742 Power or Plenty? not every state possesses.For example,the need to ensure continuing access to the region's oil resources might help explain current American security commit- ments in the Persian Gulf region. Historians of American foreign relations who emphasize the role of economic interests also suggest that the protection of important markets has sometimes led to American security commitments.For example,Hogan (1987,192)argues that the formation of the North Atlantic Treaty Organization was closely linked to efforts to bring about economic recovery in Western Europe and to integrate it into the international economic order American policy makers favored.Similarly, McGlothlen (1993)and Rotter (1987)link American security commitments in Asia to the effort to promote the recovery and integration of Japan.If arguments like these are correct,then part of the apparent effect of alliances on decisions about intervention is actually due to economic interests because these prompted the security commitment in the first place. The potential indirect effect of alliances through trade,and of trade through alliances,makes the magnitude and direction of the trade-alliance relationship important for assessing the effects of economic and security concerns on inter- vention.A single-equation model treating intervention as a function of all these variables together will not capture the indirect effects.A model that considers the potential indirect effects of these variables also suggests a different type of answer to the question of whether economic or security concerns are more important.Instead of emphasizing one or indicating that both influence policy makers in the same way,it holds out the possibility that the two considerations influence different stages of the policy-making process.The next section will present a research design for estimating these effects. Testing the Influence of Economic and Security Interests This section outlines a strategy for testing the role of economic and security con- cerns in various stages of the process leading to intervention.Figure 1 sets out the relationships that will be considered.The first stage of the test is to evaluate the direct effects of economic and security concerns on intervention decisions under certain circumstances.The causal paths of interest in this stage correspond to the arrows pointing to"U.S.Intervention'in the Figure.For the reasons discussed in the last section,concluding the analysis at this point,as previous quantitative analy- ses have done,neglects the important possibility that trade may influence interven- tion by shaping alliances,or vice versa.In order to capture this effect,the next step is to sort out the effects of trade and alliances on one another.Once this has been done,it is possible to estimate the total effect of the independent variables on intervention.The end result is a more realistic test of the relative importance of Economic Interests Rival Intervention U.S.Intervention Alliance commitment FIG.1.Influences on Intervention Decisions
not every state possesses. For example, the need to ensure continuing access to the region’s oil resources might help explain current American security commitments in the Persian Gulf region. Historians of American foreign relations who emphasize the role of economic interests also suggest that the protection of important markets has sometimes led to American security commitments. For example, Hogan (1987, 192) argues that the formation of the North Atlantic Treaty Organization was closely linked to efforts to bring about economic recovery in Western Europe and to integrate it into the international economic order American policy makers favored. Similarly, McGlothlen (1993) and Rotter (1987) link American security commitments in Asia to the effort to promote the recovery and integration of Japan. If arguments like these are correct, then part of the apparent effect of alliances on decisions about intervention is actually due to economic interests because these prompted the security commitment in the first place. The potential indirect effect of alliances through trade, and of trade through alliances, makes the magnitude and direction of the trade-alliance relationship important for assessing the effects of economic and security concerns on intervention. A single-equation model treating intervention as a function of all these variables together will not capture the indirect effects. A model that considers the potential indirect effects of these variables also suggests a different type of answer to the question of whether economic or security concerns are more important. Instead of emphasizing one or indicating that both influence policy makers in the same way, it holds out the possibility that the two considerations influence different stages of the policy-making process. The next section will present a research design for estimating these effects. Testing the Influence of Economic and Security Interests This section outlines a strategy for testing the role of economic and security concerns in various stages of the process leading to intervention. Figure 1 sets out the relationships that will be considered. The first stage of the test is to evaluate the direct effects of economic and security concerns on intervention decisions under certain circumstances. The causal paths of interest in this stage correspond to the arrows pointing to ‘‘U.S. Intervention’’ in the Figure. For the reasons discussed in the last section, concluding the analysis at this point, as previous quantitative analyses have done, neglects the important possibility that trade may influence intervention by shaping alliances, or vice versa. In order to capture this effect, the next step is to sort out the effects of trade and alliances on one another. Once this has been done, it is possible to estimate the total effect of the independent variables on intervention. The end result is a more realistic test of the relative importance of Fig. 1. Influences on Intervention Decisions 742 Power or Plenty?
BENJAMIN O.FORDHAM 743 economic and security concerns on intervention and a more complete account of where each fits into the causal process Testing the effects of economic and security concerns in this way requires solu- tions to two research design problems.First,data on incidents in which Ameri- can intervention was a possibility must be gathered.Because arguments about the role of economic and security concerns apply to many classes of events,I will examine data on both civil wars and international crises.Second,economic and security concerns must be operationalized in realistic ways.I will use data on the behavior of rival states,alliance commitments,and American exports.The remainder of this section will explain these research design choices. Opportunities for Intervention:Civil Wars and International Crises Testing the influence of economic and security concerns on intervention requires data on incidents where intervention was a possibility.In principle, intervention requires no triggering event.States can and do use force without provocation.For research purposes,however,it is useful to begin with a class of events that has sometimes precipitated intervention.Arguments about economic and security interests can then be tested by estimating the influence of observa- ble indicators of these concerns on the probability of intervention within this class of events.I will consider two such classes of events here:civil wars and inter- national crises. Civil wars are a useful setting in which to consider the determinants of inter- vention.Given the potential costs involved,decision makers cannot undertake these interventions lightly.On the other hand,if policy makers believe that con- ditions in the affected states are important,then civil wars are difficult to ignore. Data on civil wars are relatively abundant,but information on intervention in these conflicts is not.Policy makers may decide the stakes in a particular conflict are important,yet use economic or military aid rather than committing their armed forces.The central question here concerns what makes particular civil wars sufficiently important to draw serious American attention,even if they do not involve direct military action.Thus it makes sense to look at intervention more broadly than just the use of force.Unfortunately,military action is the only type of intervention coded in many existing data sets.Patrick Regan's (2000, 2002)data set on civil wars is an exception,containing information about several forms of intervention.Including the provision of economic and military aid,the United States intervened in 38 of the 150 civil wars included in Regan's data, which cover the 1944-99 period. Although interstate conflicts differ from civil wars in many important respects, scholars have made many of the same arguments about economic and security concerns motivating intervention in both.Examining intervention in interna- tional crises complements the analysis of civil war intervention,ensuring that the patterns identified are not unique to that class of conflict events.The Inter- national Crisis Behavior (ICB)project has identified 435 international crises 1A third research design issue concerns the possibility of selection bias in the samples of civil wars and intema- tional crises considered here.Selection bias would be an important issue if American trade or alliance commit- ments influenced the probability that a crisis or civil war broke out in the first place.For example,if credible American alliance commitments always deterred potential challengers from threatening American allies,or per- suaded potential rebels that their cause was hopeless,then crises and civil wars would only be observed when Ameri- can alliance commitments were not credible.The sample of observed crises and civil wars would contain only cases where the American alliance commitment was shaky,perhaps leading to the conclusion that alliance commitments were not strongly associated with subsequent American intervention on behalf of its endangered allies.Although this is an important problem in principle,censored probit selection models designed to handle it turned up little evidence that it made an important difference in practice.The rho parameter was not significantly different from zero,and coefficient estimates were nearly identical to those presented in the next section.A more thorough pre- sentation of these models can be found in the online appendix posted with the replication data
economic and security concerns on intervention and a more complete account of where each fits into the causal process. Testing the effects of economic and security concerns in this way requires solutions to two research design problems. First, data on incidents in which American intervention was a possibility must be gathered. Because arguments about the role of economic and security concerns apply to many classes of events, I will examine data on both civil wars and international crises. Second, economic and security concerns must be operationalized in realistic ways. I will use data on the behavior of rival states, alliance commitments, and American exports. The remainder of this section will explain these research design choices.1 Opportunities for Intervention: Civil Wars and International Crises Testing the influence of economic and security concerns on intervention requires data on incidents where intervention was a possibility. In principle, intervention requires no triggering event. States can and do use force without provocation. For research purposes, however, it is useful to begin with a class of events that has sometimes precipitated intervention. Arguments about economic and security interests can then be tested by estimating the influence of observable indicators of these concerns on the probability of intervention within this class of events. I will consider two such classes of events here: civil wars and international crises. Civil wars are a useful setting in which to consider the determinants of intervention. Given the potential costs involved, decision makers cannot undertake these interventions lightly. On the other hand, if policy makers believe that conditions in the affected states are important, then civil wars are difficult to ignore. Data on civil wars are relatively abundant, but information on intervention in these conflicts is not. Policy makers may decide the stakes in a particular conflict are important, yet use economic or military aid rather than committing their armed forces. The central question here concerns what makes particular civil wars sufficiently important to draw serious American attention, even if they do not involve direct military action. Thus it makes sense to look at intervention more broadly than just the use of force. Unfortunately, military action is the only type of intervention coded in many existing data sets. Patrick Regan’s (2000, 2002) data set on civil wars is an exception, containing information about several forms of intervention. Including the provision of economic and military aid, the United States intervened in 38 of the 150 civil wars included in Regan’s data, which cover the 1944–99 period. Although interstate conflicts differ from civil wars in many important respects, scholars have made many of the same arguments about economic and security concerns motivating intervention in both. Examining intervention in international crises complements the analysis of civil war intervention, ensuring that the patterns identified are not unique to that class of conflict events. The International Crisis Behavior (ICB) project has identified 435 international crises 1 A third research design issue concerns the possibility of selection bias in the samples of civil wars and international crises considered here. Selection bias would be an important issue if American trade or alliance commitments influenced the probability that a crisis or civil war broke out in the first place. For example, if credible American alliance commitments always deterred potential challengers from threatening American allies, or persuaded potential rebels that their cause was hopeless, then crises and civil wars would only be observed when American alliance commitments were not credible. The sample of observed crises and civil wars would contain only cases where the American alliance commitment was shaky, perhaps leading to the conclusion that alliance commitments were not strongly associated with subsequent American intervention on behalf of its endangered allies. Although this is an important problem in principle, censored probit selection models designed to handle it turned up little evidence that it made an important difference in practice. The rho parameter was not significantly different from zero, and coefficient estimates were nearly identical to those presented in the next section. A more thorough presentation of these models can be found in the online appendix posted with the replication data. Benjamin O. Fordham 743
744 Power or Plenty? between 1918 and 2001.2 Brecher and Wilkenfeld (1997,4-5)explain that these events were selected based on two criteria: (1)a change in type and/or an increase in intensity of disruptive,that is,hostile verbal or physical interactions between two or more states,with a heightened probability of military hostilities;that,in turn,(2)destabilizes their relationship and challenges the structure of an international system-global,dominant,or subsystem. Although any crisis could affect American economic or security interests,not all the incidents included in the ICB data are relevant here.In order to test hypotheses about intervention realistically,the events examined must be reason- ably comparable.Decisions about intervention in an ongoing crisis differ from decisions to initiate a crisis in the first place.Bremer (1992),Bennett and Stam (2003),and others treat initiation of wars differently from intervention in ongoing wars for this reason.Although decisions to initiate crises certainly reveal something about intervention,the fact that there are only 20 such cases in the ICB data set limits the analytical usefulness of these events.Only decisions to join ongoing crises will be considered here.Second,some of the crises included in the ICB data occurred during wars.For example,24 crises were part of World War II,14 of them beginning after the United States had become a belligerent. Just as decisions about initiation differ from decisions about intervention,inter- vention in events taking place during wars in which the United States was already a belligerent also differ.These crises are also omitted in the analysis that follows. Finally,crises in which the United States was the target of actions by other states are not appropriate for testing hypotheses about intervention because American leaders were not able to make a decision about their involvement.Overall,393 of the 435 crises that began before 2002 were selected for analysis here. Like Regan's data,the ICB data record major power actions short of direct military intervention.The ICB data include information on economic aid,propa- ganda activity,covert action,and statements by major foreign policy officials.As with civil wars,it makes sense to set the threshold for intervention lower than full-fledged military action,which is likely to be a last resort after less costly policy instruments have failed.For purposes of the analysis presented here,the United States and its rivals were coded as intervening if they undertook some action beyond official statements and propaganda.In terms of the ICB data, intervention included military action,the provision of military advisors,military or economic aid,and covert action.By this standard,the United States inter- vened in 94 of the 393 crises selected for analysis. Operationalizing Economic and Security Interests Because security interests can encompass a wide range of considerations,includ- ing many that are difficult to observe,operationalizing the concept is not easy The analysis here will consider two considerations that have the virtue of being both important and easy to observe.The first is the presence of an alliance with one of the affected states.The security of allies has often been a major concern of American policy makers.For purposes of this analysis,states are considered allies if they have a defensive or offensive alliance with the United States accord- ing to the Alliance Treaty Obligations and Provisions (ATOP)data set (Leeds et al.2002).Civil wars taking place in American allies should be more likely to prompt U.S.intervention.Similarly,international crises in which an American 2 The ICB data include 10 additional crises from 2002 through 2004,but data on the major independent variables used here are not available for these years
between 1918 and 2001.2 Brecher and Wilkenfeld (1997, 4–5) explain that these events were selected based on two criteria: (1) a change in type and ⁄ or an increase in intensity of disruptive, that is, hostile verbal or physical interactions between two or more states, with a heightened probability of military hostilities; that, in turn, (2) destabilizes their relationship and challenges the structure of an international system—global, dominant, or subsystem. Although any crisis could affect American economic or security interests, not all the incidents included in the ICB data are relevant here. In order to test hypotheses about intervention realistically, the events examined must be reasonably comparable. Decisions about intervention in an ongoing crisis differ from decisions to initiate a crisis in the first place. Bremer (1992), Bennett and Stam (2003), and others treat initiation of wars differently from intervention in ongoing wars for this reason. Although decisions to initiate crises certainly reveal something about intervention, the fact that there are only 20 such cases in the ICB data set limits the analytical usefulness of these events. Only decisions to join ongoing crises will be considered here. Second, some of the crises included in the ICB data occurred during wars. For example, 24 crises were part of World War II, 14 of them beginning after the United States had become a belligerent. Just as decisions about initiation differ from decisions about intervention, intervention in events taking place during wars in which the United States was already a belligerent also differ. These crises are also omitted in the analysis that follows. Finally, crises in which the United States was the target of actions by other states are not appropriate for testing hypotheses about intervention because American leaders were not able to make a decision about their involvement. Overall, 393 of the 435 crises that began before 2002 were selected for analysis here. Like Regan’s data, the ICB data record major power actions short of direct military intervention. The ICB data include information on economic aid, propaganda activity, covert action, and statements by major foreign policy officials. As with civil wars, it makes sense to set the threshold for intervention lower than full-fledged military action, which is likely to be a last resort after less costly policy instruments have failed. For purposes of the analysis presented here, the United States and its rivals were coded as intervening if they undertook some action beyond official statements and propaganda. In terms of the ICB data, intervention included military action, the provision of military advisors, military or economic aid, and covert action. By this standard, the United States intervened in 94 of the 393 crises selected for analysis. Operationalizing Economic and Security Interests Because security interests can encompass a wide range of considerations, including many that are difficult to observe, operationalizing the concept is not easy. The analysis here will consider two considerations that have the virtue of being both important and easy to observe. The first is the presence of an alliance with one of the affected states. The security of allies has often been a major concern of American policy makers. For purposes of this analysis, states are considered allies if they have a defensive or offensive alliance with the United States according to the Alliance Treaty Obligations and Provisions (ATOP) data set (Leeds et al. 2002). Civil wars taking place in American allies should be more likely to prompt U.S. intervention. Similarly, international crises in which an American 2 The ICB data include 10 additional crises from 2002 through 2004, but data on the major independent variables used here are not available for these years. 744 Power or Plenty?