One way to avoid this mixing of systems is to deny that deterrence involves a conditional intent to retaliate at all , thus simplifying its intent structure .sx However the attempt to take intent out of a consideration of deterrence faces formidable obstacles .sx A strategy based on bluff , for example , involves two conditions that appear to be very difficult to guarantee in practice .sx One is that the state in question must have decided , should the bluff be called , not to act on the threat .sx The other is that such a position has to be maintained through time .sx More importantly , a policy of uncertainty ( such as the reality of the bluff ) would seem to be potentially damaging where it extended to others' ability to evaluate a state's will to defend itself .sx It is for this very reason that states choose to institutionalize retaliatory threats in order to make them credible .sx Therefore it is the state's decision to externally bind itself to retaliation which distinguishes a 'conditionally intent' deterrent posture without reference to which we cannot fully describe the strategy itself .sx The strategy is differentiated by its structure of threats , most particularly the conditional intent it embodies .sx A description in these terms is thus warranted by that feature that accounts for its distinctiveness .sx In other words , intent cannot be abstract .sx Bluff cannot be the basis of deterrence and deterrence without the intent to retaliate is not deterrence at all but rather a policy of possession .sx It is the possibility of use of nuclear weapons in this conceptualization of deterrence which justifies the move to examine the principles of a tradition covering the rules of war .sx This move will be justified more fully below , but first it is necessary to explicate the principles of the tradition .sx Just War Tradition :sx Principles and Problems .sx There are three features of the tradition which are worthy of preliminary note .sx First , the meaning of 'just' in the tradition implies that both sides cannot be pursuing a just war in terms which we understand to conform to the conditions above .sx They cannot both claim to be responding to aggression , for example , or both claim to be putting right a wrong or preventing an imminent wrong from arising within the terms of the tradition .sx This may not , of course , prevent either or both from believing themselves to have just cause .sx The second interesting feature is that the tradition thus works from the premise that war can be justified provided that certain conditions are fulfilled .sx In this sense it represents a compromise between pacifist thinking and a more thorough-going militarist attitude to war , itself rooted in a compromise made between the Christian church and the Roman state in order for the former to secure the protection of the state from the fourth century .sx Thirdly , the tradition is notable for a diversity which , in part , is accounted for by the disposition of those who have contributed to its development to see the tradition as practically based .sx This 'fund of practical moral wisdom' does not work from identifiable theoretical foundations but from actual problems that have been encountered in war throughout the history of its development .sx What then are the principles embodied in this tradition ?sx We can identify two groups known as Jus ad Bellum and Jus in Bello .sx The former specifies on what conditions it is right to go to war , whilst the latter governs the conduct of war itself .sx The requirement of Jus ad Bellum is that a state can wage war only in order to right a specific wrong ( which provides it with 'just cause' and 'right motive') .sx This occurs most frequently where a state has been the object of aggression and where no other measures are left open to that state to seek a remedy .sx War must be declared by the legal authority in the state and only where there is a reasonable chance of success , so as to satisfy the condition that hostilities are not permissible as an end in themselves .sx In addition , the good to be obtained must outweigh the harm that such a war will bring .sx War should also be just in the observation of those conditions attaching to the second group of requirements , those of Jus in Bello .sx These latter specify that the principles of discrimination ( or non - combatant immunity ) and proportionality be observed in the conduct of war itself .sx The manner in which we establish the link between the principles incorporated in Jus ad Bellum and those laid down by Jus in Bello is likely to prove of particular importance .sx This is because there is an ineluctable tension between the requirements demanded by the two sets of principles whereby no state is likely to accept limitations on how it may conduct a war in which it believes itself to the justly engaged .sx The acceptability of any such rules will depend , ironically , on their not impinging on the very process they are supposed to control .sx In this respect the conduct of war may be both just and unjustified or unjust and justified , according to the adherence of a state to the requirements set out in the two parts of the tradition .sx Whilst it might seem consistent to argue that it is only when both sets of conditions are fulfilled that a war can be declared just within the tradition , this is nowhere clearly stated .sx Indeed , at no other point does the tradition identify itself more clearly as a tradition of disagreement than on the issue of which of its principles are to be treated as primary .sx This problem also extends to the ordering of the principles incorporated in the Jus in Bello requirements .sx For example , if discrimination is regarded as a categorical or absolute principle , this implies that all wars must be equally condemned and that the just war tradition should be abandoned altogether .sx This follows because , by an absolutist reckoning , the intended death of only one non-combatant is required to prove a war unjust and hence immoral .sx It is argued by way of rebuttal that a categorical principle of discrimination must be rejected on two fronts .sx The practical , more general , objection is that the treatment of discrimination as an absolute principle at the central core of the tradition is implicitly rejected by the Church's continued acknowledgement of the state's right to legitimate self-defence .sx The more theoretical objection is that the attempt to absolutize one principle from the tradition is mistaken since each is a prima facie duty only , neither of which can be abstracted from the relevant 'moral context' .sx If these objections hold good , then it must be admitted that discrimination is not properly founded as a categorical principle at all , and since the tradition is predicated on certain justified uses of force , that the principle of discrimination must be described in instrumental terms .sx However , if this is the case , a 'threshold' of value at which the principle becomes operative requires to be established .sx Since the only terms available are those which the tradition itself provides , this means defining discrimination in terms of proportionality , the other major Jus in Bello principle .sx Yet the effect of so doing is to reduce one principle ( discrimination ) to another ( proportionality ) , such that any prior limiting conditions to the permissibility and conduct of war , whose discovery we most precisely wish to achieve , cannot be established , for .sx " Proportionality whilst more severe a constraint .sx .. does not categorically exclude certain kinds of acts , for any form of violence is permissible if it is supported by the correct cost-benefit calculations .sx And , of course , the principle of proportionality does not itself tell us what is to count as a cost and what as a benefit in making these calculations .sx " .sx The adoption of an absolutist principle ends inevitably in the condemnation of all war and thus a denial of the relevance of the tradition ; yet a relative principle fails to provide decision rules that could guide the application of that tradition .sx If both these positions are as intractable as they appear , how has the tradition been able to proceed over the years ?sx As far as the Christian element is concerned , use has been made of the principle of 'double effect' , which separates the intended effects of an action from effects that are merely foreseen in consequence of that action .sx Thus .sx .sx .. unintended side effects are permissible even if they are foreseen , as long as the intention is good in itself and permitted evils are not disproportionate to the intended benefits .sx " .sx For the principle to apply requires that four conditions be fulfilled .sx First , the two effects - the intended and the 'merely foreseen' - must flow from an act which is morally good .sx Secondly , the good effect must arise immediately from the act and not flow from any evil effects of that act .sx Thirdly , the intention must be directed at obtaining the good but only 'allowing' the evil effect .sx Fourthly , the allowed evil should not be disproportionate to the good intended .sx Given these conditions , the doctrine of double effect can be viewed as the attempt to rescue some 'workable' notion of absolutism without which the Christian ethic 'goes to pieces' .sx However , the application of the doctrine is highly problematic .sx It is full of operational obscurities and lacks adequate definitions ( of dis proportionality , for example) .sx A further difficulty involves the distinction between acts and their consequences ( and of means and ends ) , particularly where the applicability of the doctrine may depend on the description of the act to which we adhere .sx The danger is one of isolating intent from act so as to 'secure purity of intent by an interior act of mind which could be produced at will' .sx Given this , it is not clear that the distinction between the intended and the foreseen is one which is morally relevant .sx To put it differently , how can it be the case that an act , which it is morally impermissible to perform intentionally , could be permissible where those same consequences are a foreseen but unintended product of that same act ?sx These problems arise as a direct consequence of the burden placed on the principle of double effect to resolve incongruities within the just war tradition .sx Not even the application of double effect lets the tradition off the hook ; it cannot hope to retrieve absolutist insights from 'politically relevant' principles by an increasingly heavier reliance on the concept of proportionality .sx Indeed , if there is anything that is held too distinguish the central insight of the Christian ethical tradition , it is that it holds that some acts are absolutely evil in intent .sx If these are , by definition , disqualified as morally correct acts , the descriptive niceties of double effect threaten to bring the writing of those who adhere to it into ethical disrepute .sx Just War Principles applied to a 'Morally Commendable' Deterrent Strategy .sx Prior to trying to apply a tradition with such weaknesses to the 'design' of a deterrence strategy , it is necessary to deal more fully with two objections .sx It may be objected that a tradition concerned with the rules of war is not applicable to strategies designed to prevent war .sx However , deterrence must , by definition , involve some risk of use and it is this risk which allows the application of the tradition to deterrence .sx Following on from this , it may be objected that deterrence is actually designed to prevent a greater wrong from arising ( the 'unconditional' intent mentioned above ) and thus that it could represent a strategy chosen to prevent nuclear use .sx These objections are answered here with four assumptions which , for reasons of space , are more extensively explicated elsewhere .sx The first of these is that morality is obligatory to human existence , such that the apparent options of treating it as superfluous or as inoperable by reason of the imperative of circumstances , are not so much alternatives to , as subsets of , the position which is adopted here .sx Those who believe that states have interests and values to defend are actually stating their belief in the need to postulate concepts of the 'good' by which the state should be obliged to abide .sx Secondly , the possibility of alternative means for defending the state weakens the case for seeing the right to practise deterrence as automatic and thus as the only means to ensure the possibility of the good life .sx