Is This a Private Fight or Can Anybody Join?

The Spread of Interstate War

Zachary C. Shirkey

• Publisher: Routledge
• Year: 2016
• ISBN:
  9781317112747
• Edition: 1
• Topic: Politics & International Relations
• Subtopic: Politics
• Index: Politics & International Relations

Some countries join interstate wars well after the war has begun, waiting months and often years, and thus changing their beliefs about the wisdom of entering a war. This volume examines why this might be so, focusing on unforeseen events in wars which cause neutral players to update their expectations about the trajectory of the war, therefore explaining why some wars spread while others do not. The author uses a combination of case studies and statistical analysis to test this theory: the Crimean War, the Franco-Prussian War, World War I, and a study of the spread of war since World War II. Designed for courses on and research into war and other international security issues, this book is a must read.

Chapter 1
The Puzzle of Why States Join Ongoing Wars

We must remember that so long as war exists on the earth there will be some danger that even the nation that most ardently desires peace will be drawn into war

Franklin D. Roosevelt

As Roosevelt’s quotation suggests, national leaders, statesmen, diplomats and political scientists have long been concerned about the spread of war. While rare, the spread of war from one state to another has led to some of the largest, costliest, and deadliest conflicts the world has seen, and therefore, is viewed as a real threat to the state. Wars which significantly altered the international system have almost always involved joining. Both the First and Second World Wars, the Crimean War, and the Korean War all began as bilateral conflicts, but then spread to include other states. Truman feared the Korean War might spread further still. Fear of the spread of war in part led the United States and the Soviet Union to pay attention to and attempt to stop or at least contain several of the Israeli-Egyptian conflicts, though ironically this attention increased the probability the wars would draw in the great powers. Thus, wars often spread to include or threaten states that were initially non-belligerents and even conflicts that remain bilateral are often fought with and influenced by the possibility that other states will join. Indeed, some wars may not be fought at all due to the fact they would draw in additional belligerents. Additionally, the odds an existing war will expand are often greater than the initial odds that a war would occur at all. Finally, the outcomes of wars are altered by joining. For example, the Crimean War and Russo-Turkish War of 1877 had the same initial belligerents and similar causes, yet due to the entries of France and Britain, the former resulted in a Russian defeat, while the later resulted in a Russian victory, though even here Russia had to limit its gains due to the possibility of foreign intervention. Therefore, understanding why and when states join ongoing wars is important, as it is essential to understand how and why wars are initiated, prosecuted, and terminated.

When national leaders speak of the spread of war they often discuss it as though it were driven by some force completely beyond their control, as is exhibited by Roosevelt’s quotation. While this might be convenient for political reasons, it is dissatisfying for the political scientist. To think of states being arbitrarily and almost mystically pulled into wars is unhelpful. Surely there must be some reasons why particular states get drawn into wars, while others remain neutral, and why some wars end up involving many states, while others remain bilateral conflicts. Additionally, the timing of when states join is likely not random and is certainly not determined by the stars. Surely, national leaders must have some sort of control over the spread of war and they should be able to discover, comprehend, and react to, if not necessarily control, the forces that may lead them into war. Leaders make conscious decisions about whether or not to enter a war, rather than being dragged into a war by some sort of mystical force. Events must occur in order to cause these leaders to decide to take their states into war. Given this, political scientists should be able to understand why and when leaders decide to involve their states in wars while others choose to remain neutral and what events or forces lead them to make these decisions. This work will argue that information generated and revealed by wars, such as surprising battlefield results, holds the key to why and when non-belligerents join ongoing wars.1

Previous attempts to understand the spread of war have been largely unsuccessful. Even the terminology has proven difficult. The spread of war has been called infectiousness, diffusion, spillover, and most often, contagion. All of these terms unfortunately connote that the spread of war is some sort of involuntary process, much like the spread of disease from one person to another, while in truth as argued above it is driven by conscious decision-making.2 In order to avoid this misleading connotation, the term “joining” will be used in this work to describe a state voluntarily entering an ongoing war. True, states are sometimes referred to as having joined a war even if they were invaded and became a belligerent involuntarily, but such difficulties of nomenclature are sadly unavoidable.3 Let it suffice to say, that within this work joining will always connote the voluntary entry of a state into a war, unless the phrase “involuntary joining” is used.

Two other terms will be used throughout the work in exactly the same manner as joining for the sake of readability. These are entering and intervening. Entering is a straightforward synonym of joining and requires no explanation. Intervening, however, may be seen as conflating the concept of voluntarily joining a war with humanitarian efforts. The term, intervention, however, has been applied to third parties entering wars since at least the mid 19^th century, while armed mediation was used for what we now commonly call intervention. Intervention has the advantage of conveying the voluntary aspect of entering the war. When confusion is likely, a distinction can always be made between military and humanitarian intervention. Besides, the two concepts are in fact but subsets of the larger concept of third party involvement in a conflict. Thus, intervention or military intervention is a satisfactory term with which to label the action of a state voluntarily joining an ongoing war. Therefore, the terms joining, entering, and intervening will be used synonymously throughout the work.

More troubling than the difficulty of nomenclature has been the literature’s inability to shed light on the causal mechanisms behind joining. Much of the reason for this failure is that previous approaches have focused either on the premise that one war causes additional wars—a proposition for which little evidence has been found—or they have focused on country specific variables in order to explain the geographic spread of war. These country specific approaches, of which much more will be said in Chapter 2, generally try to explain joining through geographic proximity and the alliance structures of states not involved in a war. While such state specific characteristics help partially explain which states get drawn into wars, they offer little insight into which wars are more likely to experience intervention and none into when non-belligerents will enter a war. It seems likely that the key to these unanswered questions resides within the nature of the war itself.4

Napoleon Bonaparte famously said, “War is composed of nothing but surprises.”5 While this is clearly hyperbole, the point is important nevertheless. The outcome and course of a war are difficult to predict. Surprises in war change not only the course of the war, but also the way that non-belligerent states perceive that war. The information revealed by these events holds the key to understanding why and when states join ongoing wars. Information revealed during the course of wars can cause third parties to decide to join those wars and it dictates the timing of their entry.

As will be shown in Chapter 3, revealed information changes the perceived costs and benefits of joining an ongoing war. This is crucial, as any rational change in a state’s decision to enter a war should be driven by a change in that state’s expected utility for joining. Prior to any significant new or revealed information in a war, the expected utility of going to war will generally be the same for a given non-belligerent as it was for that same state at the outbreak of the war.6 Thus, unexpected battlefield results and surprising political events that occur in a belligerent are the key to understanding why and when states will join ongoing wars because these sort of events reveal information during a war and change the expected utility for joining. Unexpected events in particular and revealed information more generally, therefore, should logically dictate the timing of state intervention.

Using revealed information to explain the spread of war is rooted in the wider learning and bargaining theory literature. As was argued above, without the presence of uncertainty and states’ ability to learn from information revealed by wars, there would be little reason for states to join wars well after they had begun. Rather, states would join very quickly or not at all. Thus, this work serves not only as an investigation of intervention, but also as a test of bargaining theory in general. If bargaining theory fails to help illuminate why states become belligerents mid-war, it is unclear why it should help explain the initial outbreak of war. Thus, this work has important implications for the study of war in general and bargaining theory specifically, in addition to its obvious relevance to the literature on the spread of war.

Of course, not all non-belligerents will react to new or revealed information in the same way. Some will be more likely to join than others. First, states that are geographically proximate to the conflict will join at a higher rate than more distant states (Richardson 1960; Siverson and Starr 1991). This is because nearby conflicts will be more salient to states and because geographically proximate states will have a greater ability to join wars since they do not have to project power over great distances in order to intervene. Second, great powers will also join wars at a higher rate than less powerful states (Pearson, Baumann, and Pickering 1994; Wright 1965). This is likely because great powers can project their power more effectively and thus have the ability to influence more wars than do smaller states. Third, alliances should also transmit wars from one ally to another (Siverson and Starr 1991), though this mechanism should operate quite quickly or not at all. Fourth, United Nations involvement should also raise the likelihood of intervention (Betts 1992). Finally, while some information may make joining a war more attractive by revealing opportunities to pick up spoils or a need to balance, other information may make joining the war less attractive. This is because revealed information may indicate defeat is now more likely if the state joins or that a potential enemy that was earlier perceived to be a growing threat has been sufficiently contained and there is, therefore, less of a need to balance against it. These causes and correlates of intervention will be derived and fleshed out in the next chapter.

The body of the work is laid out in the following manner. In Chapter 2, a new theory of joining is laid out, but first the existing state of the joining literature is discussed. Specifically, the three main theoretical approaches to understanding why states join wars, Siverson and Starr’s (1991) “opportunity and willingness” framework, Haldi’s (2003) political costs approach, and Altfeld and Bueno de Mesquita’s (1979) rational actor model will be presented and their strengths and flaws examined. All three approaches have strengths, but ultimately fall short. Siverson and Starr’s approach is able to show that states with allies in a conflict and geographically proximate states are more likely to join an ongoing war. These findings are helpful, but they do not explain the underlying question of why states join, nor when they join. Geography and often alliance structures remain constant throughout a conflict, yet states often do not intervene initially. What causes this change in behavior? Haldi’s approach offers that states join when political costs are low and they remain neutral when costs are high. This approaches tautology and Haldi does not develop the concept further. The only variation Haldi finds in political costs is that prior to the Napoleonic wars they were low and afterward they were high. While this may be true, it means that the theory provides absolutely no indication about which states are more likely to join and in which wars states are more likely to intervene since 1815. Obviously, this is dissatisfying, as the level of intervention has varied since 1815. Finally, Altfeld and Bueno de Mesquita focus on the fact that joiners can alter the probability of which side will win a war and to a lesser extent on the reputational benefit that accrues to states that honor their alliances. Altfeld and Bueno de Mesquita argue that states will join in order to increase the odds their preferred outcome for the war will occur and that states will be careful to avoid joining the losing side as to avoid bearing unnecessary costs. While these factors are undoubtedly very important to understanding joining, Altfeld and Bueno de Mesquita look at joining only in the first two months of a war and do not attempt to explain when states join wars. As this work’s focus is late joining and the timing of joining, it can help answer questions that are not addressed by Altfeld and Bueno de Mesquita.

After Chapter 2 illustrates that despite their strengths existing explanations are ultimately insufficient, the chapter develops a new theory of military intervention. The goal of this new theory is to explain which states will intervene, which wars are most likely to grow in size, and most especially when states will join. It builds upon the concepts of revealed information and unexpected events and is based chiefly upon the works of Blainey, Goemans, Iklé, Wagner, and Wittman. Specifically, the theory argues that something in the war itself must change in order for a non-belligerent to decide to join. This is because if conditions had remained constant, the non-belligerent would have stuck with its initial decision to remain neutral. Non-belligerents incorporate the information revealed by events in the war into their calculations about the benefits of entering the war. These changes are what explain when states join and why certain wars experience intervention while others do not. Obviously, this framework is not applicable to states that join very soon after a war begins, as such delays may be due to mechanical aspects of declaring war or waiting for news of the outbreak of hostilities rather than uncertainty about whether belligerency is wise given the occurrence of the war.

In Chapter 3, the theory advanced in Chapter 2 is tested using a large statistical study. All interstate wars in the Correlates of War (COW) database from 1816-1995 are included. Additionally, two more recent interstate wars were included: Kargil and Eritrea-Ethiopia. This results in only two interstate wars since 1815 not being included: US-Afghanistan and US-Iraq. Both wars are ongoing and while they clearly began as interstate wars, have both morphed into civil wars.7 Additionally, while both wars are multilateral, states not among the initial belligerents have yet to involve themselves in either war to a sufficient degree to warrant labeling the action joining, though there is an outside possibility that bordering states’ actions may eventually escalate to such a level.8 Whether states voluntarily joined an ongoing war—as opposed to being attacked by a belligerent—is regressed against variables derived from previous approaches and the hypotheses advanced in Chapter 2. Tests are run to see if unexpected events can predict when states enter wars and also when they leave. The tests use generalized estimating equations (GEEs). GEEs, a subset of generalized linear models, are better able to control for temporal effects in models involving lagged variables than are the more common maximum likelihood estimation (MLE) models.9 The interpretation of GEE coefficients is identical to the interpretation of MLE, so the results can be easily understood by anyone familiar with logistic regression techniques.10

Extra-systemic wars were excluded from the study because state intervention almos...

Table of contents

• Cover Page
• Dedication
• Title Page
• Copyright Page
• Contents
• List of Tables and Figure
• Acknowledgements
• List of Abbreviations
• 1 The Puzzle of Why States Join Ongoing Wars
• 2 Previous Findings and a New Theory of Joining
• 3 Statistical Analysis of the Spread of War
• 4 The Crimean War: Public Opinion, Divided Cabinets, and the Partial Spread of War
• 5 The First World War: The Growth of a World War
• 6 The Franco-Prussian War: The War that Refused to Grow
• 7 Joining Since 1945: Balancing, Bandwagoning, and the Changing Nature of Spoils
• 8 Conclusions, Extensions, and Avenues for Future Research
• Appendix: Coding for Unexpected Events, Regions, and Contiguity
• Bibliography
• Index