The Arms Race (AQA GCSE History) : Revision Note
Why did an Arms Race occur after 1945? - Timeline & Summary
The USA dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki in August 1945. This marked the start of what historians call 'The Arms Race'. This was a period of time when the USA and the Soviet Union competed against each other to create and stockpile the most advanced weapons.
World leaders believed that nuclear technology would prevent either country from becoming too powerful. From 1950-58, nuclear technology vastly developed with the creation of hydrogen bombs and Inter-Continental Ballistic Missiles (ICBMs). The Arms Race later developed into an ambition for space supremacy in the Space Race of the 1960s.
The Arms Race intensified Cold War tensions between the USA and the Soviet Union. By 1958, both sides possessed and perfected weaponry that could destroy the world. This increased the mutual distrust between the two countries. The Cuban Missile Crisis showed how distrust over nuclear weapons can cause conflict. New weaponry was considered a way to ensure peace. Many countries still possess nuclear weapons today as they believe they are a deterrent to large-scale war.
The Arms Race in the Cold War
Truman authorised the use of atomic bombs to end the war with Japan in August 1945
At the time, the USA and the Soviet Union were allies under the Grand Alliance
Their relationship had worsened after the defeat of Nazi Germany in May 1945 and the subsequent peace conferences
Historians believe that the USA's intentions behind the bombings of Hiroshima and Nagasaki were as a warning to Stalin
At the Potsdam Conference, Truman informed Stalin that the USA had developed:
"a new weapon of unusual destructive force"
The bombings of Hiroshima and Nagasaki showed that the USA was the strongest superpower
This aimed to stop the Soviet Union's growing international dominance
After the bombings, Stalin instructed Soviet scientists to begin developing their own atomic bomb
He did not want the USA to retain a nuclear monopoly for too much longer
Stalin understood that, to defend against US aggression, the Soviet Union needed the same weaponry that the USA had
By 1949, the Soviet Union successfully developed their first atomic bomb
The USA felt the need to develop more powerful technology to defend against the growing threat of the Soviet Union
This marked the beginning of the Arms Race between the USA and the Soviet Union
The USA and the hydrogen bomb
Some of the US scientists behind the Manhattan Project created the hydrogen bomb
Edward Teller developed the idea of the hydrogen bomb during the Manhattan Project
After the Second World War, Teller petitioned the US government on multiple occasions to give him funding to research and create the hydrogen bomb. The government denied each of his requests
The uncovering of a spy within the USA's nuclear team triggered the development of the hydrogen bomb
Klaus Fuchs was a scientist who had worked on the Manhattan Project
In 1950, the US government had evidence of Fuchs' espionage. From 1942 onwards, he passed on information about American nuclear technology to the Soviet Union
The US government argued that Fuchs' information sped up the Soviet Union's creation of the atomic bomb by one year
Truman gave permission to Teller to begin the creation of the hydrogen bomb
Teller and his colleague Stanislaw Ulam created the first hydrogen bomb in 1952
'Ivy Mike' was the first hydrogen bomb tested
In 1953, Russia developed the technology to create a hydrogen bomb
How was the hydrogen bomb different to the atomic bomb?
A hydrogen bomb is much more powerful than an atomic bomb
| Atomic bomb | Hydrogen bomb |
|---|---|---|
Detonation | Nuclear fission. The bomb explodes when radioactive atoms like uranium break apart | Nuclear fusion. The bomb explodes when two radioactive atoms come together to form a third atom |
Power | Approximately 1,000 kilotons | Approximately 10,000 kilotons |
Destructive ability | The atomic bombs in Hiroshima and Nagasaki killed 20,000 people instantly. They had a blast radius of roughly 5 square miles | In tests, hydrogen bombs had a blast radius of roughly 44 square miles. The radiation of the bomb could reach up to 18 miles away from detonation |
A hydrogen bomb is 1,000 times more powerful than an atomic bomb
This shows how quickly nuclear technology developed in the 1950s
By the 1960s, the hydrogen bomb had become an incredibly dangerous weapon
The Soviet Union tested 'Tsar Bomba' in 1961. It was the largest man-made explosion recorded in history, at 50,000 kilotons (or 50 megatons)
The original version of Tsar Bomba was twice as powerful as the one tested in 1961
Soviet scientists believed that it was too dangerous to test
Mutually Assured Destruction & Brinkmanship
By the 1960s, the USA and the Soviet Union had increasingly devastating nuclear technology
The creation of Inter-Continental Ballistic Missiles meant that either country could launch a nuclear strike across the world in minutes, with little warning
Polaris missiles could be launched from submarines hidden underwater, making a surprise counterattack even more likely
As a result, two key ideas developed:
Mutually Assured Destruction (MAD)
Brinkmanship
What is Mutually Assured Destruction (MAD)?
MAD was the idea that if either the USA or USSR launched a nuclear attack, the other side would respond with a full attack too
This would lead to the annihilation of both countries and possibly the world
How did MAD keep peace?
As both sides had enough weapons to destroy each other completely, neither dared to start a war
The fear of total destruction made leaders more cautious, especially during crises
What is Brinkmanship?
Brinkmanship was a strategy of pushing a situation to the edge of war without actually starting one
It was meant to scare the other side into backing down
The idea was for a country to appear strong and prepared to use force, even if they were not planning to
Examples of Brinkmanship and MAD in the Cold War
The Berlin Blockade (1948–49)
The USSR tried to force the West out of Berlin by cutting off supplies
The USA responded with the Berlin Airlift
The USA were not force out of Berlin but avoided an open conflict
The Cuban Missile Crisis (1962)
For 13 tense days, the world was on the brink of nuclear war
Eventually, both sides used diplomacy to solve the crisis
This showed how MAD influenced decisions and helped avoid war
Examiner Tips and Tricks
Many students mix up Mutually Assured Destruction (MAD) and Brinkmanship.
Think of MAD as a form of nuclear 'balance'. Both sides are holding weapons, but no one dares to use them.
Brinkmanship is about nuclear 'instability'. A superpower would deliberately push a crisis to the brink of war to force the other side to back down.
The impact of the Arms Race
Fear of nuclear war and civil defence
Governments began making preparations for a possible nuclear war, especially in the USA
‘Duck and Cover’
In the 1950s, the US government launched the “Duck and Cover” campaign
Schoolchildren were taught to hide under their desks and cover their heads in the event of a nuclear explosion
Leaflets, films, and posters gave advice on how to survive a nuclear attack — although in reality, survival chances were low
Fallout shelters
Families were encouraged to build nuclear shelters in their gardens or basements
Some people stockpiled food, water, and supplies in case of a nuclear strike
These actions show how the arms race created constant anxiety and shaped people's behaviour
Opposition and protest movements
In Britain, the Campaign for Nuclear Disarmament (CND) was founded in 1958
It became one of the largest protest movements in Britain
Its symbol became widely recognised around the world
The CND organised marches, protests, and public campaigns demanding that the UK and other countries give up their nuclear weapons
The Arms Race and popular culture
The fear of nuclear war and the arms race also had a big impact on culture during the Cold War
The film Dr Strangelove was a dark comedy that criticised the arms race and the idea of Mutually Assured Destruction
It showed how nuclear war could happen by accident or human error, and mocked the idea that either side could control such a conflict
Films like The Day the Earth Stood Still (1951) and Threads (1984) explored nuclear themes and the end of the world
Worked Example
How useful are Sources B and C to a historian studying attitudes towards nuclear weapons during the Cold War?
[12 marks]
Source B: Extract from a speech by US Secretary of Defence Robert McNamara, 1967
“No sane citizen, political leader or nation wants thermonuclear war… Assured destruction is the very essence of the whole deterrence concept… We must possess an actual assured-destruction capability, and that capability also must be credible.”
Source C: Film poster for Dr Strangelove (1964)
Answer:
Source B is useful to a historian because it shows the official attitude of the US government towards nuclear weapons in the 1960s. McNamara explains the policy of Mutually Assured Destruction (MAD), where both the USA and USSR had enough nuclear weapons to destroy each other. He says that to stop war, a country must have a “credible” threat of destruction. This reflects how US leaders believed that nuclear weapons were necessary to prevent war, rather than to fight one. The source is from a speech by the US Secretary of Defence. Therefore, this source is very useful to a historian because it shows how Cold War leaders used the threat of destruction as a way to maintain peace.
Source C is also useful to a historian because it shows public and cultural reactions to nuclear weapons. The film Dr Strangelove is a dark comedy that mocks the idea of nuclear war and criticises how world leaders handled the threat. The title “How I Learned to Stop Worrying and Love the Bomb” suggests a growing public fear and frustration, as well as the feeling that governments were not handling the threat responsibly. As a film poster, the source helps historians understand the fear that the public had about nuclear warfare and how everyday people used humour to cope with this fear.
Together, these sources are useful because they show two different attitudes towards nuclear weapons during the Cold War: one from a government official, and the other from popular culture. Source B explains the logic behind nuclear deterrence, while Source C shows how people could react to fear with comedy. Together, they help a historian understand how nuclear weapons shaped both political decisions and public opinion during the Cold War.
Examiner Tips and Tricks
To achieve high marks for this question, you should:
refer to the content and provenance of the sources
include knowledge that is relevant to the source
make a judgement on how useful the source is for the given issue in the question
For further guidance on this question, you can read this revision note on how to answer the 12-mark"How useful" question.
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