A review of Castles, Battles, and Bombs: How Economics Explains Military History, by Jurgen Brauer and Hubert van Tuyll

Why do men fight the way they do? Few questions are more fundamental to an understanding of military history. To begin with, simple environment and geography must explain a lot. We know why landlocked Switzerland never matched the British Navy; and why German tribesmen fought in thick hides and fur against Roman legionaries across the Rhine, rather than near-naked like tribesmen in the tropics battling European colonialists. Mass chariot tactics made sense in much of the Middle East, but less so in the tiny inland valleys among the feuding Greek city-states, where terrain was often difficult and pasture land for horses rare.

Culture accounts for far more. A centuries-long tradition of Western science, rationalism, and free markets explains in large part why, in 1519, Hernán Cortés sailed into Vera Cruz, rather than Montezuma with an Aztec imperial fleet into Barcelona. Western rationalism also explains why British redcoats were better supplied with food and ammunition in distant Zululand than were King Cetshwayo's impis in their native plains—gallant warriors who nonetheless lacked the knowhow to manufacture Martini-Henry Rifles and ocean-going ships.

Individual genius can at times influence even these larger forces. Had Philip II of Macedon lived, perhaps the Macedonian army might have invaded Persia and taken Babylon; but without the subsequent leadership of Alexander the Great it would never have gone eastward beyond Persepolis, much less ended up on the Indus River—and much less still laid the foundations of the Hellenistic World. Take away the singular mind of Napoleon, and the revolutionary French nation in arms would not have fought British, Prussian, or Russian enemies so far from the borders of an imperial France. It is hard to think of any other Northern general who would have envisioned William Tecumseh Sherman's devastating marches through Georgia and the Carolinas. The decision to send high-altitude, precision B-29 bombers on low night runs with incendiaries that would burn down the cities of Japan is difficult to conceive without the looming presence of maverick General Curtis LeMay. I think without the success of David Petraeus, Congress would have shut off funding for the Iraq War by early 2008.

Chance or pure luck on rare occasions affects the outcome of battle. Had the Japanese fighter squadrons at the battle over the Midway islands not swarmed lumbering, low-flying American Devastator torpedo bombers, unseen dozens of higher-flying Dauntless dive bombers above might never have enjoyed relatively unopposed lethal bombing runs against Japanese carriers. A number of "What If?" books speculate about what might have happened at key battles from Salamis to Gettysburg and how, had a single event transpired differently, both the battle and the war in question could have turned out far differently.

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Jurgen Brauer and Hubert van Tuyll, economists at Augusta State University, grant that these various factors affect battle, but insist that their influence is secondary to the laws of economics, which are simply neglected by most military historians. Castles, Battles, and Bombs: How Economics Explains Military History is an all-encompassing exegesis of why military affairs turn out the way they do—an explanation that seems to trump environment, culture, individual genius, and chance. Economic rationalism, or rather just a few ironclad laws of economic reality, determine throughout history the nature of mass fighting. Such principles, the authors argue further, operate cross-culturally and universally across time and space, even when military thinkers and planners themselves are hardly cognizant of them.

Brauer and van Tuyll identify six basic economic principles that guide warmaking, and offer six corresponding historical examples that illustrate them at work. They warn of the arbitrariness of their narrow selection, but nonetheless shrug:

How representative are our six cases of the larger enterprise of infusing military history with economics? We do not yet know. We do know that by selecting six economic principles, rather than just one or two, and applying them to six distinct historical epochs stretched across one thousand years of history, a time period that is ambitious to cover, we have spread the dragnet widely.

Six examples, of course, hardly qualify as "widely," but to be fair, the authors cite in passing dozens of examples that expand the frame of reference.

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They start with "opportunity cost"—or the price of passing up other viable alternatives. Historians have often been confused by the epidemic of expensive castle-building throughout much of Europe between roughly 1000 and 1300 A.D. Why did small states and clans nearly bankrupt themselves to build enormously expensive stone fortresses, often in close proximity to one another?

Usual explanations range from the nature of European political fragmentation, to irrational considerations of status and even royal vanity. But Brauer and Tuyll suggest castles made perfect economic sense—given the expensive alternative of fielding armies in such times. Without large population bases and strong central government to finance and draft manpower at will, medieval rulers found that just a few men ensconced on impregnable stone ramparts proved to be pretty cheap—and eventually justified the initial steep investments in castle construction. In the era before gunpowder, garrisons inside stone fortresses usually outlasted sieges and more numerous besiegers. In other words, when one examines all the other medieval military options, costly castles turn out to be relatively economical.

The conclusion seems persuasive if not entirely original, but one would have wished to see whether such rational calculation applies to other eras of fortification. Did the French after World War I find the Maginot Line the most logical investment of national resources given the alternatives? Or were they uniquely captive of a defensive—and in some sense irrational—mentality that grew up after Verdun, an attitude that German military thinkers escaped sufficiently to allow them to invest in Panzers and a more effective warfare of mobility? Did the Athenians invest in Attic border forts in the 4th century B.C. because it was the most economical way to protect Athenian territory, and made more economic sense than hoplite armies, cavalry, light-armed skirmishers, or navies? Or, as the losers in a 27-year-long Peloponnesian War, were they so traumatized from land invasion that fortifications seemed to be the most reassuring way to keep out any more armies advancing from Boeotia or the Peloponnese?

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Choices in war also in various ways reflect expected marginal benefits and costs. In a chapter on the hired mercenaries of the Renaissance, the authors demonstrate that the so-called condotierri who flourished between 1300 and 1600 were not so improbable as their legendary shortcomings of small numbers, fickle allegiance, and questionable lethality suggest. Sophisticated legal contracts of service allowed small financially-strapped Italian city-states to efficiently special-order the sort of forces they needed, specifying exact weapons, numbers, and length of service. Yet again, had the authors adduced more examples of mercenary service from ancient to modern times, this exegesis of marginal benefits and costs might have seemed a more convincing explanation for the rise of mercenaries (instead of traditional considerations like economic depression, an existing pool of unemployed ex-soldiers, and promises of booty and lucre from conquest).

Between 1600 and 1800 emerging nation-states began to fight more frequent, major pitched-battle engagements, culminating in the massive campaigns of the French national armies of Napoleon. Why this growing preference for bloody pitched battles? The authors once again suggest the role of classical cost-benefit analysis that resulted in the biggest bang for the biggest buck. European states increasingly saw that, given the enormous costs of raising and deploying national armies, they could be used most efficiently to achieve dramatic political objectives through a single climactic engagement—mercenaries or fortifications could not deliver such dramatic changes of fortune.

In the American Civil War, Brauer and van Tuyll see victory in the east, in the see-saw battles between Grant and Lee following April 1864, as hinging ultimately on asymmetrical information—or which side would eventually gain the greater knowledge of the capability and intention of the other, and then make the more informed choices. In the beginning Lee's remarkable intuition and reading of Union commanders gave the Confederates enormous advantages that made up for their inferior manpower and materiel—until Grant nullified these advantages by using greater Northern resources to invest in balloons, telegraphs, and legions of spies.

In a fifth example—of diminishing returns—the authors examine the controversial allied strategic bombing campaign against Europe. The controversy is no longer whether the British and American bombers radically reduced German military production—in fact, the total industrial output of the Third Reich increased despite the vastly increased tonnage dropped during the last two years of the war. Rather the argument rages about the degree to which Allied bombing diverted German artillery and aircraft resources, and increased production costs of relocated factories, together vastly weakening the overall German war effort. Brauer and van Tuyll, however, cast doubt on all that by citing the economic law of diminishing returns. A better way of adjudicating the question, they argue, is to emphasize the increasing allied investment in air crews and planes necessary to achieve only marginally better results. The vast resources allotted to strategic bombing resulted in only incremental and temporary reductions in Nazi industrial production, they argue, and so might have been better invested elsewhere in other services and strategies that could have resulted in comparatively far greater damage to the enemy.

Yet we are never quite told whether the problem was the idea of strategic bombing itself, or the specific obstacles inherent in carrying out the strategy with British and American bombers and tactics of the age against the Third Reich (in contrast, say, to using huge, napalm-laden B-29 superfortresses against the largely wooden, flammable, and poorly defended cities of imperial Japan). The authors hint at, but do not explore fully, the notion that the postwar reconstruction and rehabilitation of Germany may have had something to do with the fact that the shell-shocked German people, unlike at the end of World War I, knew that they had been collectively beaten and had paid a terrible price for supporting Hitler's National Socialist Party agenda.

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The six case studies culminate with the French decision to produce nuclear weapons during the 1960s. This chapter serves as the classic example of the principle of substitution of capital and labor. It is a close examination of the notion that the nuclear option, by the deterrence it provided, and the international status that that accrued, supposedly was worth the diversion of enormous sums from France's conventional forces.

The authors, however, suggest that French prestige suffered more from its inability to project short-changed conventional forces in places like Algeria, Suez, and Vietnam, than it gained from stockpiling over 300 atomic bombs. France's much vaunted force de frappe, for all the talk of French nuclear autonomy, was mostly redundant of NATO's formidable strategic nuclear forces. Thus Charles de Gaulle's decision to build the bomb was probably unwise, since it is hard to see how French political objectives were enhanced by this exorbitant new option.

In economic terms the authors make excellent points but throughout their study it is hard to calibrate to what degree states and leaders think rationally, and to what degree their emotions, intuitions, and mistakes still prove determinative in military calculation. Like it or not, at least part of French nuclear thinking was that Europe had nearly been destroyed on two occasions in the 20th century, and France herself invaded and occupied, at least in part, by Germany three times within a 70-year period. We don't know to what degree the possession of nuclear weapons by a European continental power, along with NATO and the European transnational government, has contributed to a cessation of such violence in the subsequent 70-year interval—only that it would be insane for any European country now to invade a nuclear France. Someone from Mars might examine the past 140-year era, note the bloody first half of carnage on French soil, and then the relatively tranquil second half—and conclude that French nuclear deterrence played some role.

In their final chapter, Brauer and van Tuyll discuss how their six economic laws operate in disputes of our times, such as those about strategies to combat terrorism, the rise of military contractors, and the phasing out of the draft. Throughout their study the authors take great pains to repeat qualifiers and caveats—concerning the arbitrariness of their historical examples, the possibility that more than a mere six economic laws determines military practices, and the role of other irrational determinants in warfare. The result is a curious mixture, perhaps best summed up in their concession: "economic rationalism is mostly behind apparently inexplicable military decisions—but we would not wish to rule out other considerations as well."

Although Castles, Battles, and Bombs can at times be dry reading, and the authors sometimes emphasize economic rationalism at the expense of age-old Thucydidean considerations like honor, fear, and apparent self-interest, they are to be congratulated for adding an imaginative, logical, and hitherto mostly ignored explanation for the apparent irrationality of wars and warmaking. When they apply their theories to the present, Brauer and van Tuyll take much of the emotion and partisanship out of contemporary discussions, showing how many controversial choices are in fact guided by economic necessities rather than supposedly shallow and bad men.