Could the much-maligned cuts to defense spending actually be a good thing for American strategy? That’s the case that historian Melvyn Leffler makes in the most recent issue of Foreign Affairs. Responding to those who argue that past retrenchments have left the military ill prepared to respond to future dangers and stress the need to avoid doing the same today, Leffler argues that these fears are overblown. In his words:

Contrary to such conventional wisdom, the consequences of past U.S. defense cuts were not bad. In fact, a look at five such periods over the past century—following World War I, World War II, the Korean War, the Vietnam War, and the Cold War—shows that austerity can be useful in forcing Washington to think strategically, something it rarely does when times are flush.

The argument, in a nutshell, is that when the government is operating under constrained resources, it is forced to make more difficult choices and prioritize more effectively, leading to better strategy. It has a certain intuitive plausibility to it, but the examples he presents don’t really seem to support it.

Take the most infamous one—the U.S. military drawdown after World War I, which is often held to have left Washington unready for World War II as the fighting broke out in Europe and Asia. Not so, says Leffler. Rather, “When a second global war did come, the paucity of the resources on hand actually forced U.S. policymakers to make tough but smart strategic choices.” Thus, led by Harold Stark, then chief of naval operations, the U.S. government embraced a threat assessment that judged that the “principal threat to U.S. security was German power.” It allocated resources accordingly, focusing first on helping the United Kingdom to avoid defeat at Germany’s hands while simultaneously building up its own military power and “using diplomacy to avoid war with Japan.”

No doubt this approach has been vindicated by history. Yet while Leffler says that it was “a combination of austerity and crisis [that] helped forge a core strategic concept,” it seems abundantly clear that the crisis alone was the real driver. After all, defense spending had been comparably low for the two previous decades, but that didn’t mean that officials were doing particularly deep strategic planning before 1940. Indeed, as Leffler notes, during that time they embraced a “flawed threat perception” that downplayed the danger from Germany and Japan. The result was that, on the eve of war, the United States had only the sixteenth-largest military in the world. The crisis was grave enough that it would have certainly prompted some kind of rethinking no matter what shape the military was in at the time, but Leffler never gives us any concrete reason to think that the lack of military resources was a net asset for Franklin Roosevelt and his team. U.S. planners succeeded in spite of the resource limitations they faced—not because of them.

This account is meant to support the view that we ought not fear defense austerity today. However, if one wants to make the case for cutting defense spending now, the best arguments for doing so are those that stem from long-range thinking rather than asserting that the cuts themselves will spur better planning. Such an argument might run like this: The United States is a very secure country. It dominates its own hemisphere. It spends more on its military than the next ten countries combined—and many of those countries are its allies. America has adversaries, but its rival great powers are far less dangerous than those of the past. Thus, there is room to cut the U.S. defense budget to right-size it to the threats it actually faces, while still enabling it to maintain preponderant military strength. The money saved could then be used to accomplish any number of other national priorities.

Whether or not you find this line of thinking persuasive, the point is that it starts with an assessment of what the world and the international threat environment actually look like. It doesn’t start with a budget number and then assume that officials will be able to re-prioritize to figure things out within that constraint. In short, if we’re going to cut our military budget, we should do it in the service of a concrete goal rather than just hope that doing so will spur our future leaders to do better long-range thinking of their own.