Multiparty Disputes and the Probability of War: 1816-1992
Revisions Submitted to Conflict Management and Peace Science
19 March 2004
Karen K. Petersen, Vanderbilt University; John A. Vasquez, Colgate University;
and Yijia Wang, Vanderbilt University
1
MULTIPARTY DISPUTES AND THE PROBABILITY OF WAR: 1816-1992
Abstract
Previous theory and research have suggested that multiparty disputes might be
significantly more likely to escalate to war than bilateral disputes, because of the
difficulty of reaching a mutually acceptable agreement as the number of parties increases.
This study presents a systematic test of this hypothesis. Efforts to provide such a test have
been hampered by the absence of data that distinguish the number of participants in a
militarized interstate dispute prior to the outbreak of war from the number of participants
after the war breaks out. We find that multiparty disputes do have an increased
probability to escalate to war. In addition, we find that the issue over which the disputants
contend has an important effect on the probability that the dispute will escalate to war,
regardless of whether the dispute involves multiple participants or is simply a bilateral
dispute. In order to contribute to future scholarship on this topic, the data for the new
classification scheme of multiparty disputes are published in the Appendix.
2
INTRODUCTION
Among the most important legacies of Stuart Bremer were his completion of the
Militarized Interstate Dispute (MID2.1) data set and the theoretical and methodological
changes he helped bring about in light of the possibilities created by these data. His work
on MIDs resulted in two key shifts in the intellectual history of peace research. The first
was the shift from systemic analyses of why war occurs to an emphasis on what
distinguishes militarized disputes that escalate to war from those that do not. The second
was the shift from the correlates of war to what factors increase the probability of war.
Each of these shifts has made research within the field much more successful and
cumulative than it was before Bremer’s work.
What distinguishes MIDs that escalate to war from those that do not has been a
new theoretical approach within international relations research, and it has given rise to a
new research program centered on a particular way of conceptualizing how war arises.
Much of the theoretical edifice for this approach was first laid out in Bremer and Cusack
(1995), which set out several stages or sequences that depicted the various factors that
might affect the process by which war might emerge. The mere fact of looking at war as a
process that might emerge from the interaction of states was in itself somewhat
revolutionary, given the systemic emphasis of the previous two decades.
If we think about the factors that might distinguish MIDs that escalate to war from
those that do not, we can see that there are four obvious sets of characteristics that should
be examined: first, the attributes of the MID itself—e.g. the kind of issue under
contention, such as territory; second, the characteristics of the actors in the disputes, e.g.
whether they are neighbors or democracies; third, what these states actually do to each
3
other, e.g. the nature of their bargaining and the history of their prior interactions; and
lastly, the systemic context in which the MID occurs, e.g. whether the norms of the
system are restrictive or permissive (see Raymond 2000).
Much of the research associated with the second set of variables has been framed
in terms of dyadic analyses, and here again Bremer (1992) led the way by looking at the
attributes that would distinguish the dangerous dyads from the ones that would be less
likely to go to war or in some cases “never” or rarely go to war. Of course, some of the
variables used in his analysis of dangerous dyads actually included factors that reflected
behavior that states had previously taken and not just static attributes—these would
include variables like whether states were allied to each other or militarized, and in
Bremer (2000) whether they had a history of militarized confrontations.
The dyadic analyses brought about by Bremer’s (1992) work have resulted in a
major research design breakthrough for peace science in that they have produced a
number of important findings, best illustrated by the work on the democratic peace, but
also by the work on rivalry (Diehl and Goertz 2000) and on territorial disputes (Hensel
1996; Vasquez and Henehan 2001; Senese and Vasquez 2003). The extensive popularity
of dyadic analyses, however, has diverted attention away from characteristics of MIDs
that may increase the probability of war that are associated with the dispute itself and not
the dyad. In particular, researchers have tended not to think about the various specific
characteristics of disputes that might account for its escalation to war. Perhaps the
variable that has been most forgotten by dyadic analyses is the number of actors involved
in a dispute; i.e. whether an MID involves multiple parties. This is the subject of this
study.
4
Previous research, particularly that of Cusack and Eberwein (1982) on a
forerunner of the MID data, has found a significant relationship between multiparty
disputes and the onset of war. Analyzing the relationship between multiparty disputes and
the probability of war, however, is not easily done with the current MID data, primarily
because no distinction has been made in the data as to whether the MID becomes
multiparty before or after the onset of war.
In what is regarded by most as a seminal article in the scientific study of
international conflict, Stuart Bremer commented on a data limitation that we correct
herein. When laying out the research design for Dangerous Dyads he claimed:
If all wars began as one-on-one confrontations, then for each of the 56
interstate wars that began during the period under study there would be
one dyad of original participants, but the historical record as not quite so
simple. In 13 of the 56 qualifying wars, two or more states became
involved in war with one or more other state on the very first day of the
war. These may be instances of genuine collusion or very fast joining
behavior (I favor the former interpretation), but unfortunately the available
historical record does not allow us to distinguish reliably between the two.
(Bremer 1992, 321)
We do, in fact, believe that distinguishing between collusion and joining is both
empirically important and feasible. In our discussion herein dealing with multiparty
disputes, collusion refers to instances when three or more states are party to a dispute that
leads to war; whereas joining refers to instances when two states go to war and are
subsequently joined by one or more additional states.
5
Distinguishing between collusion and joining is important because previous
studies have attempted to distinguish between bilateral and multiparty dispute escalation
without explicitly discussing the distinction. Cusack and Eberwien (1982: 25) found
evidence that the expansion of disputes makes war more likely and conclude that “the
entrance of third parties into ongoing serious international disputes has been associated
with the escalation of such disputes to war.” Gochman and Maoz analyze Militarized
Interstate Disputes (MIDs) from 1816 to 1976 and find that 22 percent of the multiparty
disputes escalated to war compared to 5 percent of the dyadic disputes (1984: 602). They
posit several reasons for the war-proneness of multiparty disputes. First, they claim that
the larger aggregate of capabilities makes the sustenance of full-scale conflict possible.
Second, major states tend to intervene more, and major states have greater capacity to
sustain hostilities. Finally, they claim that “the decision- making dynamics of multiparty
disputes may make it difficult to control the escalatory potential of conflict spirals” (602).
Likewise, Vasquez (1993: 190-193) argues that the size of a dispute affects its probability
of war because it is more difficult to negotiate among several parties than one and that
outcomes from multiparty disputes are more apt to leave one or more parties less satisfied
than a bilateral negotiation would. Nonetheless, the empirical evidence discussed above
is based on incomplete information. This is so because of the restrictions of the current
MID data; it is not possible to make valid claims about the escalation of multiparty
disputes because joining and collusion are indistinguishable.
The crisis literature also addresses the issue of multiple partic ipants. In his work
on international crises, Brecher (1993) finds that “the larger the number of parties in a
bargaining sequence, the more difficult it is to attain a solution that will satisfy all
6
concerned. Under such circumstances, there is reason to expect that one or more actors
will resort to violence in the escalation phase” (151). Brecher also finds that crises of
short duration are more likely to involve only two participants (245) and that crises with
multiple actors are more intense and more likely to have a high impact (331).
Additionally, Brecher and Wilkenfeld (1997) find that crises with multiple actors are
significantly more likely to experience intervention by global organizations than crises
with only two actors (858). Likewise, Jame s and Wilkenfeld (1984) find that crises that
involve three or more parties tend to be longer and have outcomes that are less
satisfactory because the bargaining dynamics are more complicated.
While the ICB crisis data is not directly comparable to the MID data, it is
encouraging that the findings from the crisis data indicate that there is in fact a difference
between bilateral and multiparty disputes/crises. However, within the MID data there is
not an explicit distinction between original participants and joiners to the ensuing war (or
collusion and joining). Given the existing coding rules, it is not possible to tell whether
all the actors enter the MID before or after the MID escalates to war. Since it is clear that
a distinction should be made between bilateral and multiparty disputes, we posit that it is
important that multiparty disputes be properly classified so as to be able to clearly and
confidently state the effect that multiple participants have on escalation.
THEORY
The conflict literature contains some discussion of the difficulty of conflict
resolution when multiple parties are involved in a dispute. Both Gochman and Maoz
(1984) and Brecher (1993) briefly address the issue of conflict resolution and how
multiple participants might make resolution more difficult. Additionally, in her study of
7
the impact of alliances on conflict behavior, Leeds notes that “… it is reasonable to
assume that all else equal, increasing the number of parties that must be satisfied by a
bargain to avoid war makes the negotiation of a successful settlement less likely, and war
correspondingly more likely” (2003: 8). i Negotiations in situations of militarized
conflict, whether mediated through a third party or resolved among the participants to the
dispute, require consideration of the issues underlying the dispute in order to understand
the nature of the escalation to or termination short of war. ii It then follows that the more
participants the less similarity of interests and, perhaps more important, settlement
potential will also vary depending on the issue(s) at stake.
The inability to reach negotiated settlements inevitably leads to prolonged and
protracted conflicts that produce more battle casualties and become “wars” under the
Correlates of War operational definition of war. According to Leeds, “escalation to war
and longer more costly wars are a result of particularly intractable bargaining problems
(Wagner 2000, Filson and Werner 2002, Smith and Stam n.d.)” (2003: 5).
With the
increase in the number of parties in a negotiation, the likelihood of reaching a unanimous
agreement will also be correspondingly diminished, leading to conflict escalation. This
“intransigence factor” may help explain why the "size factor" facilitates the escalation of
militarized disputes to all-out wars. Based on the “intransigence factor,” the international
conflict literature, and the business dispute resolution literature, we develop an issuebased explanation for the war-proneness of multiparty disputes.
Issue space is an important component of our theory of the war-proneness of
multiparty disputes. Previous research has focused on the role of issues in militarized
conflict, but not jointly on the role of the size of the dispute (or number of participants)
8
and the issue at stake. For example, Vasquez (1993) lays out the theoretical foundation
for an analysis of conflict through the lens of an issue-based paradigm (see also
Mansbach and Vasquez 1981); and Holsti (1991) examines armed conflicts from 1648 to
1989 using an issue-based approach. Issues are important because the common ground
available to participants may vary by issue type. Some issues may be easier to resolve
simply because states may be more willing to compromise over an issue that does not
threaten their existence, for example.
If issues matter, then the resolution of a dispute prior to the outbreak of war
requires that the participants find some common ground that will satisfy (or at least
“satisfice”) the participants. iii The reduction in common ground, or more technically the
reduction in overlapping issue positions, means that what would have been acceptable to
the two parties might not be acceptable to additional parties, which thereby reduces the
number of acceptable proposals. In this manner, proposals that would resolve the issue
are reduced to the least common denominator, especially since any party to the dispute
can often exercise an informal veto over settlement. In multiparty disputes, all are held
hostage to the actor that is most intransigent or least able to sign an agreement, so long as
all seek to remain within this coalition. Therefore, disputes involving more than two
states will be less likely to be resolved prior to the escalation to war (if in fact the
addition of third parties reduces the common ground) and thus more likely to lead to war
than disputes between two parties.
Two historical examples show that such a dynamic can be at play in the real
world. Both of these examples are cases involving actors that are willing to settle, but do
not because of the issue positions of their coalition partners. So they end up going to
9
war. In the events leading up to the Crimean War, for instance, Napoleon III of France,
initiated the crisis by placing demands on the Sultan of the Ottoman Empire that he be
granted certain rights to protect Christians of the Latin rite. This in turn raised the ire of
the Russian Tsar. Britain was brought into the crisis because it is aligned with France.
Later, when Napoleon III was willing to settle because his basic demands were met, he
does not because Britain is unwilling to settle, and he ends up going to war (see
Richardson 1994: Ch. 5).
Similarly, during the negotiations between Japan and the U.S. in the fall of 1941,
Franklin D. Roosevelt developed a modus vivendi proposal that would have loosened the
oil embargo placed on Japan in return for partial withdrawal of Japanese troops from
Indochina. Churchill and Chiang Kai-shek objected and the proposal was never offered
(Iriye 1987: 180-81) with the attack on Pearl Harbor being the result. Here, we have an
example of a proposal that FDR thought would have delayed war (and it probably would
have (Richardson 1994: 190)) being put aside, in part because of objections of other
members of the coalition.
Another factor that makes it more difficult to resolve multiparty disputes is that,
with intractable issues, it is often necessary to frame the issue in a radically different way
to reach a mutually satisfactory agreement (see Burton 1990; Kriesberg 2003). Such reframing, especially of intractable issues, is required to move actors from zero-sum
proposals to win- win proposals, or as Figure 1 shows, from the quadrant with the
distribution of proposed costs and benefits that is unequal to the quadrant where the
distribution is equal. Getting two actors to do this is difficult enough; getting three or
five to do it is obviously a more arduous task, especially since each actor may have
10
slightly different "interests" at stake and, more importantly, different domestic
constituencies (or audiences) that may prohibit it from signing on to certain classes of
proposals (see Roy 1997).
(Figure 1 about here)
All of these factors lead us to believe that multiparty disputes, ceteris paribus,
will be more difficult to resolve than dyadic disputes. Disputes that are difficult to
resolve tend to repeat if they are salient (both in terms of their importance to decision
makers and public awareness of the issue). Empirical research has sho wn that disputes
that recur have a higher probability of going to war (Hensel 1994). Therefore, if
multiparty disputes are intrinsically more difficult to resolve and if they are salient, and
therefore recur, it follows that they should have a higher probability of escalating to war
than dyadic disputes.
It follows from the above that while multiparty disputes may be generally more
difficult to resolve, the key to whether they will escalate to war depends on their salience.
Salience also impacts their tendency to recur, thus making resolution even less likely.
The territorial explanation of war (Vasquez 1993: Ch. 4) maintains that territorial issues
are potentially the most salient and most likely to go to war; and indeed, a growing body
of empirical work has found militarized disputes over territory to be the most war prone
disputes (Ben-Yehuda 1997, 2000; Hensel 1996; Huth 1996; Senese 1996; Vasquez and
Henehan 2001; Senese and Vasquez 2003). Vasquez (1993: Ch. 4) sees territorial issues
as an important underlying cause of war rather than a proximate cause of war because
they do not directly “cause” war but rather set off a train of events that can culminate in
war. Whether they do or not depends on how they are handled. If they are handled
11
through the use of power politics, then the probability of war increases greatly. Power
politics is seen as the more proximate "cause" of war (see also Vasquez and Hene han
2001: 123).
In addition, Hensel (1994) shows that territorial disputes are apt to recur, and the
rivalry literature shows that recurring disputes are associated with having wars (Diehl and
Goertz 2000). Given these findings, while we would expect multiparty disputes in
general to escalate to war, we would expect multiparty territorial disputes to be
particularly prone to war.
In summary, we have presented a theoretical rationale for the war-proneness of
multiparty disputes, and based on that, we examine the effect of a contentious issue
(territory) when multiple parties are present with the propensity for dispute escalation.
Any one of those factors alone should increase the probability of war, but disputes that
combine territoria l issues and multiple parties should be especially prone to escalation.
In order to test our positions, we created a rigorous system for classifying disputes as
bilateral or multiparty thereby contributing to the existing MID data set. It is our
contention that other analyses of the war-proneness of multiparty disputes are less than
optimal in that they do not distinguish between joining and genuine collusion. Our
analysis improves upon previous work by incorporating more rigorous criteria for the
classification of multiparty wars and by incorporating the role of issues into an analysis
of the probability that a militarized dispute will escalate to war.
12
RESEARCH DESIGN
We are basing our analyses on theoretical premises that claim that multiple parties
involved in a dispute make dispute resolution less likely and that territorial disputes are
more prone to escalation. Therefore, proposition 1 states:
1) Disputes with multiple participants will escalate to war more frequently
than expected by chance.
If multiparty disputes are as difficult to resolve as we suspect, then it would be expected
that multiparty disputes escalate to war more frequently than bilateral disputes as well as
more frequently than would be expected by chance. Therefore, proposition 2 states:
2) Disputes with multiple participant are more likely to escalate to war
than are disputes between only two parties.
Additionally, if disputes over territory are more war prone in general, then
multiparty disputes that involve territory should be more war prone than multiparty
disputes over other issues. Therefore, proposition 3 states:
3) Multiparty disputes that involve issues of territory are more likely to
escalate than multiparty disputes over other issues.
Our propositions necessitate the use of the MID as the unit of analysis. Therefore,
there is one observation per militarized dispute iv ; and the temporal domain is 1816
through 1992 for which we employ the Militarized Interstate Dispute Data and the
Correlates of War Interstate War Data (see Jones et al. 1996 for MID coding information,
and Singer and Small 1982, for more information on the COW Interstate War data).
Dispute size refers to the number of participants (nation-states) in a MID. A war is a
MID that involves a total of 1,000 or more battle fatalities across all of the participants
13
(Small and Singer 1982: 55). To be considered a war participant, a state must either
suffer a minimum of 100 fatalities or commit at least 1,000 troops to the effort.
The main problem in testing our propositions is that the MID data do not contain
a variable representing the dispute size as discussed above; therefore, we created the
variable by comparing the start dates for MIDs with multiple participants that escalate to
war with the start dates for these wars in the COW Interstate War data set. v MIDs with
more than two participants that escalate to war are problematic because the data do not
distinguish whether the participants joined before or after the MID escalated to war. In
order to classify MIDs as multiparty or bilateral, the date of entry in the MID and the date
that the war began (according to the COW Interstate War Data) for all of the MIDs that
escalated to a hostility level of 5 (war) and contained more than two participants were
examined. If there were more than two participants in the MID on or before the day that
war broke out, then the MID is coded as multipartyvi. If only two of the participants were
actually party to the MID prior to the outbreak of war, then the MID is coded as
bilateralvii. All MIDs that did not escalate to war, but contained more than two
participants are coded as multiparty. Given these coding rules, about 16% of all MIDs
are multiparty MIDs. Of these 16%, about 12% escalate to war as opposed to roughly
4% of the bilateral MIDs. viii
The primary problem with classifying disputes that have multiple parties without
considering when participants join is that it may conflate war joining and war initiation.
If start dates are not taken into consideration and all multiparty wars are included
regardless of whether the participants were party to the MID prior to the outbreak of war,
then about 15% of multiparty disputes escalate to war—more than our findings indicate. ix
14
In addition to the size of the dispute, the issue at stake is also analyzed. The issue
is determined based on the MID code for revision type. The revision type represents the
goal of the state(s) attempting to alter the status quo and can take on four possible values:
territory, regime, policy, and other. All disputes require an explicit claim of some type in
order to classify the revision type. For example, in order to be coded as a territorial
dispute, the revisionist actor must make explicit a claim to some or all of the territory of
the target state prior to the onset of an MID (see Jones et al. 1996: 178 for complete
coding rules).
Because the MID is the unit is analysis, many of the standard control variables
commonly used in the conflict literature cannot be feasibly employed herein. For
example, contiguity is a dyadic measure and many of the disputes have three or more
participants. The presence or absence of democracy is not something that can be
measured for particular disputes, but is instead a measure applied to states or pairs of
states. Using capabilities as control variable follows the same logic. Therefore, only
variables relevant to disputes as a unit of analysis are used in the analyses below.
In the following section, we begin with a bivariate analysis of the relationship
between dispute size and war, followed by multivariate logistic regression analysis of the
same relationship. After establishing the importance of dispute size, we then evaluate the
impact of the issue at stake in the dispute as well.
FINDINGS
We test Proposition 1 by comparing the probability that bilateral and multiparty
disputes will escalate to war with the base probability that any given dispute will escalate
to war. Table 1 reports the findings of our analysis of Proposition 1.
15
(Table 1 about here)
Table 1 clearly demonstrates that multiparty disputes have a higher probability of
going to war than expected by chance. Multiparty disputes have more than twice as
many observed instances of war than would be expected. In the case of multiparty
disputes, the conditional probability is 0.12, compared to an overall base probability of
0.0547; and the Z-score x of 4.850 is statistically significant at the .001 level, indicating
that there is a statistically significant difference in the conditional and base probability of
war for multiparty disputes. Conversely, bilateral disputes have a conditional probability
of war that is less than the base probability (.042) and thus less observed wars than
expected. The Z-score for bilateral disputes is negative and statistically significant at the
.05 level, indicating that bilateral disputes are less likely to escalate to war than expected
by chance.
Proposition 2 is evaluated by comparing the conditional probability of war for the
two types of disputes. The conditional probability of war for multiparty disputes is about
three times greater than the conditional probability of war for bilateral disputes (0.12
versus 0.04, respectively). Only 59 of 1403 bilateral disputes go to war, whereas 32 of
260 multiparty disputes go to war. Therefore, multiparty disputes are significantly more
likely to escalate to war than bilateral disputes. We find considerable support for both
Proposition 1 and Proposition 2 on the basis of the results presented in Table 1.
Proposition 3 compares the probability that disputes with multiple participants
will escalate to war by the type of issue at stake. Proposition 3 is tested by comparing the
conditional probabilities of war in disputes with multiple participants across issue type.
The results are presented in Table 2 below.
16
(Table 2 about here)
Proposition 3 claims that multiparty disputes should similarly be affected by issue
type, and the results in Table 2 support Proposition 3. Only disputes over territorial
issues have a higher conditional probability relative to the base probability (.243 versus
.123, respectively). The difference in the conditional and base probability is statistically
significant at the .001 level. Policy disputes have a lower conditional probability (.082),
and that difference barely misses statistical significance at the .05 level. Comparing the
conditional probabilities across categories reveals that multiparty territorial disputes are
more than three times more likely to escalate to war than multiparty policy disputes or
multiparty regime disputes and more than twice as likely to escalate to war than
multiparty “other” disputes xi. It should also be kept in mind that neither the regime nor
the “other” disputes reach statistical significance.
In addition to a comparison of the conditional and base probabilities, the results
from a logistic regression analysis of the effect of multiple participants and issue types on
the probability of war are reported in Table 3 below. Estimating a logit model is
necessary due to the dichotomous nature of the dependent variable. The reported
coefficients are not exponentiated; however, the percentage change in odds are reported.
(Table 3 about here)
When compared to policy disputes xii, territorial disputes are significantly more
likely to lead to war. In fact, the log odds ratio increases by 207%, indicating that the
odds of a territorial dispute escalating are more than 200% greater than the odds of a
policy dispute escalating. Multiparty disputes are more likely to escalate to war than
bilateral disputes, with a percentage change in odds of 232%, even when controlling for
17
issue type. Again, this change in the odds ratio indicates that multiparty disputes are
more than 200% more likely to escalate to war than are bilateral disputes. Regime
disputes are not statistically significantly different from policy disputes in their escalation
propensity. “Other” disputes, while statistically significantly different from policy
disputes only account for 1 of the 31 multiparty wars (one should also keep in mind the
coding issues related to “other”--see note ix).
One interesting way to analyze the results of regression analysis is to look at
simulated probabilities. Table 4 lists the simulated probability of war under different
conditions generated using CLARIFY (King et al. 2000). xiii
(Table 4 about here)
The base probability of war from Tables 1 and 2 above is about 5% overall and 12% for
multiparty disputes. The simulated probability of escalation to war for a territorial
dispute with multiple participants is 20%, four times higher than the overall probability
and almost twice as high as the probability of escalation for multiparty disputes as a
whole. Bilateral disputes over territory are more than three times as likely to escalate to
war then bilateral disputes over policy (.07 versus .02, respectively), and multilateral
disputes over territory are almost three times more likely to escalate to war than
multiparty disputes over policy issues (.20 and .08, respectively), which supports
Proposition 3. xiv
CONCLUSIONS
We set out to correct the limitations of the MID data when it comes to analyzing
multiparty dispute escalation and then empirically confirm what has come to be known as
“conventional wisdom” in international conflict studies. We were able to create a
18
measure of multiparty dispute escalation that distinguishes between war joining and
collusion and we did confirm that multiparty disputes do escalate to war more frequently
than bilateral disputes. However, the rate of escalation is less than previous studies
indicated—a disparity that could have an impact on analyses of interstate conflict.
In the process of correcting the above problem, we set out to explain why
multiparty disputes might be more likely escalate and what role the issue at stake in a
dispute might play in the propensity for these disputes to escalate. A set of propositions
about the relationship between escalation and the number of partic ipants and the issue at
stake followed naturally from our discussion. The findings presented in Table 1 above
support our contention that disputes that involve more than two parties are more difficult
to resolve short of war. The common ground available to disputants probably shrinks
drastically with the addition of each participant, making war more likely as opposed to
conflict resolution. Additionally, as Tables 2 through 4 show, disputes over territory are
more likely to escalate to war than disputes over other issues, even in the context of a
multiparty dispute, which supports our propositions that the issue type at stake should
impact the probability of escalation to war for multiparty disputes.
It is likely that dispute escalation is not the only phase that is affected by the
presence of multiple parties. The resolution of disputes is probably very different when
there are multiple parties involved. Thus, our findings suggest that more attention should
be given to the study of conflict resolution with particular attention to methods for
successfully dealing with multiple participants and the issues over which they contend.
Increasing the common ground may not be the only option available.
19
As we mentioned at the outset, the territorial explanation of war centers on
territory as a predisposing cause of war. The more proximate cause may be the way in
which territorial disputes are handled. If such disputes are being handled in a power
politics fashion, then this may be the driving force behind escalation. The hostile spiral
that often develops out of such behavior should be expected to be exacerbated when there
are more than two participants involved; thus, exploring conflict management techniques
that reduce the propensity to employ power politics techniques could go a long way
towards ameliorating the most dangerous types of disputes. When combined with
methods for softening issue positions and increasing the common ground available to
disputants, a reduction in power politics behavior could ha ve an impact on the occurrence
of dispute escalation.
20
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24
25
Appendix A: Multiparty MIDs that Escalate to Warxv
Appendix A contains a list of the wars with multiple participants in the MID prior to the
outbreak of war. The following information is presented: the MID ID number, the name
of the war from the COW War Data, the names of all participants in the MID (those who
reach level 5 hostility are in bold), the revision type of the MID, and the multiparty
status. Multiparty status indicates whether there were multiple participants in the MID
one, three, and five (1, 3, 5) days prior to the outbreak of war.
MID ID
Number
COW War Name
19
Austro-Sardinian
31
Boxer Rebellion
57
Crimean War
88
Franco-Prussian War
89
Franco-Spanish War
111
112
135
Italo-Ethiopian War
Italo-Roman War
Wars of Italian
Unification
Franco-Mexican War
175
Roman Republic
180
Russo-Japanese War
194
Second SchleswigHolstein War
196
Franco- Thai War
200
Sinai War
115
MID Participants
Italy, Tuscany, Modena, AustriaHungary
Japan, France, U.K., Russia,
China, U.S., Austria-Hungary, Italy,
Germany
France, Russia, Italy, U.K.,
Turkey/Ottoman Empire, AustriaHungary
Germany/Prussia, France, Bavaria,
Wuerttemburg, Baden
Spain, France, Austria-Hungary,
Germany, Russia
Italy, Ethiopia, U.K.
Papal States, Italy, France
Italy, Austria-Hungary, France,
Germany
Mexico, France, U.K., Spain
Austria-Hungary, Papal States,
France, Two Sicilies
Japan, Russia, Korea
Germany, Denmark, U.K., AustriaHungary, Saxony, Wuerttemburg,
Hesse Grand Ducal, Baden, Hanover
France, Thailand, U.K.
Egypt, France, Israel, U.K., U.S.,
U.S.S.R
MID
Revision
Type
Multiparty
Status
Territory
1,3,5
Policy
1,3,5
Policy
1,3,5
Other
1,3
Policy
1,3,5
Territory
Territory
1,3,5
1
Territory
1,3,5
Regime
1,3,5
Policy
1,3,5
Territory
1,3,5
Territory
1,3,5
Territory
1,3,5
Policy
1,3,5
26
MID ID
Number
COW War Name
257
World War I
258
World War II
261
Seven Weeks’ War
375
First SchleswigHolstein War
611
Vietnamese War
1035
Six Day War
1046
Yom Kippur War
1250
First Balkan War
1251
Second Balkan War
1265
Hungarian Allies
War
1293
1490
1535
1793
Turko-Cypriot War
Sino-Japanese War
Second Central
American War
Palestine War
MID Participants
Austria-Hungary, Belgium,
Bulgaria, France, Germany,
Greece, Italy, Japan, Portugal,
Rumania, Turkey, U.K., U.S.,
Russia, Yugoslavia
Australia, Belgium, Brazil,
Bulgaria, Canada, China, Ethiopia,
Finland, France, Germany, Greece,
Hungary, Italy, Japan, Mongolia,
New Zealand, Norway,
Netherlands, Poland, Rumania,
South Africa, U.K., U.S., U.S.S.R.,
Yugoslavia, Spain
Austria-Hungary, Baden, Bavaria,
Germany, Hanover, HesseElectoral, Hesse Grand Ducal,
Italy, Meckelnburg Schwerin,
Saxony, Wuerttemburg
Denmark, Germany, U.K., Russia,
Bavaria, Hanover, Saxony, Sweden
Australia, Cambodia, Democratic
Republic of Vietnam, Philippines,
Republic of Korea, Republic of
Vietnam, Thailand, U.S., China,
U.S.S.R.
Egypt, Israel, Jordan, Syria,
Kuwait, Iraq, Saudi Arabia
Egypt, Iraq, Israel, Jordan, Saudi
Arabia, Syria
Bulgaria, Greece, Turkey,
Yugoslavia
Bulgaria, Greece, Rumania,
Turkey, Yugoslavia
Czechoslovakia, Hungary,
Rumania, France, Italy, U.K.,
Yugoslavia
Cyprus, Turkey, Greece
China, Japan, Korea
El Salvador, Guatemala, Mexico,
U.S.
Egypt, Iraq, Israel, Jordan,
Lebanon, Syria
MID
Revision
Type
Policy
Multiparty
Status
1,3
Territory
1,3,5
Territory
1,3,5
Policy
1
Regime
1,3,5
Territory
1,3,5
Territory
1,3,5
Territory
1,3,5
Territory
1,3,5
Territory
1,3,5
Policy
Regime
1
1,3,5
Policy
1,3,5
Territory
1
27
MID ID
Number
COW War Name
3725
Ethiopian-Somalian
War
Sino-Vietnamese
War
U.K.-Egypt War
3957
Gulf War
2069
3007
MID Participants
Cuba, Ethiopia, Somalia
China, Democratic Republic of
Vietnam, U.S.S.R
Egypt, U.K., France
Canada, Egypt, France, Iraq, Italy,
Saudi Arabia, Syria, U.K., U.S.,
Jordan, Argentina, Belgium,
Bangladesh, Germany, Greece,
Morocco, Niger, Netherlands,
Pakistan, Senegal, Sierra Leone,
Spain, Turkey, Australia, Bahrain,
Kuwait, Oman, Qatar, United Arab
Emirates
MID
Revision
Type
Territory
Multiparty
Status
1,3
Policy
1,3,5
Policy
1,3,5
Territory
1,3,5
28
Appendix B: Bilateral MIDs that Escalate to War with Subsequent War-Joining
Appendix B lists all of the wars with multiple participants where there were only two
participants in the MID prior to the outbreak of war (the remaining participants joined
after the war began). The following information is presented: the MID ID number, the
name of the war from the COW War Data, the names of all participants in the MID (those
who reach level 5 hostility are in bold, the original two participants are in italics), and the
revision type of the MID.
MID ID
Number
COW War Name
51
Korean War
113
183
Italo-Sicilian War
Nomonhan War
Third Central American
War
Lithuanian-Polish War
Israeli- Egyptian War
Spanish-Chilean War
Pacific War
Lopez War
Ugandan-Tanzanian War
1205
1272
1480
1482
1518
1590
2141
MID Participants
Australia, Belgium, Canada, China,
Columbia, Ethiopia, France, Greece, New
Zealand, Netherlands, Philippines,
People’s Republic of Korea, Republic of
Korea, Thailand, Turkey, U.K., U.S.
Italy, Two Sicilies, France
Japan, Mongolia, U.S.S.R
Guatemala, Honduras, El Salvador,
Nicaragua
Lithuania, Poland, Latvia
Egypt, Israel, U.S.S.R.
Chile, Peru, Spain, Bolivia, Ecuador
Bolivia, Chile, Peru
Argentina, Brazil, Paraguay
Libya, Tanzania, Uganda
MID
Revision
Type
Territory
Territory
Territory
Regime
Territory
Territory
Other
Territory
Other
Territoty
29
Figure 1
Benefits
Equal
win-win
Costs
Equal
Unequal
zero sum
Unequal
30
TABLE 1: DISPUTE S IZE AND WAR
Multiparty
Observed #
Expected #
MID
Cond.
Dispute?
of Wars
of Wars
Total
Prob. (War)
No
59
77
1403
Yes
32
14
260
Total
91
91
1663xvi
Base probability of war = 91 / 1663 = 0.0547
Z
Sig.
.042
-2.092
.018
.123
4.850
<.001
31
TABLE 2: ISSUE TYPE AND WAR IN M ULTIPARTY D ISPUTES
Issue
Observed #
Expected #
Multiparty
Cond.
Z
p
Type
of Wars
of Wars
MIDs
Prob. (War)
Territory
17
8.62
70
.243
3.057
<.001
Policy
11
16.61
135
.082
-1.450
.074
Regime
3
5.66
46
.065
-1.198
.117
Other
1
1.11
9
.111
-0.110
.456
Total
32
32
260
Base probability of war = 32 / 260 = 0.123 (for multiparty disputes)
32
TABLE 3: LOGISTIC R EGRESSION OF D ISPUTE S IZE AND ISSUE TYPE ON WAR xvii
War
Unexponentiated
Coefficients
Robust
S. E.
Z
p > ¦ z¦
[95% conf.
Interval]
% Change in
Odds xviii
Multiparty
1.201
.255
4.70
0.000
0.700 to 1.702
232.3
Territory
1.123
.243
4.63
0.000
0.647 to 1.598
207.3
Regime
0.627
.432
1.45
0.147
-0.220 to 1.474
87.1
Other
1.323
.607
2.18
0.029
0.134 to 2.512
275.4
Constant
-3.722
.205
-18.17
0.000
-4.124 to –3.321
N=1663, Wald Chi2= 47.08, Prob. > Chi2 = 0.000, Pseudo R2 = 0.066, 94.53% of cases correctly classified
33
TABLE 4: S IMULATED PROBABILITY OF WAR
Variable Combination
Probability of
War
Multiparty - Territorial
.20
Bilateral - Territorial
.07
Multiparty - Policy
.08
Bilateral - Policy
.02
34
i
Leeds does find empirical support for this claim. Using different data than employed herein, Leeds finds
that 5.2% of bilateral disputes escalate to war as opposed to 12.5% of multilateral disputes.
ii
The business dispute literature also addresses the particularly difficult nature of multiparty dispute
resolution and the importance of underlying issues. See Menkel-Meadow (2001).
iii
Satisficing behavior is an alternative to maximizing (or optimizing) behavior. Under conditions of
bounded rationality, decision makers will attempt to achieve at least some minimally acceptable goal as
opposed to the rational actor striving for utility maximization (Simon 1957). In situations with multiple
participants negotiating an agreement, satisficing (compromise) may be the best possible outcome given
that it is unlikely that all participants could be satisfied by an agreement.
iv
The following disputes are excluded from all of the analyses below: MID number 1129 is a war according
to War Data, but not according to MID data so it is excluded; MID numbers 320, 324, 397, 518, 3813, 3826
all have only one participant that reached level 5 hostility and for that reason do not appear in the War
Data, so they are excluded. Additionally, two disputes have more than one revisionist actor with more than
one revision type coded (MID numbers 21 and 3564). These two disputes as well as any dispute where all
revisionist actors are coded as non-applicable are excluded from all of the analyses.
v
In all cases (both with MIDs and Wars) the start year and start month were available. In a few cases (with
MIDs), the start day was unknown. For those cases, we simply substituted “1”. We could have used any
other day for these cases without impacting our classification. See Appendix A for a list of all multiparty
disputes that escalate to a multiparty war and Appendix B for a list of Bilateral MIDs that escalate to a
multiparty war.
vi
Alternatively, we used two other coding schemes. The first required more than two participants in the
MID at least three days prior to the outbreak of war, reducing the number of multiparty MIDs from 260 to
256. The second required that more than two participants be in the MID at least five days prior to the
outbreak of war, reducing the number of multiparty MIDs from 260 to 253. Neither of these more
restrictive coding schemes changed the outcomes of the analyses presented herein appreciably, so results
using the least restrictive rule are presented.
35
vii
A war can still have multiple participants and not arise from a multiparty MID if states join the war after
the first day (see footnote 4 above). There are 10 cases of war-joining behavior. Given our coding scheme,
these cases are considered bilateral MIDs that escalate to war (listed in Appendix B).
viii
All exclusions listed in footnote 2 apply to this description of the data. 260 of the 1663 disputes are
classified as multiparty under our guidelines. 32 of these multiparty disputes escalate to war versus 59 of
the 1403 bilateral disputes.
ix
We found that if entry dates are not taken into consideration, then about 15.6% of all multiparty disputes
go to war and about 3.5% of all bilateral disputes go to war for the time period 1816-1992.
x
The Z-score compares the base and conditional probability of going to war. The Z-statistic is calculated
as follows: Z = (Pc-Pb) / vPb (1-Pb) / Nc where Pc = conditional probability; Pb = base or unconditional
probability; Nc = total number of cases having the condition (multiparty or bilateral), and v indicates
square root. Our use follows Bremer (1992). Significance levels based on a two-tailed test.
xi
There are four wars in the MID data with a revision type coding of “other,” the Franco-
Prussian War, the Football War, the Spanish-Peruvian/Chilean War of 1866, and the Lopez War. The
Franco-Prussian War is the one case of a multiparty war with a revision type (issue) coding of other. In the
case of the Franco Prussian war, Prussia is coded as seeking a revision of type “other”, involving a dispute
over succession rights. The revision type is coded based only on explicit claims made publicly by official
representatives of the state before the outbreak of war. However, Vasquez and Henehan discuss this issue
in more detail with particular emphasis on the territorial elements of the four “other” wars and claim that
“None of these cases indicates that there is some ‘fourth’ factor that makes more war probable than
territory; in fact three of them suggest that territory played a role in the war, even if it was not explicit in
the claims made before the war. Therefore, they should not be treated as a distinct type of issue with their
own level of probability” (2001, 129: fn 9).
xii
xiii
Policy is used as the reference category because it is the modal category.
CLARIFY is an ado file written for use with STATA in order to make data interpretation and
presentation more accessible and reader-friendly. CLARIFY employs simulation to approximate features
of the probability distribution (King, et al 2000: 349). For more information, see Michael Tomz, Jason
Wittenberg, and Gary King. (1999). CLARIFY: Software for Interpreting and Presenting Statistical
36
Results. Version 1.2.1. Cambridge, MA: Harvard University. June 1. http://gking.harvard.edu. See also,
King, et al (2000).
xiv
In order to subject proposition 3 to further scrutiny, we collapsed policy, regime, and other into a
category “non-territorial”, thereby creating a dichotomous measure of issue type (territory/non-territory)
and tested the proposition using the multiparty variable and this dichotomous measure. The results (not
shown) were supportive of proposition 3. Multiparty territorial disputes have a simulated probability of
escalation equal to 0.21, multiparty non-territorial disputes 0.09, bilateral territorial disputes 0.07, bilateral
non-territorial disputes 0.03. This model is a better predictor of escalation to war according to the
Pearson’s Chi-2 statistic; however, the model presented in Table 3 is better suited to demonstrating the
varying effects of the different types of issues as opposed to just classifying the issue at stake as territory or
non-territory.
xv
All exclusions from footnote 2 apply in the appendices.
xvi
All exclusions from footnote 2 apply to this and the following analyses.
xvii
We also ran this model with interaction terms for revision type and multiparty (not shown). None of the
interaction terms were statistically significant and the coefficients for the multiparty and revision variables
remained significant in all cases. The model with the interaction terms provided a slight (.01) increase in
the Psuedo R2 .
xviii
See Long and Freese (2001) or <http://www.indiana.edu/~jsl650/stata/> for more information.