Eye-catching title of the course aside, today we finally covered a stretch of time that truly is one hundred years ago today: the First Battle of Ypres. Here, we saw some of the first strong hints about what entrenched, attritional warfare would look like once the Western Front stabilized. First Ypres was (for this part of the war) a long, drawn-out struggle that would leave many dead and very little territory in different hands, highlighting what would become for many the war’s central tragedy, a major puzzle, and a bone of violent contention in post-war politics in the former belligerents: why engage in such an ostensibly “futile” strategy like attrition, which promised only death, destruction, and disillusionment—certainly not a conventional notion of victory—on a large scale?
Some answers, especially those offered right after the fact involving “unimaginative” generals insensitive to casualties, are probably too easy (that they came from politicians seeking to distance themselves from an unpopular strategy should tell us something here). We argued today that it’s worth approaching the puzzle of attrition in a different light—by thinking about the options available to strategists given terrain, the seer size of the front, and the state of technology and doctrine. Doing so gives us a better sense of why attrition was adopted by both sides, why it was stable, and what it took to induce a change in strategies and a return to maneuver in the last months of the war.
Our argument went something like this. Modern firepower favored the defense when attackers used then-contemporary tactics (that is, no or poor uses of combined-arms), and local successes were virtually impossible to turn into wider breakthroughs, because (a) capturing even a small section of the opponent’s trench depleted so much manpower that the attacker was then vulnerable to counterattack, thanks to (b) the rapid movement of reserves behind the front by rail. With breakthroughs nearly impossible, winning became a matter of wearing the enemy down, of grignotage—that is, exhausting the other side’s reserves of manpower by maintaining persistent pressure on the front, or, as General Sir Douglas Haig would say, simply “killing Germans.” To be sure, attrition was ghastly, costly, and damaging to both individuals and the societies supporting them in the field; but disapproving of it doesn’t get us off the hook for explaining it.
In fact, we build a simple theoretical structure today to show that a tragic, costly equilibrium of attritional warfare can set in as the best option in a pack of alternatives that, unfortunately, might all be worse. To be in equilibrium, two strategies must be adopted by players that have no incentive to deviate from them, given what the other side is doing, and attrition looks just like that in many cases. If the side A is maintaining pressure on the front—a front that doesn’t allow maneuver and where the defense prevents major breakthroughs—then side B’s alternatives are to fight back and maintain the pressure or to slack off; the latter, of course, makes breakthroughs actually possible by eliminating the advantage of the defense. However, if side A isn’t maintaining pressure, side B can’t afford not to take advantage of it—meaning that both sides, under the technological and, to a lesser extent, doctrinal strictures of 1914, had a dominant strategy of maintaining pressure on the opponents in the other trenches, wearing their reserves down until such time as the defense would no longer be dominant. Therefore, attrition was an equilibrium, one that made sense for both belligerents, not one we’re obligated to be comfortable with in a normative sense—but one that we can explain: no side had an incentive to deviate from a strategy of attrition until the offense could regain some kind of advantage, until attacking and gaining territory could result in anything other than horrendous losses in the face of determined counterattack.
If we can explain what makes attrition an equilibrium, we can also explain its stability (the continual but generally vain searches for alternatives, such as opening additional fronts) and what would ultimately break it: the ability to achieve and sustain a breakthrough, which came as the result of the exhaustion of the German Army’s reserves and effective combined-arms tactics developed and honed over the course of the war. The first factor, of course, came about as the result of attrition, of wearing out German reserves faster than they could be replaced (possible due to Allied advantages in demography and aggregate wealth). We can also ask whether attrition was “futile,” and seeing it in a strategic light, the question is not so easily answered as common stories have it. Relative to laying down on the Western front, as well as to efforts that would not wear down the opposing side’s reserves (say, the Gallipoi offensive), it’s hard to say that attrition was the worst possible option. Was it futile in the strategic sense? Probably not; it might just have been merely the least-horrific alternative in a world of even more intolerable ones.