The Soviets, in contrast, continued to increase nuclear weapons production through the late 1960s and 1970s. Moscow opted for size rather than quantity, ordering a much greater number of strategic weapons (high-yield nuclear warheads for use against enemy cities or installations) than tactical devices (small nuclear-tipped weapons for battlefield use). In 1962 the Russians test-detonated Tsar Bomba (‘king of bombs’) – a hydrogen bomb eight metres in length and weighing 27 tons – on an island in remote northern Siberia. With an explosive yield the equivalent of 50 megatons, Tsar Bomba was 1,400 times larger than the ‘Fat Man’ device that devastated Hiroshima, and ten times the strength of all the explosives fired by all countries during World War II. In the mid-1970s, the total megatonnage of Soviet nuclear weapons passed that of the US – though the Americans had double the number of individual nuclear devices. The US and USSR were not the only countries to develop and manufacture nuclear weapons. Other entrants to the ‘nuclear club’ during the Cold War included Britain (1952) France (1960) China (1964) India (1974) Israel (late 1970s) and South Africa (early 1980s). Several NATO nations (Belgium, Canada, Germany, Greece, Italy, the Netherlands and Turkey) also had control of ‘shared’ US nuclear weapons, to be used in the event of war with the Soviet bloc. Some countries, such as Australia and Japan, possessed the technology to construct nuclear weapons but opted against this.

Mutually-assured destruction

nuclear weapons

An artist’s impression of nuclear winter, a permanent state of darkness caused by nuclear war

The proliferation of nuclear weapons produced a strategic doctrine called ‘mutually-assured destruction’, aptly given the acronym MAD. This strategy was based on the knowledge that the nuclear firepower of both the US and USSR was capable of utterly destroying the other – and that if one nation launched a nuclear attack, the other would detect it and reciprocate with a nuclear strike of similar force. MAD proponents argued that since launching a nuclear attack was akin to signing your own country’s death warrant, this served as a deterrent to nuclear aggression. Hindsight suggests that MAD was ultimately effective (there was never a nuclear exchange between the US and the USSR) but it was an extremely risky policy. MAD was most fragile at moments of high tension, such as the 1962 Cuban missile crisis, when the US government was hours away from ordering a bombing run against Soviet missile positions and troops based in nearby Cuba. After the Cold War it was revealed that in the event of a war with the USSR, American and British military commanders had authorisation to use tactical nuclear weapons (smaller warheads, for use on the battlefield); in contrast, Soviet orders determined that any nuclear attack on its forces legitimised a full-scale nuclear response.

nuclear weapons

American children were taught responses to nuclear strikes, such as jumping under desks

The threat of nuclear war between America and the Soviet Union underpinned the tensions and paranoia of the Cold War. It coloured political rhetoric (in 1956 Soviet leader Nikita Khrushchev famously told European ambassadors that “We will bury you!”) and Cold War propaganda. It also shaped domestic policies and permeated popular culture. Local governments in both countries developed and advertised precautions and responses for a nuclear strike, such as air-raid sirens, public shelters and emergency procedures. American civilians and schoolchildren were taught to ‘duck and cover’ in the event of a nuclear flash. Some private citizens installed underground air-raid shelters in their homes, complete with food stockpiles and equipment to ‘sit out’ long periods if radioactive fall-out made the ground uninhabitable. The likelihood of nuclear warfare spawned protest movements and ‘doomsday cults’; fears were expressed in art, poetry and song, from Barry McGuire’s 1965 Eve of Destruction to Sting’s 1985 Russians.



1. Developed and utilised towards the end of World War II, nuclear weapons had enormous destructive capacity.
2. Soviet spies infiltrated the US nucear program, which allowed the USSR to test its first nuclear weapon in 1949.
3. Nuclear weapons were enhanced by new intercontinental missile systems that could carry them vast distances.
4. The 1950s saw the beginning of a nuclear arms race and the doctrine of ‘mutually-assured destruction’.
5. Concern and paranoia about nuclear weapons permeated Cold War society, particularly in the West, where civil defence programs prepared civilians for possible nuclear attack.

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This page was written by Jennifer Llewellyn, Jim Southey and Steve Thompson. To reference this page, use the following citation:
J. Llewellyn et al, “Nuclear weapons”, Alpha History, accessed [today’s date],