Symbolic victories and strategic risk

Introduction

What makes a battle significant? Clearly, some battles are more important than others. Criteria to distinguish important battles from unimportant ones, though, are not so obvious. ¹ This article expands the literature on bargaining and war to offer one possible criterion: rational symbolism. A symbolic victory becomes more important than other battles by communicating more information. Aware of this potential, a leader can artificially create the conditions for a symbolic victory by deliberately increasing strategic risk. A bold attack against a dangerous objective can separate a strong actor who is willing to accept the risk from a weak actor who is not. Doing so can facilitate negotiation by signaling to an enemy; it can also improve morale and shore up alliances by signaling to friendly and neutral parties. In short, strategists can calibrate military risk to send political messages to allies, enemies, and their own citizens.

Many engagements derive their significance from the information they communicate, not their military impact. In US history, the best example is perhaps Washington crossing the Delaware: while militarily the subsequent victories were minor, they signaled that Washington’s army was stronger than it had seemed before. Washington wished to demonstrate American capabilities to a worried and (justifiably) skeptical public, and he succeeded. Later, Saratoga would play a similar role, giving the French sufficient confidence in American capabilities to join the Revolutionary War. In the case of Saratoga, this symbolism, while immediately recognized by both the Continentals and the French, was probably not the primary reason for fighting the battle; the engagement followed as much from military as political imperatives. Yet, because battles can serve as effective signals, political leaders have an incentive to choose their battles to capitalize on their potential information. Leaders can deliberately seek what, elsewhere, happens by chance. They can deliberately seek to create symbolic victories.

To study the rational side of symbolic victories, I turn to bargaining models of war. Like Clausewitz, bargaining models begin with war’s political dimension, and so they treat battles as stages in a process of costly negotiation. ² As an instrument of rational, political bargaining, war can have two explanations: either the belligerents disagree about their relative strength/resolve (an information problem) or one belligerent cannot credibly promise to honor an agreement in the future (a commitment problem). ³ Because it can address these problems, war, though a last resort, can still offer an effective tool for political bargaining. ⁴

Following this reasoning, we might conjecture that important battles are ones that do more than others to address these underlying political problems. Bargaining models, though, have paid relatively little attention to battles themselves. Especially among formal modelers, the tendency to simplify the choice of battlefields has led to the treatment of battles as equally significant (or insignificant). To begin addressing this gap, I present a formal model in which military leaders are able to choose their battlefields. This choice helps recover some of the symbolism inherent in leaders’ wartime decisions. These decisions allow battles to communicate substantially different amounts of information, showing how some battles might do more than others to solve the informational origins of war.

To illustrate the model, I study two famous encounters, one from the modern world, one from the ancient: the Doolittle Raid and the Second Punic War. In both cases, strategic planners deliberately pursue unnecessarily dangerous engagements to alter the rational expectations of key political actors. Both cases involve militarily inconsequential battles that, nevertheless, greatly affected actors’ strategic calculations. I use the mismatch between military and political value in these cases to isolate a more general phenomenon: battles involving substantial danger often communicate substantially more information. Many strategists, aware of this fact, boldly (or recklessly) increase strategic risk in order to enhance the information their strategies reveal.

Of course, part of a battle’s symbolism is non-rational. ⁵ This non-rationality, though, should not lead us to neglect its rational dimension. Concepts like morale and confidence are psychological in nature, but they also reflect rational expectations. In his work on focal points, Thomas Schelling theorized that competitive equilibria would tend to rest on ideas with imaginative salience – that rational optimization would center on fundamentally aesthetic concepts (Schelling, 1963: 57–58). In that spirit, this article deals with the rational side of symbolism, not to understate or dismiss psychology, but to show how the rational and non-rational might be more intimately related than often recognized.

Game theory offers an excellent and underused tool to conceptualize battles as a means of communication. Within the formal literature, an established and flourishing tradition explores signaling and crisis bargaining. Nonetheless, this literature focuses almost exclusively on signals sent by domestic politics (like audience costs) or negotiating strategies (like screening offers). Formal models rarely examine how military strategies themselves might signal strength. By and large, formal models allow a battle’s informational content to have only two sources: the information revealed from the fact that a state won (or lost) a battle, and the information revealed from its willingness to fight. The actual battlefields and the character of the engagement are taken as given: states choose whether to fight a battle, but not which battles to fight. This simplifying assumption has led theorists to neglect a key source of information during war: the choice of where, when, and how to fight. This article argues that, by studying such decisions, we can understand how some victories become symbolic. Before turning to this argument, though, I first want to suggest two empirical shortcomings with existing work and how a model of symbolic victory might address them.

Most formal treatments of information and war assume two actors with common priors and private information about their relative strength; generally, this private information is asymmetric. These models commonly share two features: (i) a screening process leads weak states to accept bargains early in war and strong states to hold out for better settlements; and (ii) information flows primarily through bargaining (i.e. the offers states make and accept), not through battles themselves. ⁶ We can draw two conclusions from these features.

First, according to this approach, wars should last longer when an opponent is much stronger than expected, because such an opponent will wait to negotiate sincerely. This prediction is difficult to assess empirically. Without a clear definition of strength, we risk post hoc rationalizations in which any losing state is presumed weaker than its adversary (and weaker than it imagined itself ex ante). On the other hand, when studies of asymmetric warfare find that weak states win wars more often than strong ones, this seems equally unsatisfying – clearly our use of words like ‘strong’ and ‘weak’ lacks clarity (Arreguín-Toft, 2001: 97). Nonetheless, even without a rigorous test we should find this prediction implausible. In sports and daily life, the larger the gap between expectations and reality, the faster that gap becomes apparent (usually). The same seems true among nations. If war begins because of a misperception about power or resolve, then the wider the actual gap, the more quickly leaders apprehend it – as in the Gulf War or the Franco-Prussian War.

Second, because information primarily flows from states’ willingness to continue fighting, according to current models the likelihood of war termination should improve with war’s length. This prediction is more testable, and it seems to lack empirical support. For instance, Ramsay (2008) tests a pair of related hypotheses: (i) that as battlefield information (measured in battle-days) increases, so does the probability of war termination; and (ii) that more shocking victories (measured by the difference of expected and actual losses) increase the probability of war termination. He finds no support for either hypothesis: ⁷ shocking victories have some effect, but the variable’s magnitude remains statistically insignificant, while battlefield information, though significant, in fact decreases the probability that war ends. ⁸

The argument in this article sidesteps or resolves these empirical problems. First, it shows why wars might be brief when expectations diverge widely from reality: the greater the divergence, the more incentive to fight highly informative battles. Second, it relocates battlefield information away from length of days or casualty figures, instead emphasizing the political calculus behind strategic decisions. By doing so, it suggests how battles communicating substantial military information, such as unexpectedly large defeats, might be less informative (less symbolic) than battles chosen because of their risk or political significance – because war is primarily about politics, not violence. In short, the argument tries to return our focus to the interplay of politics and military strategy.

Argument and model

I argue an actor can voluntarily diminish its strategic odds of victory in order to signal its strength. It enjoys this opportunity because it can afford more strategic risk than a weak actor, and so it can accept dangers that a weak state would not. As a consequence, either its friends or its enemies (or both) can infer from its strategy that the state is powerful. In short, strategic risk can create the opportunity for a symbolic battle; this symbolic battle conveys substantially more information than a standard engagement.

This argument builds on three premises: that leaders may sometimes choose their battles; that they are uncertain about others’ strength; and that war is costly. The last are standbys in the game theoretic literature on war, but the first is somewhat novel. Formal models tend to treat war as a line, as a set of rails from which the belligerents cannot deviate. In these models, generals have no choice over their battlefields or objectives. ⁹ In effect, these models eliminate military strategy. By introducing one element of military strategy – the choice of how many hazards to accept on a campaign – I show one way military strategy can communicate political information.

This point deserves elaboration. Many bargaining models of war assume a line of N forts (or objectives); when a player captures all the forts, he wins, seizing the pie in full (Smith, 1998; Slantchev, 2003; Smith & Stam, 2004). In each round, players bargain and, if that fails, they fight for the next fort (or, in the most sophisticated models, they do nothing). These models then find, counter-intuitively, that one’s negotiating strategy conveys more information than who wins on the battlefield. However, this finding is not as surprising as it seems. Since all types of player must attack the same target, information only updates through victory, which is highly variable, and negotiating strategies, which are less so. Thus, in this approach, separation between weak and strong types of players will occur mostly in the bargaining phase, not through fighting itself. These battles are weak signals because there is no choice: because both weak and strong states must attack the same targets, in effect these models impose pooling strategies on states. If we allow for choice, permitting states to attack one target rather than another – if we reintroduce military strategy – then battlefield choice regains its symbolism.

A strong state, I suggest, will undertake danger unnecessarily in order to demonstrate its strength. In effect, strong states will sometimes risk defeat more to prove their capabilities than to achieve a military objective.

A few circumstances can make symbolic victories especially useful. If current strategy faces diminishing marginal returns in the information it can communicate, then a symbolic victory may be necessary to correct an opponent’s inaccurate self-assessment. (If military strategy is held constant, players’ beliefs should update on average less and less each battle.) Such a victory is even more advantageous to a strategist pressured by an unstable domestic situation. For instance, during the Mexican–American War, President James Polk expected Mexico to acquiesce to its early territorial losses, but Mexico refused to acknowledge the weakness of its position. Polk then faced two options: he could press gradually southward, continuing Zachary Taylor’s successful campaign; or, he could open a second, riskier campaign against Veracruz (including an unprecedented amphibious landing), culminating in the capture of Mexico City. ¹⁰ He chose the latter, expecting that it would force the Mexican government to accept the reality of its situation, even if the loss of Mexico City could not in itself decide the war. ¹¹

As a general rule, symbolic victories are most useful when an actor’s strength differs substantially from others’ perception of it (see Proposition 2). When facing culturally dissimilar adversaries and target populations, imperial powers employ symbolic battles to highlight the gap in power as quickly and obviously as possible. For instance, the Roman Republic and Empire regularly undertook symbolic demonstrations to convince Germanic tribes of their strength, as these less-developed groups tended to underrate the power of the Roman legions. ¹² The most celebrated of these demonstrations is Caesar’s crossing of the Rhine, a risky military venture which was undertaken for largely symbolic reasons: to demonstrate ‘that Roman armies could and would advance across the river’ (Caesar, 1951: IV.16). In the east, a similar logic may also explain the famous siege of Masada.

While the model will focus on a two-player interaction, symbolic victories also help sway third parties, including domestic audiences and potential allies. Improving morale is one form of such suasion (this will be seen in the study of the Doolittle Raid). Another is political competition over a given population, as in revolutions and insurgencies. Because revolutionaries require a certain amount of popular support, early symbolic victories (like Valmy) help build a movement’s credibility. Similarly, because insurgencies often target the domestic audiences of their antagonists, a symbolic battle can be a more useful bargaining device than military gains.

A common interpretation of the Tet Offensive traces its origins to this strategic logic. Although its initial, defensive approach would gradually erode American and South Vietnamese confidence, the North deliberately adopted a riskier, more aggressive strategy to accelerate this collapse (Summers, 1982: 183–184). By directly challenging prevailing US and South Vietnamese narratives, the offensive would facilitate a speedier end to the conflict. While a tactical failure, the Tet Offensive had its intended strategic effect, decisively reshaping US perceptions of the war.

Modern counter-insurgency has learned the same lesson. Kilcullen, correcting a common misapprehension, writes that ‘winning hearts and minds’ actually refers to a kind of rationalist signaling: ‘“Hearts” means persuading people their best interests are served by your success; “minds” means convincing them that you can protect them, and that resisting you is pointless’ (Kilcullen, 2010: 37). As a consequence, he urges counter-insurgent commanders to seek early victories, which will probably be tactically inconsequential, as a ‘form of armed propaganda’ (Kilcullen, 2010: 38). Because insurgents require popular support, using symbolic victories to change perceptions can be more effective than dramatic combat operations.

For the same reasons, leaders who rely on large coalitions or empires can use symbolic victories to keep partners and neutral states in line. To this end, attacking a particularly dangerous target can communicate to third parties more effectively than attacking the most militarily valuable (or bypassing the threat entirely). Alexander the Great seems to have invoked this logic explicitly in his sieges of Tyre and Gaza: ‘Alexander thought, on the contrary, that the more impracticable it was, the more necessary was the capture; for the achievement would strike great terror into his enemies just because it was beyond calculation.’ ¹³

The Doolittle Raid

A series of Allied setbacks followed the bombing of Pearl Harbor, including the loss of Hong Kong, Singapore, Manila, Guam, and the Dutch East Indies. These setbacks reinforced the intention of President Roosevelt to strike the Japanese mainland. Although such a strike would cause only minimal damage, Roosevelt recognized that it would have an indispensable impact on the American and Japanese psyche. On 18 April 1942, America bombed Tokyo.

The Doolittle Raid is well known, enjoying numerous treatments in popular histories and on the silver screen (all, naturally, of varying accuracy). This fame is unsurprising: its planners intended the raid to excite the American imagination and chill the Japanese; its purpose was not so much to inflict damage as to demonstrate capability. I include it here not to offer an original take on its events but rather because it epitomizes the argument I present. As its details are fairly well established, I hope that a survey of the salient facts will demonstrate the present argument without arousing controversy. Most agree that the highest levels of command, including Franklin Roosevelt, called for the raid in order to boost American morale and demoralize the Japanese; similarly, most scholars agree that it achieved both ends. That is, the US Air Force undertook a great risk for comparatively little military reward and for almost no other purpose than to signal its strength.

The raid was the deliberate policy of Washington. It was not a tactical decision: the assault had its genesis and purpose in the grand strategy of the war. By late December Roosevelt had directed his commanders to plan an attack on the Japanese mainland. The President first approached his Russian allies, whom he hoped would bomb Tokyo for him or, when that tack was rebuffed, at least permit him the use of Vladivostok. The Russians declined, but Roosevelt remained undeterred. In January, he once again pressed his chiefs to devise a way to attack the Japanese mainland, unaware that such plans had progressed steadily since his initial decision. Again and again, Roosevelt emphasized the psychological importance of such a victory (Schultz, 1988: 47), both for Americans distressed by a string of early losses and for Japanese who had not yet tasted serious defeat. ¹⁵ A similar logic echoes among the raid’s architects, Duncan and Low, who both agreed that American soldiers and citizens needed a dramatic victory to improve their morale (Schultz, 1988: 14). So their aims were modest, yet highly significant; they were not trying to force the Japanese to negotiate; they only sought to send a message via a symbolic, psychological victory. ¹⁶ The United States needed to demonstrate its strength, both to its allies and to its enemies, and no better way existed than a risky, flagrant attack on a homeland thought untouchable. ¹⁷

It fulfilled these intentions. Domestically, the attack lifted ebbing American spirits and captured the popular imagination (hence the movie adaptations); internationally, it shattered the confidence of the Japanese people. ¹⁸ It had two primary effects on Japanese strategy. First, it led the Japanese to allocate planes for homeland defense, planes which were desperately needed elsewhere, chiefly in the Solomon Islands (Merrill, 1964: 180). Second, it convinced Japanese leaders of the need to extend their defenses. As many have observed, before the raid Japan focused its efforts to the south; after, they turned east, determined to deny the United States the wherewithal to attack Japan again. The result of these strategic blunders was Midway, the turning point of the Pacific War. ¹⁹

The Doolittle Raid altered the war – and yet, it inflicted almost no damage. Indeed, upon landing Doolittle himself thought that the attack had failed. ²⁰ The tactical futility of the raid has perhaps no better witness than the absence of any intention to repeat it: if its planners had thought it a viable way to inflict material damage, they would have continued bombing; instead, though pleased with its results, no one, including Roosevelt, showed any inclination to replicate the feat (Glines, 1988). Once the raid demonstrated American strength, repeating such a show would serve no purpose. The victory was symbolic.

This symbolism, while meant to communicate with Roosevelt’s Japanese opponents, was aimed even more at the antagonists’ domestic audiences. If morale includes rational expectations of victory, then an easy way to improve morale (or undermine an enemy’s) is to change those expectations. A particularly risky battle, especially a battle only a strong state could undertake and win, can quickly and valuably correct the overconfidence of an opponent or the underconfidence of one’s own people. The Doolittle Raid did both.

The Second Punic War

The Doolittle Raid shows Roosevelt using a risky military venture to signal strength, and in particular to signal strength to the Japanese and American civilian populations. The next case will examine symbolic victories as a tool to signal to allied and neutral states.

In 216 BCE Hannibal Barca achieved the greatest tactical encirclement in the history of warfare. His genius annihilated a Roman force almost twice the size of his own, a defeat that would haunt the Roman psyche for generations. To overstate Hannibal’s tactical achievement would be almost impossible: facing over 80,000 Roman soldiers with perhaps 40,000 of his own, Hannibal set a trap which would kill over 48,000 of his enemy, more than fought in his entire army. ²¹ At Cannae, Carthage inflicted the rising Roman Republic’s bloodiest loss.

In this study, I contrast the battle of Cannae with the siege of Capua. I argue that, although the former exceeds the latter in every measure of tactical military success, the latter, not the former, was more significant to the Second Punic War, because Capua, not Cannae, was a symbolic victory. To advance this argument, I first discuss the antagonists’ strategies; second, I highlight the failure of Cannae to alter the war; third, I discuss the strategic logic for besieging Capua; and finally, I contrast the strategic significance of Capua’s fall with the strategic unimportance of Cannae.

The grand strategies of Rome and Carthage are well documented. Roman strategy passed through three main phases in the Italian theater. First, under Quintus Fabius (appointed dictator), Rome sought to avoid open battle while denying Hannibal the resources necessary to sustain his army in a foreign country. In its second phase, Rome abandoned this strategy to engage the Carthaginians directly, leading to its defeat at Cannae. In its last phase, Roman strategy returned to a Fabian approach, eschewing open confrontation while attempting to confine the damage Hannibal could inflict. Rome recognized it did not need to beat Hannibal to win: so long as Rome maintained control over the larger peninsula, Hannibal could win every battle and yet lose the war.

Carthaginian strategy was equally straightforward. Via a ruthless military campaign, Hannibal intended to induce Rome’s allies to defect. Hannibal recognized that Rome drew its manpower from two sources: the city itself, and Rome’s Italian alliances and possessions. Rome’s defenses meant the city would be difficult to take without a protracted siege, for which Hannibal was unprepared; more importantly, were Hannibal to invest Rome, he would lose the key to his tactical victories, his freedom of maneuver, without which he might not defeat the larger armies Rome could raise. Therefore, Hannibal recognized that his only route to victory was to unravel the Roman alliance system. ²² Indeed, in the early years of the war, Hannibal consistently released prisoners of war who had fought as Rome’s allies, hoping the gestures would peel away Rome’s friends. ²³

Following his victory at Cannae, Hannibal sent an emissary to Rome, expecting his spectacular victory would force the Romans to sue for peace. ²⁴ Rome refused to meet him. Instead, Rome began preparing for a long war. Furthermore, though Hannibal hoped that Rome’s allies would flock to him, most did not: Rome lost the Samnites and some Apulians, but few others. ²⁵ With the exception of Capua, no major city defected after Cannae, and many cities, most prominently Naples, rebuffed Hannibal’s overtures and weathered his assaults rather than betray Rome. Hanno, Hannibal’s domestic rival, summarized the situation like so:

‘But just what is this jubilation all about anyway […] since the battle at Cannae has meant the annihilation of Roman power, and since it is an established fact that all Italy is up in arms, has any people from the Latin league gone over to us? And, secondly, has any individual from the thirty-five Roman tribes deserted to Hannibal?’ When Mago [Hannibal’s ally in Carthage] answered ‘no’ to both questions, Hanno continued […] ‘So we have a war in which we are no further forward than the day Hannibal crossed into Italy.’ (Livy, 2006: XXIII.12–13)

Rome invested Capua as it did most any other city, weakening its defenses through starvation and the gradual collapse of morale. By the close of 212 almost half of Rome’s Italian legions lay encamped about the city, surrounding it with a double line of siege works and their own defensive perimeters. ²⁸ Sensing the blow Capua’s loss would deliver his strategy, Hannibal marched on Rome. Rumors spread claiming that Rome had lost the siege, and citizens panicked in the streets at Hannibal’s approach. Yet the Senate refused to lift the siege of Capua, even at the risk of Rome itself, and finally Rome triumphed. ²⁹ Rome took Capua, drove its aristocrats to suicide, and sold the population into slavery.

The fall of Capua terminated Hannibal’s hopes in Italy. One historian offers this assessment:

Rome persevered and would persist in replacing armies lost […] Symbolically and actually, all of this was epitomized by the wretched fate of Capua […] after Capua’s fall it became clear to all that Hannibal could not watch over widespread allies […] the war was far from over, but its outcome in Italy was all but decided. (O’Connell, 2010: 195–196)

In retrospect, Cannae, a battle whose artistry military officers still study today, determined the outcome of the war far less than Capua, a straightforward siege. The Roman war effort – indeed, the entire Roman international system – depended on its ability to maintain alliances and raise armies from the Italian populace. Cannae did not significantly alter the perception of Rome’s ability to do either, while Capua communicated beyond all doubt Roman strength. Cannae was a great victory, but it was not symbolic. By contrast, Capua was a lesson to all Italian states: Hannibal can win on the battlefield, but he cannot protect his gains; defect and you will be destroyed. Rome undertook the riskiest battle of its Italian campaign as a signal, and that signal secured its victory.

Conclusion

This article opened with the question, why are some battles more significant than others? I have outlined one way a battle can gain an outsized importance: its symbolism. This symbolism, like war itself, is fundamentally political, and as such it speaks to a battle’s importance more than casualty ratios, tactical brilliance, or military value. A battle’s symbolism can come from many sources; one of the most important is its risk. Even small victories can become great symbols if unnecessarily dangerous, bold, or reckless. Capua, for all its banality, settled the war in Italy, while Cannae, for all its brilliance, signified – nothing.

In war, the primary source of information is the campaign, but our informational models of war often omit this source. Different types of states will pursue different paths to victory, and these different paths will signal their strength. In particular, by undertaking unnecessary risk, a state can communicate its strength. If a strong state takes an action which a weak state dare not, it clearly signals its capability. Of course, in actual war, the signals and risk a state can take are rarely so clear. But, while the signals will be mixed, they will exist. Stronger states will more often strive for more difficult, more dangerous objectives, and this tendency will drive at least some separation in assessments of power. I abstract from these complications to capture the essence of the signal, but I would note that in the real world far more signals are being sent than my stylized model would suggest.

Thus far the literature on bargaining during war tends to overlook a crucial signal – military strategy itself. Whether states fight and whether they win are not the only sources of information battles convey: where and how states fight can signify just as much. A symbolic victory can permanently change the strategies and morale of the belligerents, as in the Doolittle Raid. Sometimes, it can even end a war, not because it destroys a general’s enemies, but because it convinces his enemies (and his allies) that he is strong. Symbolism is not the only criterion separating important from unimportant battles, but it is one of them, and one that some of the most celebrated grand strategies have employed.