Proportionality and deterrence

There are many contexts where a necessary condition of the permissibility of a course of action is a kind of proportionality between the goods and bads resulting from the course of action. (If utilitarianism is true, then given a utilitarian understanding of the proportionality, it’s not only necessary but sufficient for permissibility.) Two examples:

• The Principle of Double Effect says it is permissible to do things that are foreseen to have a basic evil as an effect, if that evil is not intended, and if proportionality between the evil effect and the good effects holds.

• The conditions for entry into a just war typically include both a justice condition and a proportionality condition (sometimes split into two conditions, one about likely consequences of the war and the other about the probability of victory).

But here is an interesting and difficult kind of scenario. Before giving a general formulation, consider the example that made me think about this. Country A has a bellicose neighbor B. However, B’s regime while bellicose is not sufficiently evil that on a straightforward reading of proportionality it would be worthwhile for A to fight back if invaded. Sure, one would lose sovereignty by not fighting back, but B’s track record suggests that the individual citizens of A would maintain the freedoms that matter most (maybe this is what it would be like to be taken over by Alexander the Great or Napoleon—I don’t know enough of history to know), while a war would obviously be very bloody. However, suppose that a policy of not fighting back would likely result in an instant invasion, while a policy of fighting back would have a high probability of resulting in peace for the foreseeable future. We can then imagine that the benefits of likely avoiding even a non-violent takeover by B outweigh the small risk that despite A’s having a policy of armed resistance B would still invade.

The general case is this: We have a policy that is likely to prevent an unhappy situation, but following through on the policy violates a straightforward reading of proportionality if the unhappy situation eventuates.

One solution is to take into account the value of follwing through on the policy with respect to one’s credibility in the future. But in some cases this will be a doubtful justification. Consider a policy of fighting back against an invader—at least initially—even if there is no chance of victory. There are surely many cases of bellicose countries that could successfully take over a neighbor, but judge that the costs of doing so are too high given the expected resistance. But if the neighbor has such a policy, then in case the invasion nonetheless eventuates, whatever is done, sovereignty will be lost, and the policy will be irrelevant in the future. (One might have some speculation about the benefits for other countries of following through on the policy, but that’s very speculative.)

One line of thought on these kinds of cases is that we need to forego such policies, despite their benefits. One can’t permissibly act on them, so one can’t have them, and that’s that. This is unsatisfying, but I think there is a serious chance that this is right.

One might think that the best of both worlds is to make it seem like one has the policy, but not in fact have it. A problem with this is that it might involve lying, and I think lying is wrong. But even aside from that, in some cases this may not be practicable. Imagine training an army to defend one’s country, and then having a secret plan, known only to a very small number of top commanders, that one will surrender at the first moment of an invasion. Can one really count on that surrender? The deterrent policy is more effective the fiercer and more patriotic the army, but those factors are precisely likely to make them fight despite the surrender at the top.

Another move is this. Perhaps proportionality itself takes into account not just the straightforward computation of costs and benefits, but also the value of remaining steadfast in reasonably adopted policies. I find this somewhat attractive, but this approach has to have limits, and I don’t know where to draw them. Suppose one has invented a weapon which will kill every human being in enemy territory. Use of this weapon, with a Double Effect style intention of killing only the enemy soldiers, is clearly unjustified no matter what policies one might have, but a policy to use this weapon might be a nearly perfect protection against invasion. (Obviously this connects with the question of nuclear deterrence.) I suppose what one needs to say is that the importance of steadfastness in policies affects how proportionality evaluation go, but should not be decisive.

I find myself pulled to the strict view that policies we should not have policies acting on which would violate a straightforward reading of proportionality, and the view that we should abandon the straightforward reading of proportionality and take into account—to a degree that is difficult to weigh—the value of following policies.