Deterrence Strategy versus War Strategy

In a previous article here I discussed the concept of deterrence and whether one can deter the undeterrable. I want to return to that subject by discussing the difference between a deterrence strategy and war strategy. Specifically, I want talk about an essay by one of the very best modern military strategists, the French General André Beaufre. The article is “Stratégie de dissuasion et stratégie de guerre” (“Strategy of deterrence and strategy of war”), published in 1962 in the semi-official French military journal Revue Défense Nationale.

Beaufre opens by noting that the English word “deterrence” has a specific meaning, “to prevent a given action.” The objective of deterrence usually is to preserve peace. If war happens anyway, Beaufre argues, that means that deterrence has failed. At that point, Beaufre continues, one must abandon a strategy of deterrence in favor of a war strategy, the objective being “re-establishing peace.” How? By winning, and by winning at the lowest cost.

Beaufre explains that to win, one must allocate the necessary means, but only the necessary means. Remember, he’s writing in 1962, when “by all means necessary” might mean using nuclear weapons, and people were trying to figure out in what circumstances nuclear weapons should be used, and how to obtain from them the maximum deterrence effect. Normally, he explains, “the use of force is dosed according to the means required to obtain strategic goals fixed by policy.” “One no longer destroys to destroy”—which is part of a deterrence strategy, i.e. the threat to completely nuke one’s enemy if they attack—“but to win.” This was, according to Beaufre, the meaning of General Maxwell Taylor’s concept of a “flexible response,” which proposed a supple response to aggression.

I guess one can say the idea here is proportionality. Beaufre, however, does not talk about proportionality in the sense of “ethical,” the way it is used today. For him, the idea is to use force in a way that is proportional to the risk and what’s at stake. Basically, how important is it to win? If it is very important, then it is appropriate to allocate more resources.

Beaufre explains the concept of “flexible response” in the following terms: By abstaining from destroying some of the enemy’s cities, one maintains a threat of deterrence that might prevent the enemy from destroying one’s own cities. Because one can still destroy the other cities if pushed. Beaufre also talks about responding to a direct threat with a rational fencing match. Fencing has rules, and the intent is not to kill. This is the opposite of that famous scene in the first Indiana Jones movie, where Indiana responds to a threat by a guy with a sword by pulling out his revolver and shooting the man. The idea is to respond to an existential threat by pulling out one’s fencing sword. En garde!

Beaufre concedes that if somehow the enemy is inclined to call one’s bluff, the deterrence value hopefully communicated by a “flexible response” is lost. It is indispensable, according to Beaufre, that the enemy not know if one is serious or not. This is the problem with drawing one’s fencing sword. Also, he reminds us that the choice of means—a sword or a revolver—must be proportionate to the risk and also what is at stake. His concept of a rational fencing match “absolutely does not imply weakness or giving up.” A “flexible response” can be massive.

Beaufre now introduces another concept, the idea of a “sanctuary” versus a “theater of operations.” By sanctuary, he means the geographic space covered by “absolute deterrence.” Basically, the sanctuary is that thing that, if threatened, justifies going to extremes. He has in mind the use of strategic nuclear weapons. By “theater of operations,” he means a geographic space where one must admit an aggression against one’s interests should not trigger an all-out response. Where reaching for nuclear weapons would not be justified. In contemporary language, the favored term is “vital interests.” France, for example, says it will not use nuclear weapons unless its vital interests are at stake. But France also is careful not to define them; it is best to leave potential adversaries uncertain.

Indeed, Beaufre cautions against drawing such clear lines between the “sanctuary” and the “theater of operations.” For one thing, clear lines might even encourage an enemy to be aggressive in ways it assesses will not trigger a maximal response. “We can attack here because they won’t come down hard on us so long as we don’t attack there.” Therefore, one has to be vague about where the lines are, and also be willing and able to respond massively to an act of aggression, even if the means one uses to do so fall short of nuclear weapons. The bad news, of course, is that this view implies the need even for a nuclear power to maintain robust conventional forces, something that originally many had hoped would no longer be necessary.

Beaufre, as I’ve stressed, was writing at the height of the Cold War and was concerned with nuclear deterrence and the prospect of a war that could go nuclear. So what are we to learn from his arguments that we may apply to conflicts today that perhaps are less likely to lead to a nuclear apocalypse?

One is that it is imperative, as it was in Beaufre’s day, for even nuclear-armed nations to retain a full gamut of military capabilities so that they do not find themselves in an “all or nothing” scenario. They must be able to respond, proportionately, to acts of aggression that fall beneath the threshold of justifying a nuclear response. Another is his concept of proportionality. Again, he does not tie the term to any notions of ethics, which is the case today, thanks to many people’s reading of international humanitarian law. For Beaufre, the amount of force one uses in response to an act of aggression must be proportional to the risk and to the importance of what is at stake. And one must be able to communicate to one’s adversary that one is capable of ramping up the amount of force. “If you think this is bad, we can do much worse.”

A third basic idea is that deterrence strategy is not identical to a war strategy. When it comes to a war strategy, the point is, as it always has been, to win. Or at least not to lose. The need for restraint comes from the reality that not every war justifies going all out and unleashing the totality of one’s military power. But that only works if one can still convey the fact that one has not reached the limits of one’s power.