ONCE THE U.S.-Russian relationship enters the zone of heated confrontation, senior military officers on both sides will inevitably play a greater role. As the world saw in the lead-up to World War I, when the security dilemma takes hold, what look like reasonable precautions to one side may well appear as evidence of likely aggression to the other. Clausewitz describes the relentless logic that pushes each side toward “a new mutual enhancement, which, in pure conception, must create a fresh effort towards an extreme.” Commanders have to think in terms of capabilities rather than intentions. This pushes them toward steps that are tactically prudent but that invite strategic misinterpretation.

Predictably, leaders and their military advisers will also miscalculate. Before World War I, Kaiser Wilhelm II did not believe that Russia would dare to go to war because its defeat by Japan less than a decade earlier had demonstrated the Russian military’s incompetence. At the same time, Russian defense minister Vladimir Sukhomlinov was assuring the czar that Russia was ready for battle and that Germany had already decided to attack. As Sukhomlinov said in 1912, “Under any circumstances the war is unavoidable and it is advantageous for us to start it sooner rather than later . . . His Majesty and I believe in the army and know that the war will only bring good things to us.” In Berlin, the German General Staff also argued for quick action, fearing the impending completion of a new network of rail lines that would allow the czar to move Russian divisions rapidly to Germany’s border. After the assassination of Archduke Franz Ferdinand, as the crisis intensified, military commanders in both Russia and Germany rushed not to be the second to mobilize. As the Russian General Staff told Nicholas II, only an immediate and full-scale mobilization would prevent a quick defeat, if not of Russia itself, then at least of France, whose long-term support Russia needed to withstand the German assault.

LATVIA, ESTONIA, and Lithuania form the Achilles’ heel of the NATO alliance. They are protected by its Article 5 guarantee that an attack upon one will be regarded as an attack upon all. Thus, the United States has an unambiguous and undeniable responsibility to deter and defend attacks on the Baltic states. Given their size, proximity to Russia and substantial Russian-speaking minorities, this is a daunting requirement. It is not difficult to imagine scenarios in which either U.S. or Russian action could set in motion a chain of events at the end of which American and Russian troops would be killing each other.