Until recently, nuclear deterrence was not a fashionable topic of conversation. The fall of the Berlin Wall, the break-up of the USSR and the appearance of asymmetric warfare and terrorism as patterns of armed conflict in the closing years of the last century and the opening years of this, all gave the so-called new strategic thinkers cause to persuade us that nuclear deterrence was at best an outmoded concept, at worst a dangerous artefact of the past. And yet . . .

Deterrence Remains as Relevant Today as Ever

Deterrence is as old as man himself. It is founded on a set of unchanging aspects of human behaviour, regardless of era, civilisation, beliefs or political system, whose nature is such that men and governments take into account the probable consequences of their intentions and actions before putting them into practice. Because of this, they generally tend to refrain from taking action where the negative consequences for themselves, the cause they support or the interest they defend, risk outweighing the potential gains. Put another way, in the language of game theory, deterrence is founded on cost-benefit analysis.⁽¹⁾ What make nuclear deterrence so special are the intrinsic characteristics of nuclear weapons.⁽²⁾ Their destructive capability is such that only the most perfect protection against their effects would guarantee that an aggressor’s cost-benefit analysis would favour a gain on his part. Perfect protection, however, simply does not exist.

The role of nuclear weapons and nuclear deterrence is neither limited nor even principally intended to deter the use of nuclear weapons. According to the concept developed in the West over the past 60 years, at least, it is rather to deter war itself, as well as the use of those traditional tools of the pre-nuclear age, intimidation and blackmail, backed up explicitly or otherwise by military force.⁽³⁾ In this respect, twentieth century experience in Europe and Asia should make us bear three things in mind. The first is that, other than war itself, countries wanting to challenge world order have repeatedly used intimidation and blackmail, whether or not openly backed up by military force, as a substitute for war or, more often, as a prelude to it. In today’s world the spirit of war has virtually evaporated from Western or Westernised societies, which have become pacifist to a degree never before achieved in history. In them, the employment of institutional violence, whatever the context, be it domestic or external, is subject to widespread suspicion.⁽⁴⁾ In such circumstances, intimidation and blackmail can be used insidiously to achieve political aims or to acquire or create spheres of territorial influence.⁽⁵⁾