The Cold War: A MILITARY History (15 page)

People in the open are very vulnerable to INR, and the majority of radiation victims at Hiroshima and Nagasaki suffered from this initial radiation rather than from fallout. With high-yield nuclear weapons, however, the blast effect has a greater lethal range than INR, so that above a yield of about 100 kT INR ceases to be significant.

The ‘enhanced radiation warhead’ (popularly known as the ‘neutron bomb’) was designed to optimize the effects of INR, by using low-yield weapons in low airbursts over a target such as a company of tanks. The INR would have penetrated the armour and inflicted high radiation doses, while the low blast effect would have caused little serious damage to vehicles or buildings.

Residual Nuclear Radiation

Residual nuclear radiation is caused by materials which are vaporized in the initial heat and then sucked up as dust into the fireball, where they are irradiated and then fall back to earth as radioactive fallout. Larger particles return to earth within a few hours, but the remaining, increasingly small, particles may take weeks, or even months, to return to earth. The area covered lies downwind of ground zero and is generally elliptical in shape, giving rise to its colloquial name of the ‘fallout plume’.

Radiation is measured in
rads
, and accumulated doses have the following effects:
^fn6

Table 7.1
Examples of Lethal Effects of a Nuclear Explosion
²

Ionization of the Atmosphere

Nuclear explosions cause ionization of the atmosphere, which affects radio and radar systems whose waves pass through the disturbed areas. The period of disruption may be brief (a few seconds) or lengthy (several hours), and the severity will depend upon the yield of the nuclear explosion and its height, as well as upon the characteristics of the equipment itself. Systems which depend upon reflected waves, such as radars, tropospheric scatter systems and high-frequency radios, would be particularly affected.
^fn7

Electromagnetic Pulse (EMP)

EMP is an extremely powerful short-duration burst of broad-band radio energy generated by a nuclear explosion. This could affect electronic equipment, such as telephone systems, radio and television equipment, radars, computers and power supplies. As far as is known, it is harmless to man and animals.

EMP travels with the speed of light and radiates over 360 degrees and out to the line of sight from the source; thus, the higher the altitude of the burst the wider the area covered, until the point is reached where an exo-atmospheric burst would be intended primarily as an anti-electronic-systems weapon. An explosion at an altitude of 80 km would cover a circular area of 966 km radius, while an explosion at a height of 320 km would cover the whole of the contiguous United States and most of Canada.
^fn8
In a similar manner to lightning, EMP tends to home in on and then travel along conductors
such
as overhead or buried communications-cable runs, power cables, railway tracks and aircraft fuselages, and is particularly effective against transistorized equipment.

In aircraft, for example, EMP can cause computer malfunctions, inject energy into the aircraft wiring looms (resulting in unwanted signals to the equipment), and cause power surges which can result in system or component burn-out. This problem can be alleviated by shielding and filtering.

On the ground, protection against EMP is provided by careful planning of systems and good detailed design of equipments, including the use of efficient grounding (earth) and appropriate components. The EMP threat was taken very seriously in the West, particularly in the latter half of the Cold War, and vast sums of money were spent in developing and installing ‘nuclear hardening’ and in testing the results. Protection was also necessary against the EMP effects of weapons released by one’s own side; this might have included switching equipments off before an explosion.

Transient Radiation Effects on Electronics (TREE)

Although TREE occurs at the same time as EMP and has a similar source, it is a different phenomenon, caused by the initial nuclear radiation acting on electronic components. With high-yield nuclear weapons the range of TREE is probably less than that of damage caused by heat or blast, but it is of considerably greater significance in low-yield weapons, particularly those with enhanced-radiation warheads. Although the actual phenomenon is of very brief duration (typically a fraction of a second) the effect on electronic equipment may be long-lasting, if components are destroyed. Again, protection is achieved by good design and the use of filters.

NUCLEAR ATTACKS ON CENTRES OF POPULATION

A detailed assessment of the effects of nuclear weapons in a particular situation needs to take account of a wide variety of variable factors. In considering urban areas, for example, these include the location, density and distribution of the population in peacetime, as well as ambient conditions such as wind (which dictates the direction of the fallout plume), rain and temperature, all of which will affect the velocity and deceleration of the blast wave. The time of day is also relevant, not only because it will affect the ambient conditions, but also because the population distribution may be different between daytime and night-time, while the blinding effect of the light flash will be much more serious in the hours of darkness. Terrain also has an effect: for example, the blast wave will behave differently in hilly country compared to a plain.

Further differences arise according to whether the population has been
warned
of an impending attack, and, if so, whether it has been told to stay put (as in the UK), to disperse to the countryside (as in the USA) or to go to shelters (as in Sweden and Switzerland). The outcome will be further affected according to whether, having received the relevant instructions, the population has actually obeyed them. The availability of protective clothing – especially respirators – will also affect the outcome, as will the post-strike availability of the essentials of life such as food, water and fuel. House construction methods also have to be taken into account, since these vary not only between countries, but also between regions within a country and between areas in a city (for example, between poor and wealthy districts).

In interpreting nuclear-casualty tables, it is important to note that casualties and damage are not necessarily cumulative from the different causes. Thus, for example, people within the danger zone for radiation may well have already been killed by blast or fire, and they can only die once! Similarly, a communication link in the area susceptible to TREE or EMP might well not be functioning because its antenna mast has already been blown down by blast.

A PRE-EMPTIVE ATTACK ON MILITARY TARGETS

One of the concerns of both sides in the Cold War was of being subjected to a pre-emptive attack against their military forces. Most troop concentrations (such as barracks) either are in urban areas or form large population centres equivalent to urban areas. The effect of a nuclear strike on such troops would depend on whether they had received adequate warning of an attack, enabling them to disperse to rural areas and, once there, to take adequate protective measures.
^fn9
It would also depend on the distribution of the troops: in the former USSR, for example, troops deploying from an urban area likely to be a nuclear target would have been well advised to take up a position generally west of the city, since that would have placed them upwind of the fallout plume (the prevailing wind is westerly), although this might have placed them downwind of a strike on another city.

There were, however, yet more considerations for the military. It was possible that troops might have survived the attack only to discover that the city where their families had remained had been devastated. Depending upon the prevailing state of discipline, such troops might then have given priority to aiding the civil population rather than to taking part in any continuing military operations.

Airfields were somewhat different, since they covered large areas, while their population was concentrated in a small part of this. Most front-line airfields were essentially unprotected until the mid-1970s, when many of the facilities were given ‘nuclear hardening’ and fitted with filters.
^fn10
Such airfields would have been high-priority targets for the opposing side, although in some cases aircraft and their support facilities could be deployed away from the large static airfields; for example, the Swedish and German air force used highways as runways, while the British deployed their V/STOL (vertical/short take-off and landing) Harriers to greenfield sites.

Damage to ships from either an airburst or a groundburst would be primarily caused by the shock wave. A powerful weapon at close range could have caused the hull to rupture, or even made the ship roll over, while a more distant weapon might have damaged the superstructure and deck equipment without actually sinking the ship. From the 1970s onwards most new warships in the major navies were fitted with ‘NBC-proof citadels’ – proof against nuclear, biological and chemical weapons – giving the crew protection against immediate radiation and fallout, while wash-down systems provided effective decontamination.

As far as is known, no tests were conducted against submerged submarines. The usual method of destroying a submarine is by a depth charge, which is used to generate a large pressure near to the submarine with the aim of puncturing the pressure hull. A nuclear weapon would have served a similar, but very much more powerful, function, although its effect would have diminished with distance.

SECONDARY EFFECTS

Nuclear explosions give rise to consequential effects which are not a direct result of the explosion itself. For example, human casualties would have been far more likely to be caused by fires started by thermal radiation, or by flying debris (e.g. from falling buildings) and explosions (e.g. from ruptured gas mains), rather than by the blast effect itself. Similarly, in the post-strike period many deaths would have occurred from starvation and thirst (due to contamination or destruction of food stocks and water supplies), from exposure to cold climates (due to the destruction of buildings and clothing stocks), and from general debility and despair. There would also undoubtedly have been massive epidemics of diseases such as typhoid and cholera.

RURAL AREAS

Consideration of the effects of nuclear weapons usually concentrated on urban areas, where the human casualties would have been highest and the devastation most obvious. There would, however, have been many effects in the countryside. Even under non-nuclear conditions, grasslands, heath-lands, forests and some crops are extremely vulnerable to fire, especially during the dry season, and nuclear explosions would have been much worse. Indeed, since it was unlikely that human agencies would have been available to extinguish them, such fires could have raged over wide areas and for long periods. In addition, fallout would have affected both humans and animals in the rural areas, and, as in the urban areas, diseases would have spread rapidly.

Urban-population dispersal to the countryside, whether as government policy or as a panic measure, would inevitably have affected the rural areas and population. The sudden and unplanned arrival of large numbers of city-dwellers, ill-prepared both mentally and physically for rural life in a nuclear environment, would quickly have caused problems over accommodation, but in the mid-term the problems would have centred on food, water and disease.

LONG-TERM EFFECTS

A major unknown factor in assessing the long-term effects of nuclear war was that, apart from the very limited examples of Hiroshima and Nagasaki, there was no precedent for what would happen. There was a degree of agreement over the types of consequences of a nuclear strike, such as cancers and genetic abnormalities (certainly among women pregnant at the time of the nuclear war, and possibly also hereditary), but there was no agreement on the scale. The US Office of Technology Assessment, for example, estimated in 1980 that following a general nuclear war, long-term radiation might possibly affect between 3.5 and 25 million people in the USA, 16 to 44 million in the USSR, and 11 to 37 million in the rest of the world. The very wide ranges resulted from the extreme sensitivity of the estimates to the assumptions made – at one extreme, that all factors were favourable to the defence; at the other extreme, that all factors were unfavourable.

NUCLEAR TESTS

All known nuclear powers (the USA, the USSR, the UK, France and China) carried out long-running programmes of tests, while India conducted just
one
test. The majority of these tests were conducted in order to check that the devices would function properly, but many – particularly those conducted before the signing of the Partial Test Ban Treaty in 1963 – were also used to try to establish the effects of nuclear explosions on buildings, aircraft, ships and so on.