MODERNIZATION OF NUCLEAR WEAPONS

The modernization of nuclear weapons actually makes their use in war more likely. Take miniaturization. Whereas the bomb dropped on Hiroshima weighed 4000 kilogrammes, the US has already deployed Atomic Demolition Mines with the same explosive power as the Hiroshima bomb but weighing only 180 kilogrammes - a ground team of six soldiers can put it in position. And it is now developing a lightweight nuclear mine (called ADAM, or Advanced Atomic Mine) small enough to be carried in a soldier's rucksack This makes nuclear war highly manoeuvrable - and containable within a 'neutral' battleground such as Western Europe or the Pacific,

On the other hand, the modernization of missiles such as the American MX and Cruise and the Soviet SS-20 means that fewer launchers are needed to reach more targets. Each of these have multiple warheads and are much more accurate than the missiles they replaced.

The new generation of missiles, which are MIRVs or multiple independently targeted re-entry vehicles', can be launched from land or sea, cross an ocean and a continent and still hit their target to within 100 metres. This new accuracy means that for the first time military planners can be confident of hitting hard targets such as missile silos - thus making possible a first strike which would destroy the other side's missiles before they could be launched. The development of space-based or anti-satellite weapons is now well under way, too.

These scientific developments make nuclear weapons part of a range of available military options instead of just the ultimate threat. They encourage politicians and the military in the notion that nuclear war can be controlled - as well as adding ever more twists to the arms spending spiral.

STAR WARS

The official name for what has come to be known as Star Wars is the Strategic Defense Initiative (SDI). This is based on President Reagan's vision of an impenetrable shield which would keep out enemy missiles. He pictured Soviet missiles being detected by surveillance satellites, targeted by a space-based weapons system and then exploded as they emerged through the atmosphere. The ideal would be to destroy the missile while it was still over the Soviet Union by means of laser beams or kinetic energy weapons. But back-up 'layers of defence' would try to catch the missiles in space or on re-entry into the earth's atmosphere.

Most independent analysts agree that it would be impossible to make such a protective shield foolproof - the other side would always find a new way through. Indeed the US doubled its funding in 1986 for the Advanced Strategic Missile Systems programme, designed to do just this - to find a way through a Russian 'shield' should they develop one. Even the original proposal does not provide for defence against low-flying bombers or Cruise missiles, which hug the contours of the earth.

The SDI programme has also contributed a new upswing to the arms race - its most enthusiastic advocates are the businesspeople in the defence industry ('it is the business opportunity of a generation. the scramble for that pot of gold is on', commented the Wall Street Journal). It is astronomically expensive even by military standards - recent estimates point to an overall cost of $1,000 billion.

But if the US believed that it was protected by a shield from the effects of nuclear war, it might be more likely to use its own missiles - especially if it knew that its protection from the other side's ingenuity was only temporary

NUCLEAR WINTER

Nuclear explosions produce enormous amounts of sooty smoke, and a major nuclear exchange - even if it was tactically limited to Western Europe - would produce a huge dark cloud covering not just the combat zone but also much larger areas of the globe. Scientists have calculated that a war involving the use of half the world's nuclear weapons would leave 40 million tonnes of fine soil dust and pulverized rock in the upper atmosphere, This smoke cloud would then absorb the sunshine so that little reached the ground below. The resulting cooling and darkness has been called the nuclear winter.

The extent of the damage this caused would depend on the scale of the initial conflagration but our global food system is very vulnerable even to small changes in seasonal mean temperature and rainfall. A temperature drop of just two degrees centigrade in the growing season would reduce total grain production by around half. And if would probably only take a fall of five degrees centigrade to wipe out grain production completely. Yet, if war broke out in the Northern Hemisphere's spring or summer, temperatures could drop by as much as 30 degrees centigrade for some months in the most severely affected areas.

Scientists differ over the degree to which the nuclear winter effect would cross the Equator. Certainly the far southern latitudes would be least affected, though the result could still be disastrous. Over 85 per cent of the world's population lives north of the Equator.

The famine resulting from a cooler-than-average growing season over much of the Northern Hemisphere would cause hundreds of millions of people to die of starvation in combatant and non-combatant countries alike.

The nuclear winter syndrome means that any country using nuclear weapons would lose far more, in terms of climatic and environmental chaos, than it could ever hope to gain. It means that nations which would not be targets, notably in the Third World, would still suffer devastation.

And it ought also to mean that nuclear weapons are now unusable.

Sources: Dr Neil Cherry, Scientists Against Nuclear Arms, Aotearoa (NZ), A. Barrie Pittock, Nuclear winter, Victorian Association for Peace Studies, Australia 1984; No Place to Hide: Nuclear Winter and the Third World. Earthscan 1986; Star Wars-File No 1. Greenpeace; Ruth Leger Sivard, World Military and Social Expenditure 1985. Tim Williams, Electronics for Peace UK