Recently, an author made the argument that the German battleship Bismarck, sunk in May of 1941, was a “waste of resources relative to the combat results they achieved.” Indeed, the author argues the same for the entire surface navy, saying the Kriegsmarine shouldn’t have built its seven large capital ships at all since the raw materials and “factory bandwidth” could have manufactured hundreds or thousands of additional submarines (U-boats), tanks and aircraft for use during the war. Items that were—in the authors view—used to much greater success during the war.

This view is a variation of the sunk cost fallacy, which argues that decisionmakers should not consider previous investments when deciding on a course of action. In this case, the author is arguing that naval weapons platforms designed and built by Nazi Germany during the 1930s should never have been constructed in the first place. As put by the author, Germany was never going to challenge Britain or the United States “for surface ship sea supremacy,” and therefore the resources should’ve been directed into weapons (such as tanks, aircraft, and submarines) more suited for the German way of war. This is not a new argument. Gerhard Weinberg, in his 1994 history A World at Arms, even went a step further, suggesting Nazi Germany shouldn’t have continued building U-boats after 1943 because by then the war at sea was “already lost.”

A few moments thought, however, reveals the post hoc fallacy inherent in both these positions. In the case of U-boat construction in 1943, the argument ignores both the strategic context of the war at sea and the real cost of retooling manufacturing for other purposes. Other than raw steel and generic machine tools, most components used in mid-twentieth century warship construction are specific to shipbuilding needs. Very little engine, piping, fittings, electronics, weapons, and ship armor capacity can be diverted to building tanks or airplanes, let alone shipyards themselves. Secondly, the argument ignores the effect of U-boat operations even when merchant ships aren’t being sunk in large numbers. Simply by deploying in the vicinity of convoy routes, U-boats tied down Allied surface escorts and patrol planes in very large numbers, tying up many more Allied resources than Axis (in a roughly 10:1 ratio). From a resource allocation perspective, Weinberg was simply wrong when he claimed the war at sea was lost in 1943. Instead, the Kriegsmarine was correct in putting U-boats to sea up until the last day of the war.

Returning to the 1930s, the argument that the Germans shouldn’t have built a surface navy which would just be sunk a decade later is an even worse post hoc fallacy. First, navies are typically built during peacetime and are designed to serve the expected peacetime and wartime needs that best serve a nations strategy. Future wars are unknown, obviously, and while one can build against likely enemies the future often turns out different than you planned. Based on many centuries of experience, nations tend to build balanced fleets (comprised of many different types of warships) as these are best able to adapt to changing circumstances. They are also best suited to serve as an arm of foreign policy. Policy-wise, the Kriegsmarine was not wrong to build surface ships.

Capital ships are also huge economic undertakings, costly in time (30,000-plus man-hours), resources and money. They are typically built in peacetime, both because they take years to finish and so the labor and resource costs can be amortized over time. They are also very often political jobs programs—there’s a reason the first six frigates in the United States were each built in a separate state, that battleship modernization in the United States took place starting in 1934 and why shipyards and defense industries are still spread geographically across countries even today. Domestic spending on navies today is clearly subject to political wrangling, and the same rationale applies to the Kriegsmarine in the 1930s.

Lastly, we can dispose of the Bismarck resource use argument. As noted above, reallocating resources from one industrial operation to another is not easy. But even if it were possible in the 1930s (unlikely as noted above), any reallocated factory bandwidth was not going to build advanced fighters, heavy tanks or wartime effective U-boats because these platforms simply did not yet exist. Indeed, designers needed the hard lessons learned in combat before Focke-Wulf fighters of Tiger tanks could come off the drawing boards. Instead, Germany would’ve simply gotten more 1930s-era weapon systems that would still need wholesale replacement in the early 1940s anyway.

Post hoc fallacies in a historical context are pernicious because they treat the vagaries of history, with all its twists, turns and random chance as prejudged and preordained. They remove agency from the people who lived through those times, who made decisions based on incomplete information and whose questions, arguments and plans were made facing an unknown future. This does not mean we shouldn’t learn from the past—state-level decision-making should be informed by past choices, especially bad ones—only that we should not criticize the dead too much for not knowing the future.

Dr. Timothy L. Francis was a naval historian at the Naval History & Heritage Command in Washington, DC. He also served twenty years as a Navy reserve intelligence analyst. The views expressed in this essay are his alone and do not represent the views of the Department of Defense.

Image: Wikimedia.