Although the response in Western capitals to Russia’s aggressive military posturing on its border with Ukraine has been couched in clear diplomacy-first terms, military contingency planning has stepped up a notch in recent weeks. The intent of these moves, at least judging from the rhetoric of U.S. and NATO leaders as well as respected commentators, is to strengthen deterrence.
Deterrence, as Nobel Prize-winning U.S. scholar, Thomas Schelling, elaborated in his seminal 1966 book, “Arms and Influence,” is meant to prevent an adversary from taking future actions. Schelling distinguished it from a second strategy of coercion, compellence, which is meant to change an adversary’s existing behavior. Neither is foolproof, and both come with risks. But unless the West is clear about which strategy to pursue against aggressive Russian posturing, diplomacy may fail.