It was ‘MAD’. Mutually Assured Destruction – how the Cold War changed the world

Wilkie Collins, English playwright and author of ‘The Woman in White’, was writing about the concept of ‘Mutually Assured Destruction’ at least 75 years before the bombing of Hiroshima. In an 1870 letter he said the following:

“… I begin to believe in only one civilising influence – the discovery one of these days, of a destructive agent so terrible that War shall mean annihilation, and men’s fears shall force them to keep the peace.” (1)

Nuclear weapons are, alongside other weapons of mass destruction (WMDs), clearly the kind of destructive agent that Collins had in mind. However, rather than celebrating, I suspect that he would have been saddened by the 1960s US decision to use the threat of ‘mutually assured destruction’ in order to deter a nuclear first-strike attack by the Soviet Union.

John Foster Dulles, U.S. Secretary of State
United States government work

Unlike chemical and biological weapons, ‘nukes’ are of course a modern problem, only first used as a WMD in 1945. Yet just nine years later, John Foster Dulles (US Secretary of State) had made it clear that developing the capability for ‘massive retaliation’ with nuclear weapons was a nuclear deterrence policy goal of Eisenhower’s government:

“We need… more reliance on deterrent power… What the Eisenhower administration seeks is… a maximum deterrent at a bearable cost.

Local defenses must be reinforced by the further deterrent of massive retaliatory power… The way to deter aggression is for the free community to be willing and able to respond vigorously at places and with means of its own choosing.” (2)

The early 1960s hope was that ‘massive retaliation’ would mean that neither superpower would realistically believe that it could survive making a first-strike with nuclear weapons. In line with the ‘Nash equilibrium’ (4), the belief was that once each side has nuclear weapons and they know the equilibrium strategies of their opponent(s), neither side then has any motivation to either initiate a conflict or to disarm.

In 1962 Robert McNamara (US Secretary of Defence) was talking about a ‘no cities’ policy, whereby only military targets would be attacked in a second-strike response that would “… be so massive that the enemy would suffer assured destruction(3).

Robert McNamara – No known copyright restrictions

The problem was that despite extensive intelligence gathering operations, neither side could be sure of their enemy’s strategic goals, long-term plans or short-term intentions. The Cold War was being fought with incomplete and often inaccurate information, and hence neither side could be sure that an equilibrium had been achieved.

By 1964, as the Cold War intensified, McNamara had decided that the ‘no cities’ policy was an illusion, and that nuclear war could only be avoided by the threat of mutual destruction. William Lee, a US Defence Analyst, revealed that McNamara was convinced that “… the only way to have stable deterrence in the world was for both sides to be able to kill 25-50% of the other’s population.” (5)

B-52 bomber carrying 12 AGM-86B air-launched cruise missiles (ALCMs) on external pylons.
Public Domain

Under the MAD doctrine, each side had to have enough nuclear weapons that could survive their enemy’s initial attack and still be sufficient (at the least) to totally destroy them in retaliation. This led to the creation of diverse and dispersed ‘nuclear delivery systems’, including hardened, land-based silos, cruise missiles and ballistic missile submarines, all supposedly moderated by the 1972 Anti-Ballistic Missile Treaty (6).

MAD was a clear driver for the nuclear arms race.

Frighteningly, with MAD there was no middle ground, no opportunity to de-escalate a nuclear conflict – any use of nuclear weapons would immediately lead to assured destruction in the retaliatory attack.

McNamara said this about MAD: “… it’s not mad. Mutual Assured Destruction is the foundation of deterrence… if you want a stable nuclear world… it requires that each side be confident that it can deter the other…. if either side initiates the use of nuclear weapons, the other side will respond with sufficient power to inflict unacceptable damage.”

By 1961 the Soviet Union was at a disadvantage, with only 44 intercontinental ballistic missiles (ICBMs) and 155 heavy bombers, compared to the United States’ 156 ICBMs and 1,300 bombers. The US also had forward bases located in Europe, and two of its NATO allies (France and England) also had their own nuclear weapons. Following the Cuban missile crisis, by the mid-1960s the Soviets had increased their nuclear arsenal to around 400 missiles, including long-range SS-9s and small SS-11s (7).

Ensuring a credible second-strike capability required three different types of nuclear delivery systems, known as ‘the nuclear triad’: bombers, missiles and submarines. The triad meant that there was no possibility of an enemy’s first-strike attack destroying all of the other side’s nuclear forces. The triad became the foundation of nuclear deterrence in the Cold War, with fleets of ballistic missile submarines (‘SSBNs’) being guaranteed to complete a second-strike attack due to their stealthy nature and numbers. Interestingly, SSBNs’ guaranteed second-strike capability is so strong that today the UK’s nuclear deterrent is only projected through nuclear submarines carrying Trident II ballistic missiles (8).

USS Alabama (SSBN-731) – armed with 24 × Trident II D-5 ballistic missiles
By U.S. Navy photo by Ray Narimatsu – Public Domain (This image was released by the United States Navy with the ID 101029-N-1325N-005)

As part of their MAD strategy, the Soviet Union developed a ‘Dead Hand’ system (9). This system used seismic, light, radioactivity, and pressure sensors to detect a nuclear strike and then automatically command the launch of retaliatory second-strike weapons, even if the chain of command had otherwise been destroyed. It is believed that Russia still has this capability, although the system might usually be turned off.

The need for a second-strike capability means that, if the Nash equilibrium is to be maintained, nuclear forces have to be maintained in a continual state of alert, ready to fire whenever needed.

For example, beginning in the 1950s, the United States Strategic Air Command (SAC) kept one third of its bombers on alert, ready to take off within 15 minutes to attack targets in the Soviet Union.

When international tensions increased further in the 1960s, part of the bomber fleet was constantly in the air.

How dangerous is it to keep huge numbers of nuclear weapons on a hair trigger?

One misunderstanding… one error… one accident… boom!

The development of anti-ballistic missile systems (ABMs) by both the US and Soviet Union in the 1960s threatened to undermine the balance needed by the MAD doctrine.

Although they were a response to the Soviet’s A-35 ABM system around Moscow, the introduction of ‘Multiple Independently Targeted Re-entry Vehicles’ (MIRV) by the US further threatened the balance.

The US LGM- 118A Peacekeeper was one of the largest MIRVed missiles, holding up to 10 warheads with an individual yield of around 300 kilotons of TNT (a payload equal to about 230 Hiroshima-type bombs). This type of weapon was supposed to have been banned as part of the START II agreement, but unfortunately that has currently been abandoned by both superpowers (10).

The reality is that many civilian leaders and generals, in both the East and West, were not totally convinced about the balance presented by MAD.

Both sides continued to seek an advantage, installing ABM defences and making their weapons more effective even when reducing their numbers through treaties. One result was that a conventional war in Europe, or one involving the use of a small number of nuclear weapons (a ‘limited exchange’), was still likely to result in a full-scale nuclear war.

Reliance on MAD deteriorated when the Soviets invaded Afghanistan in the 1980s, showing that the doctrine could not resolve all threats to the United States’ interests (11)

In 1983, Ronald Reagan called for the introduction of missile defence saying: “To look down at an endless future with both of us sitting here with these horrible missiles aimed at each other and the only thing preventing a holocaust is just so long as no one pulls this trigger — this is unthinkable” (12). Regan sought to make nuclear war impossible, with both sides completely assured that neither could penetrate the other’s missile defences – in the face of that impossibility, nuclear disarmament becomes much more possible. However, his Strategic Defense Initiative (SDI) increased Soviet concerns about the West’s intentions and destabilised the MAD balance.

After all, if you had ICBMs and an effective missile shield, what would stop you from making a first-strike attack?

Although MAD might prevent either party from using nuclear weapons, it also presents a continuous threat to the life of every being on Earth in the process, through both the immediate effects of a massive retaliation and the nuclear winter that would follow.

Ironically, whilst MAD also means that neither side can realistically threaten to use their nuclear weapons, it does not deter a conventional attack.

To stop a Soviet attack on Western Europe, NATO would have had to respond with sub-nuclear forces. But sheer weight of numbers suggest that, unless NATO used WMDs, the Soviets had a strong likelihood of winning that war.

Today, both Russia and the United States continue to hold thousands of warheads in their nuclear arsenals. The conclusion must be that both sides continue to follow the MAD doctrine.


1 – “WILKIE COLLINS AND MUTUALLY ASSURED DESTRUCTION” – The Wilkie Collins Society newsletter, Spring 2009 –

2 – “John Foster Dulles on Massive Retaliation” – John Foster Dulles, “The Evolution of Foreign Policy,” Before the Council of Foreign Relations, New York, N.Y., Department of State, Press Release No. 81 (January 12, 1954) –

3 – “How did we forget about mutually assured destruction?” – Tom de Castella – BBC News Magazine –

4 – “Nash equilibrium” –

5 – “MAD” –  The Cold War TV series, episode 12 – Turner Broadcasting System and the BBC

6 – “The Anti-Ballistic Missile (ABM) Treaty at a Glance” – Arms Control Association –

7 – “Cold War” – Jeremy Isaacs & Taylor Downing (1998)

8 – “The UK’s nuclear deterrent: what you need to know” – UK Defence Nuclear Organisation and Ministry of Defence paper –

9 – “Dead Hand” –

10 – “START II and Its Extension Protocol at a Glance” – Arms Control Association –

11 – “How did the Soviet invasion of Afghanistan impact the Cold War?” –

12 – “Arms Race in the Era of Star Wars” – edited by David Carlton, Carlo Schaerf – Springer, for example

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