The Assumptions of British Nuclear Weapons Decision-Makers

Particular decisions about nuclear weapons are made by individuals on the basis of a set of assumptions. These assumptions are rarely revealed in official publications which explain or support those decisions. But without knowing what these assumptions are it is impossible to test the validity of the decision-makers' arguments, or to know what kind of debate with them is likely to be fruitful or effective. This paper describes the assumptions made by a small group of influential British nuclear weapons decision-makers. The research on which it was based was carried out in four stages. First each decision-maker was interviewed at length. Next, the statements made in the interview were assembled into a cognitive map in order to find those assumptions which were not articulated or which were hidden in chains of reasoning, the use of analogies or the structure of the whole system of thought. Next the maps were compared to find the commonalities shared by all decision-makers and to isolate the critical assumptions. Finally, the identification of these assumptions as critical was tested by interviews with knowledgeable critics of nuclear defence policy. The most important assumptions are as follows. Nuclear weapons are not qualitatively different from conventional weapons. Decision-makers in all the nuclear nations are rational and in control of the weapons. Because they are rational it is assumed that the system of deterrence as a whole works rationally and is stable. Indeed, it is so stable that any change is dangerous and it should remain unaffected, in particular, by any reduction in the perceived threat. The paper does not discuss the validity of these assumptions, but considers their implications for change.