Following up my last post.

Game theory and the Schliefen Plan: Part Two

Assuming that both Germany and Russia were rational actors at the start of World War One, Germany must have had a perspective on its payoffs for going to war with Russia in support of Austria versus not going to war and allowing Austria to be defeated that caused “war” to be the rational choice at the time. Despite the horror of war, and in hindsight the particular horror of World War One, Germany acted on the time-tested practices of sticking with good, reliable, military allies (Austria) and not allowing timeworn enemies (Russia) to increase its sphere of military and diplomatic influence – which a military victory over the Austrians would certainly do. Additionally, at the start of World War One very few military minds had any idea of the military quagmire that would result from the first major applications of chemical weapons, new artillery weapons and techniques, the massed use of machineguns, and the contrary fortunes of war. However, in deciding to go to war with Russia, Germany acted as if expecting that no other nation would use the same thought process and logic in deciding whether to declare war on Germany as a result of German military actions.

The Schliefen Plan was the plan by which the entire German nation would go to war. As a result of the political and military climate, the only conceivable situation was one in which Germany would find itself fighting both France and Russia simultaneously. As France was expected to be able to mobilize an effective army and invade Germany sooner, the Schliefen was fully structured around the idea of swinging all possible German military might against France and knocking them out of the war within six weeks, then rapidly moving the German army to the eastern front and confronting Russia. Such was the inflexibility of the Schliefen Plan that if Germany found itself facing imminent conflict with Russia, they would be forced to attack France. This firm commitment was expected to give France cause to exert pressure on their ally, Russia, to stay in line.

So when Germany decided to honor their treaty obligations with Austria, they found themselves virtually required to attack France and force a peace as quickly as possible – though France was not initiating conflict nor even threatening to do so (why not just skip to the “move the army east” phase I don’t understand). The German staff felt that their best chance at a quick victory in France lay in attacking through Belgium.

Though the Belgian people and king had taken a strong posture of fighting to maintain complete sovereignty, Germany expected that as German troops actually crossed the border the Belgian government and military would accede to German demands for uncontested passage through the little nation. After all, the whole point of such posturing is to keep other nations out, not cause the devastation of your own nation by refusing to allow passage once the invader is already in, right? Game theory sub-game perfection would say yes, once it is clear that your initial strategy has not worked, do that which is most advantageous. Instead, Belgium fought – and they did not fight alone.

Belgium had recently signed a treaty with Great Britain stating that the British would both respect Belgian neutrality/sovereignty and exert military force to ensure others did as well. Despite knowledge of this treaty, the Germans, using game theoretical reasoning similar to that above, in no way expected England to actually go to war over “a mere scrap of paper”, instead expecting that England would back down from the treaty once Germany actually invaded Belgium and Great Britain saw that war was reality. In short, though the Germans seem to have violated basic precept of game theory in going to war, they expected both Belgium and England to adhere to sub-game perfection and allow Germany to march through Belgium unopposed.

What this tragic episode from history show us it not a failure of game theory, but rather, assuming rational actors, that incentives and perceived payoffs must be clearly understood by all involved. Information is key. For the Germans, it made the difference between a quick victory over France and a long drawn-out catastrophic defeat.