Do the issues under dispute (for example, territory) or regime type (for example, democracy) tell us more about the propensity for international conflict? Although we believe that both variables might exert independent effects on conflict, scholars have recently debated the relative merits of the democratic and territorial peace propositions. The former argues that democratic regimes possess characteristics that inhibit their willingness or ability to fight one another militarily.Footnote 1 The latter maintains that neighboring states that settle their borders – by signing interstate agreements that delimit their entire borderFootnote 2 – provide both a foundation for peace and an environment that is hospitable to democratization.Footnote 3 As a result, some territorial scholars propose that the democratic peace is spuriousFootnote 4 – a claim that has created an ongoing debate between those who believe regime type may no longer matter for conflict involvementFootnote 5 and those who believe it does.Footnote 6
One of the key differences between these two camps concerns why democracies do not fight militarily. Does this result from the process by which democratic dyads address their disagreements or the types of issues on these dyads’ agenda? Mitchell and Prins showed some time ago that joint democracies have few (if any) militarized interstate disputes (MIDs) over territorial issues.Footnote 7 The critical question is: why is this the case? Democratic peace theorists argue this occurs because democratic dyads handle or resolve their territorial disputes peacefully, before these disputes escalate to violence. In contrast, those who argue in favor of the territorial peace maintain that democratic dyads resolve whatever territorial disagreements they may have before they become a democratic dyad. If true, then the democratic peace’s claim that democracies do not fight wars because they handle territorial issues diplomatically does not hold, since such issues were not on the agenda of these democratic dyads.
The contribution of this study is to test the temporal sequence of the settlement of territorial issues and the emergence of joint democracy for every democratic dyad since 1816. Although some existing studies examine the general relationship between border settlement and the rise of democracy,Footnote 8 these works do not speak directly to the question of whether democratic states handle territorial issues better or simply lack them. In short, there has been no systematic study of the temporal sequencing of border settlement in democratic dyads to address whether joint democratic dyads resolve their territorial issues (that is, settle their borders) before they became democratic dyads. By comparing when dyads settle their borders, we offer direct evidence on whether democratic dyads do not fight because the highly war-prone, territorial issues are never on their agenda or because their regime type causes them to handle these issues more peacefully.
Thompson foreshadows our study’s question and suggests a critical piece of evidence required to answer it.Footnote 9 He proposes that states can surrender their desire for regional hegemony, which subsequently produces both regional peace and a hospitable environment in which democracy might take root. To evaluate this claim, he then reviews four prominent historical cases, concluding that they support his general argument. Yet he also laments the lack of data required to conduct a large-n analysis of his argument and specifies precisely what evidence he seeks. In particular, Thompson writes that his ‘peace before democracy’ argument: ‘would be supported if, in most cases, regional expansion policies had been absent or abandoned prior to the advent of democratic regime types. Unfortunately, the argument does not lend itself to such a straightforward strategy at this time’.Footnote 10
We propose that Thompson asks the correct general question: do dyads clear the most contentious issues off their foreign policy agenda before both members of the dyad become democratic?Footnote 11 Examining regional primacy in its full scope, however – as he proposes – is a difficult operational task. We think his temporal question is key, but we shift the focus from regional hegemony to border settlement. The two are not unconnected: a careful reading of Thompson’s cases reveals that regional primacy largely concerns the status of neighboring states’ interstate borders – that is, whether or not such borders are settled (that is, delimited) in entirety through interstate agreements.Footnote 12 The recent availability of data on the (un)settled status of interstate borders consequently allows us to examine the temporal question Thompson raises, albeit not with his proposed variable. Thus we ask: do dyads clear the most contentious – that is, border settlement – issues off their foreign policy agenda before both members of the dyad become democratic?Footnote 13
FROM DEMOCRATIC PEACE TO TERRITORIAL PEACE
By now, the democratic peace proposition is well known: democracies do not fight wars with other democracies. This empirical finding reveals that democratic dyads are less conflictive than non-democratic dyads (that is, dyads containing at least one non-democratic state). Indeed, when scholars examine democratic dyads’ behavior, they find that these dyads experience fewer MIDsFootnote 14 and international crisesFootnote 15 and handle these disputes more diplomaticallyFootnote 16 than their non-democratic counterparts. Numerous complementary mechanisms may theoretically explain these pacific trends – for instance, various institutional constraints, or shared norms or values.Footnote 17 For the purposes of this study, however, the precise theoretical mechanism in operation does not matter. Instead, we note merely that each proposed explanation converges on the prediction that democratic dyads handle their disputes more peacefully than non-democratic dyads do.
What if, however, democracies have significantly fewer salient disputes to manage? In other words, what if democracies behave more peacefully toward one another simply because they resolve the most dangerous or war-prone issues before democracy even emerges? This is the question raised by the territorial peace proposition. For Gibler this proposition consists of three foundational tenets.Footnote 18 First, the delimitation of mutual borders within a contiguous dyad yields peaceful dyadic relations because it eliminates the most war-prone issues from the agenda. This is relatively uncontroversial. Scholars repeatedly find that territorial disputes are contentious issues that can increase the likelihood of conflict, including protracted rivalries.Footnote 19 Borders represent the most likely flashpoint for these territorial disputes.Footnote 20 Not only do borders frequently contain tangible (for example, oil, water or a militarily strategic position) or intangible (for example, symbolic) value, but they also by definition touch upon a state’s ‘homeland’, thereby allowing border disputes to threaten the core of state identity.Footnote 21 These factors make border disputes more salient than other types of disputes over which states fight. Settling such disputes therefore opens the promise of peaceful relations among neighbors. Indeed, once states settle their borders, it is hypothesized that they are less likely to fight militarily over any issue,Footnote 22 a supposition confirmed by empirical analysis.Footnote 23
Secondly, the settlement of mutual borders increases the likelihood of observing joint democracy within a dyad. This tenet seems grounded in the war-making/state-making literature.Footnote 24 Essentially, Gibler argues that unstable (that is, unsettled) borders create a salient external threat.Footnote 25 To confront this threat most efficiently, affected societies allow rulers to concentrate power (that is, to remove the constraints upon their action) and militarize the state, both of which constitute anti-democratic movement. After the threat is resolved, however, rulers renegotiate their role within society. Seeing reduced threat levels, domestic actors will attempt to place greater constraints on a ruler’s former autonomy, enhancing their own rights and freedoms in the process. These latter trends constitute movement toward more democratic societies. Of course, this democratic movement may not be swift or large; the renegotiation of a ruler’s constraints might take time, and movement is likely to be incremental.Footnote 26 Nonetheless, the territorial peace predicts that more democratic dyads will be observed after border settlement occurs.
The empirical record also supports this proposed theoretical link between border settlement and democracy. Various studies show that the absence of territorial threat is associated with democratic characteristics.Footnote 27 Gibler and Tir, for example, find that peaceful territorial transfers (that is, increased border stability) decrease militarization and encourage democratization within states.Footnote 28 Similarly, Owsiak conducts a detailed monadic analysis, which concludes that border settlement facilitates the democratization process.Footnote 29 Such findings show that resolving border issues in a neighborhood creates a benign environment for the emergence of democratic states – in conjunction with other well-known predictors of democracy (for example, greater prosperity).Footnote 30
Gibler, however, goes one step further; his third tenet argues that the findings on the territorial peace – that is, the decreased likelihood of dyadic conflict and increased likelihood of observing joint democracy within contiguous dyads after border settlement – render the democratic peace spurious.Footnote 31 This is the most controversial component of the territorial peace. Nonetheless, it can be evaluated empirically. Testing for spuriousness is not an easy task, but not an impossible one either. One approach will involve establishing several different studies that test differences between the territorial and democratic peace arguments. For instance, Park and James, as well as Owsiak, investigate the possibility that both border settlement and democracy offer distinct, independent, pacific effects.Footnote 32 They conclude that democracies may handle their territorial claims more peacefully than non-democratic dyads. Gibler and Miller, however, argue this finding may result from a selection effect, in which the types of territorial claims facing democratic dyads are substantively different than those facing non-democratic dyads.Footnote 33 Such a selection effect might appear if democratic dyads settle their borders before becoming democratic, thereby removing highly salient threats to homeland territory from a democratic dyad’s foreign policy agenda. Although Gibler and Miller do not directly test this latter possibility, their evidence remains consistent with it, and they therefore conclude that the territorial peace presents a challenge to the democratic peace.Footnote 34 These are but a few examples of what is likely to be a long debate, since whether the relationship between joint democracy and peace is spurious will involve considerably more testing before any definitive conclusion can be made.
Our study does not address the question of spuriousness. Rather, it examines the temporal aspect of that question – that is, whether border settlement or joint democracy comes first. To that limited extent, it may be relevant to the third component of Gibler’s argument. More broadly, however, our work addresses a common criticism of studies that support the territorial peace – namely, that democratic states preserve the territorial order.Footnote 35 Our skepticism of this criticism derives from existing work showing that peaceful dyads are those that have few territorial disputes, regardless of whether they are jointly democratic. Vasquez and Barrett, for example, find that most peaceful dyads that are free of militarized disputes (MIDs) since 1815 are peaceful because they do not have territorial issues in the first place.Footnote 36 Overall, 90 per cent or more of the dyads that have never had a MID have not had any pre-existing territorial claims. Conversely, a much smaller percentage of peaceful dyads are joint democracies.
Findings like these offer additional empirical support for the territorial peace proposition. Nonetheless, democratic peace proponents offer a criticism of these findings: they propose that the reason democratic dyads do not have territorial disputes is that they are better able to handle their territorial disagreements, so these disputes do not become militarized (that is, result in MIDs). One way to test the validity of this criticism is to see which phenomenon occurs first – border settlement or joint democracy.
CAUSATION AND TIMING
The purpose of our study is not to resolve all the outstanding disagreements between the territorial and democratic peace proponents. We instead aim to provide a piece of evidence on one very important testable difference between the two camps. Democratic peace proponents argue that democracies handle their disputes with one another differently. In contrast, the territorial peace suggests that dyad members settle their most contentious (that is, territorial border) issues before they both become democratic. In other words, if the territorial peace is correct, we would expect the following hypothesis to be true:
Hypothesis: Dyads are significantly more likely to settle their borders before (as opposed to after) both members become democratic states.
Before turning to our analysis, we offer three additional observations about the above hypothesis. First, if sustained, the hypothesis suggests that democracies’ handling of disputes may mean little – for the disputes they handle are significantly less likely to involve the use of military force than the disputes with which they have already dispensed.Footnote 37 This weakens a core component of the democratic peace argument that claims it is the handling of disputes – and not the issues themselves – that accounts for democratic dyads’ peaceful behavior. Conversely, if the hypothesis is not sustained, a core component of the territorial peace argument would be falsified.Footnote 38 It is therefore worthwhile to evaluate the above prediction.
To be fair to both camps, the territorial peace does not deny that democratic dyads handle all issues, including territorial issues, in a way that avoids war, but maintains that only a small subset of these dyads has territorial disagreements in the first place. From this perspective, most democratic dyads do not go to war because the most war-prone issues are not on their agenda, nor have they ever been while both dyad members were democratic. This position is consistent with the conclusion of Huth and Allee that one of the reasons democratic dyads may not go to war is that they have comparatively few territorial MIDs; they rarely threaten force to begin with.Footnote 39 It is even more consistent with the empirical finding of Reed, who in a two-stage analysis demonstrates that democracies do not go to war primarily because they do not experience MIDs in the first place, rather than because their MIDs do not escalate to war.Footnote 40 In other words, it is the paucity of MIDs – and not how MIDs are handled – that is the key determinant of peace.
Secondly, although the territorial peace claims a chronological ordering of border settlement and the emergence of joint democracy, the democratic peace does not. The democratic peace scholars who appear to come closest to such a claim are Morrow et al., who ‘speculate that the spread of systems with large winning coalitions was key to the decline of territory as an issue of dispute and the rise of the norm of territorial integrity noted by others’.Footnote 41 This untested speculation might imply a temporal ordering. We could infer from it, for example, that democratic dyads must precede the decline in territorial disputes, an inference consistent with their general argument that democratic dyads raise fewer territorial claims.Footnote 42 It is not clear, however, that the authors intend such an inference. We know that they believe democratic dyads ‘lock in’ the territorial status quo, but not necessarily why. New democratic dyads might inherit a settled territorial status quo that they then preserve (that is, fewer unsettled borders, as the territorial peace proposes) or a disputatious status quo that they subsequently settle (that is, the democratic peace); both scenarios are consistent with the authors’ sentiment. We therefore conclude that we cannot derive a sequencing argument from the democratic peace.
Finally, scholars have examined whether democratic dyads experience fewer territorial MIDsFootnote 43 or manage territorial claims differently.Footnote 44 These studies, however, miss the above hypothesis, for if the hypothesis above is correct, then democracies may behave more peacefully than non-democracies precisely because they removed contentious issues from their foreign policy agendas (that is, a selection effect exists). An evaluation of the above hypothesis may therefore explain some of these other findings as well.
RESEARCH DESIGN
In order to evaluate our hypothesis, we conduct two empirical tests. In the first, we review a series of contiguous dyads within four prominent time periods used by conflict scholars: 1816–2001, 1816–1944, 1945–1989 and 1990–2001. For each time period, we focus exclusively on contiguous dyads in which both members qualify as democratic states for the entire time period under investigation. These contiguous, democratic dyads embody the characteristics that theoretically drive the democratic peace. We therefore believe identifying and studying these particular dyads in greater detail can shed light on our key hypothesis.
In the second analysis, we then expand our focus by examining the characteristics of all 301 contiguous dyads contained in Owsiak’s data for the period 1816–2001.Footnote 45 For our purposes, contiguity requires the dyad members to share an inland or river border between their homeland territories – the closest level of contiguity in the Correlates of War Project’s Direct Contiguity Data.Footnote 46 Theory drives our decision to isolate and study these contiguous dyads. Only dyads whose homelands abut one another have mutual borders to settle (a key variable of interest for us). In contrast, those whose homelands are separated by water (for example, Mexico and Madagascar) or other states (for example, Mexico and Panama) have no mutual borders to settle. Nevertheless, we also subsequently consider non-contiguous dyads in order to address a concern held by supporters of the democratic peace that it applies to the non-contiguous domain as well.Footnote 47
We have two key variables of interest in this study. First, Border Settlement occurs when contiguous states sign an international agreement that delimits the entirety of their mutual border. We take this dichotomous measure from Owsiak, and a full list of coding criteria can be found there.Footnote 48 Three things, however, should be highlighted about this variable’s coding. First, partial settlements are insufficient to classify a border as settled. Dyads that delimit their borders in sections (for example, Afghanistan–Iran) only possess settled borders after they delimit the last section of their border. Secondly, domestic institutions must not explicitly reject the international agreements that delimit borders. If, for example, a legislature must ratify a border agreement for it to take effect, border settlement occurs if the ratification takes place. Finally, states that settle their borders are not permitted to ‘unsettle’ them, even if they find new resources in the formerly disputed region (for example, Ecuador–Peru) or leave and re-enter the system because of various wars (for example, Czechoslovakia). Border settlement therefore conveys a sense of permanence, which aligns it well with the existing territorial integrity normFootnote 49 and underscores its classification as a part of international law.Footnote 50
Our second key variable of interest is Joint Democracy (or Democratic Dyads). In keeping with existing research on international conflict, we consider a dyad to be ‘jointly democratic’ if both members of the dyad score +6 or higher on the Polity IV autocracy–democracy index.Footnote 51 Using this measurement ensures that the variable captures the strong, consolidated democracies to which the democratic peace applies – an important point, since we ultimately want to know whether dyads subject to the democratic peace proposition have cleared their contentious border issues from their foreign policy agenda. To separate these dyads from their counterparts, we will refer to any dyad that does not qualify as jointly democratic as either ‘non-jointly democratic’ or simply ‘non-democratic’.
Broadly speaking, we wish to know if dyads that eventually become jointly democratic settle their borders before or after joint democracy first appears. To ensure the robustness of our results, we conduct several variations on this basic test – for example, examining how many years before or after the dyad becomes jointly democratic that it settled its border. We discuss the specific test designs as we present our findings, along with any anomalies we discover.
EMPIRICAL RESULTS
We begin the empirical analysis by examining the timing of border settlement and the emergence of joint democracy within certain prominent, jointly democratic dyads. Toward this end, Appendix A identifies any contiguous dyad that is jointly democratic for the life of the dyad during each of the following entire time periods: 1816–2001, 1816–1945, 1946–1989 and 1990–2001.Footnote 52 We consider these ‘prominent’ cases of joint democracy, since these dyads maintain their regime status for extended time periods. After identifying these dyads, we determine the date on which each dyad settled its borders, the first date on which it became jointly democratic, and whether border settlement preceded or followed the first appearance of joint democracy in the dyad.
Table 1 summarizes the information contained in Appendix A. As the first row of Table 1 reveals, twenty-one contiguous dyads are jointly democratic for their entire history during the period 1816–2001. In almost all of these dyads (19/21 or 90.48 per cent), border settlement precedes joint democracy. For example, the United States delimited its border with Canada through a series of treaties with the United Kingdom, the last of which occurred in 1908.Footnote 53 Canada subsequently adopts the borders agreed to by the United States and the United Kingdom upon entering the international system (that is, the legal principle of uti possidetis). A similar process occurs within other dyads. Upon entering the international system, Slovenia adopts the border with Italy as settled between Italy and Yugoslavia (in 1975); likewise, Namibia accepts the Anglo–German agreement of 1890 as defining its border.Footnote 54 Each of these dyads enters the international system as a jointly democratic dyad with settled borders.
Table 1 Temporal Relationship between Border Settlement and Joint Democracy in Democratic, Contiguous Dyads, 1816–2001
Note: individual dyads presented in Appendix A. *Row percentages do not add to 100 per cent because this total includes: (1) three ‘simultaneous’ cases, in which border settlement and joint democracy appear in the same dyad-year and (2) two ‘unknown’ border settlement dates. We therefore omit these dyads from the analysis because we cannot tell whether joint democracy or border settlement came first in these dyads.
A review of the remaining time periods in Table 1 (and the dyad lists that underlie these data; see Appendix A) yields three conclusions. First, jointly democratic dyads are more common in later, as opposed to earlier, time periods (for example, two, thirteen and sixty-eight dyads in the 1816–1944, 1945–1989 and 1990–2001 periods, respectively). This is somewhat expected. The number of democratic states in the system has risen over time;Footnote 55 thus the number of jointly democratic dyads should increase over time as well. Secondly, the jointly democratic dyads cluster in Europe and the Americas. We might expect this too, as Gleditsch and Ward note that democracies cluster in space.Footnote 56 More recently, Gibler and Tir and Clay and Owsiak propose that this occurs because border settlement also clusters.Footnote 57 The pattern we observe matches what these authors cumulatively find, although the causal processes that produce the clustering remain unaddressed by our data.
Finally, we note once again that joint democracy generally does not precede border settlement. For example, within all contiguous dyads that are jointly democratic for the entire 1990–2001 period, the emergence of joint democracy occurs before border settlement in only six cases (or 7 per cent of the identified dyads): Honduras–El Salvador, Chile–Argentina, Ireland–United Kingdom, Poland–Lithuania, Czech Republic–Slovakia and Cyprus–Turkey. These anomalies run counter to the hypothesis presented earlier, and the 1990–2001 period contains more anomalies than any other period (Column 2, Table 1; the lone exception in the 1816–2001, 1816–1944 and 1944–1989 periods is the United Kingdom–Ireland). Nonetheless, in the vast majority of dyads that remain democratic throughout the entire 1990–2001 period (57/68, or 85 per cent), joint democracy does not precede border settlement. This generally occurs because borders are settled prior to independence by former colonial powers and accepted by new states (that is, uti possidetis). Regardless of the reason, however, this simple and straightforward analysis offers evidence in support of the territorial peace hypothesis.
Our second analysis expands our focus to all contiguous dyads – regardless of their regime type or how long that regime persists. For each contiguous dyad, we divide its history into a pre-border settlement period and a post-border settlement period. Then we calculate the number of contiguous dyad-years that each dyad spends as (non-)democratic in both of these periods. Finally, in addition to the raw differences, we also conduct a difference-in-means test to ascertain whether the average number of dyad-years that dyads spend as non-joint democracies and joint democracies differs in a statistically meaningful way during the pre- and post-border settlement phases. The results from these efforts appear in Table 2.
Table 2 Border Settlement and Joint Democracy in Contiguous Dyads, 1816–2001
Note: *p<0.01
The table offers additional evidence in support of the territorial peace hypothesis. First and foremost, jointly democratic dyads are very rare (that is, they exist for a statistically significant, shorter period of time) in the pre-settlement period. Pre-border settlement, dyads spend an average of 24.77 years in a non-democratic state, but only 1.21 years in a jointly democratic one. This offers prima facie evidence in support of our hypothesis. One reason this finding might occur, for example, is that very few dyads spend any time in a jointly democratic state prior to border settlement. In other words, we would observe the findings in Table 2 if, as our hypothesis proposes, border settlement chronologically preceded joint democracy within dyads. Of course, this supposition also points to a weakness of the analysis: tracking the average length of time that dyads exist with certain characteristics may mask important findings if extreme values (for example, spending zero or fifty years as a joint democracy) influence the average disproportionately. We confront this weakness directly through the additional analyses reported below.
In addition, dyads exist in a jointly democratic state for more time in the post-border settlement phase (that is, 7.11 years) than the pre-border settlement one (1.21 years). To be sure, after border settlement, dyads still spend significantly more time as non-jointly democratic, although the averages rise; dyads exist on average for 24.77 and 39.02 years as non-jointly democratic dyads in the pre- and post-border settlement periods, respectively. Non-democracies therefore clearly dominate dyadic histories, regardless of the status of borders. Nonetheless, democratic dyads exist more frequently after border settlement occurs. This finding is also consistent with the territorial peace hypothesis that border settlement might enhance the prospects for democracy to take root and hold.
Table 3 offers still more evidence that border settlement precedes the emergence of joint democracy within dyads. The table tracks the number of years between border settlement and the first appearance of joint democracy within each contiguous dyad. More specifically, for each dyad, we take the difference between the year in which the dyad first becomes jointly democratic and the year in which border settlement occurs.Footnote 58 Positive values denote that border settlement occurs first (that is, the first ‘joint democracy year’ is larger and therefore later than the border settlement year), while negative values indicate that joint democracy occurs first. As before, this analysis focuses only on contiguous dyads.
Table 3 Timing of Border Settlement and Joint Democracy in Contiguous Dyads, 1816–2001
Note: positive values denote that border settlement occurs first in the dyad. Dyads are only included in analysis if both events (border settlement and joint democracy) have occurred. Differences are left-censored at 1816.
In Table 3, we analyze only 112 of the contiguous dyads from Table 2 because we require the dyads in Table 3 to experience both border settlement and at least one year as a joint democracy. Absent this requirement, we have no way to calculate the difference described above. It is worth noting, however, that most of the omitted dyads never achieve joint democracy. Relaxing this decision would therefore only strengthen the results we present, as we would simply be admitting additional dyads that support the territorial peace hypothesis.Footnote 59 It is important to note that we rely upon the first year in which joint democracy occurs in a dyad when calculating our differences. This biases the data against the territorial peace proposition (that is, it does not ‘postpone’ the appearance of democracy in dyads for any reason), creating a tougher test for it.Footnote 60 If the territorial peace proposition still receives support under such conditions, relaxing this decision will only strengthen the evidence in support of it.Footnote 61
The data in Table 3 reveal a strong trend: border settlement almost always occurs before joint democracy in a contiguous dyad. In 75 per cent of the dyads examined, border settlement occurs at least thirty-five years before that dyad becomes jointly democratic for the first time (that is, 25th percentile). Yet this figure is low for many dyads. Border settlement occurs at least seventy years before the appearance of joint democracy in 50 per cent of the dyads examined (50th percentile) and nearly 100 years prior to joint democracy in 25 per cent of the dyads examined (75th percentile; 93.5 years). Such a finding offers important support for the territorial peace’s prediction, for it generally seems that border settlement temporally precedes the emergence of joint democracy. This finding also suggests that democratic dyads remove the most contentious issues from their foreign policy agenda before becoming jointly democratic.
There are a handful of anomalies to the general temporal ordering pattern we observe. In this analysis, there are eight contiguous dyads that become jointly democratic before border settlement occurs: Germany–Poland (1919), Poland–Czechoslovakia (1918), Chile–Argentina (1989), Honduras–El Salvador (1984), Czech Republic–Slovakia (1994), Russia–Ukraine (1992), South Africa–Namibia (1992) and Ireland–United Kingdom (1922).Footnote 62 Two points are worth noting about these cases. First, the first seven anomalies achieve border settlement within eight years of becoming jointly democratic. Ireland–United Kingdom is therefore an outlier, with joint democracy emerging seventy-seven years before the Good Friday Agreement. Nonetheless, in general, jointly democratic, contiguous dyads do not persist for long periods in the absence of border settlement. Secondly, four of the eight cases (Germany–Poland, Poland–Czechoslovakia, Russia–Ukraine and Honduras–El Salvador) revert back to non-jointly democratic dyads shortly after joint democracy first appears in the dyad. In other words, the anomalies may not be cases of consolidated democracy. Although such dyads admittedly run counter to the general trend noted above, they do not undermine the strong empirical support for the territorial peace prediction.
Of course, democratic peace proponents may raise an accurate criticism of the preceding analysis: although the territorial peace applies only to contiguous states, the democratic peace applies to both contiguous and non-contiguous states.Footnote 63 A skeptic could ask: what of the non-contiguous dyads? To address this concern, we analyze non-contiguous dyads separately in Table 4. This may seem odd, since border settlement theoretically applies only to contiguous states. It is possible, however, to design a test for non-contiguous dyads by building upon the war-making/state-making and territorial peace research. If, for example, external threat (that is, unsettled borders) drives conflict behavior and creates anti-democratic pressures (as the territorial peace theory argues), then any unsettled border might provoke a state to behave more bellicosely – whether near or far from home. We consequently use monadic data from Owsiak to measure whether or not each state settled all of its borders during the period 1919–2001.Footnote 64 Next, we construct a dyadic measure to indicate whether both members of a non-contiguous dyad have settled all of their borders. Finally, we examine the non-contiguous dyads to ascertain whether joint democracy appears more often before or after both dyad members have settled all of their borders.Footnote 65
Table 4 Border Settlement and Joint Democracy in Non-Contiguous Dyads, 1919–2001
Note: we only include dyads for which an ordering of the two events of interest can be ascertained. Thus dyads in which border settlement and joint democracy appear in the same year (‘simultaneously’) or experience neither or only one event are excluded.
The data in Table 4 confirm the conclusions reached thus far. Even in non-contiguous dyads, border settlement precedes the emergence of joint democracy. In over 68 per cent of all non-contiguous dyads and 70 per cent of all non-contiguous dyad-years, dyad members settle all of their borders before the dyad becomes jointly democratic. Importantly, these figures may understate the trend. Many anomalies to the finding – for instance, Costa Rica–Ghana or Chile–Mongolia – consist of dyad members that have very little interaction, limited military means to fight one another, or a sufficiently difficult time reaching one another militarily that they are unlikely to have fought even if they had wanted to do so. This suggests that many democratic, non-contiguous states with outstanding, unsettled borders might avoid fighting not because they are democratic, but rather because they have little about which to fight (that is, limited interaction) or limited means to do so. Nonetheless, Table 4 underscores the findings we report above, giving us greater confidence in our results.
CONCLUSION
At the outset of this study, we asked: do dyads clear the most contentious – that is, border settlement – issues off their foreign policy agenda before both members of the dyad become democratic? Our analysis reveals a strong positive response to this question. Numerous empirical analyses produce results that are always consistent with the hypothesis derived from the territorial peace theory. The overwhelming majority of contiguous dyads settle their borders before both members become democratic. Moreover, even when we consider non-contiguous dyads, we find that a sizeable majority of these dyad members settle their borders with all contiguous neighbors before they both become democratic. Such tests offer a critical piece of evidence in the debate between the territorial peace and the democratic peace. The fact that border settlement generally precedes the emergence of democracy in dyads temporally suggests that the causal story advanced by the territorial peace may be true. It also suggests that democracies behave more peacefully not necessarily because they are inherently more peaceful regimes, but rather because any disputes that arise among them are less salient than the territorial (border) ones they resolved before becoming democratic.
Such findings, however, do not necessarily mean that democracy does not exert an independent, pacific effect on dyadic interstate behavior.Footnote 66 Nonetheless, if the overwhelming number of democratic dyads have dispensed with the most contentious issues that exist in the foreign policy arena, then the remaining issues themselves, rather than their handling of issues generally, is more likely responsible for the peaceful behavior we see.
Implications and Future Research
Although the research we present here is fairly focused, its implications for the debate between the democratic peace and the territorial peace theories are quite stark. Previous research shows that one reason democracies do not go to war is that they experience few MIDs in general and almost no territorial MIDs.Footnote 67 Adherents of the democratic peace assume that this empirical pattern results from democratic dyads’ unique ability to handle their territorial disputes more peacefully than non-democratic dyads. According to this logic, these disputes either do not become MIDs or, if militarized, do not escalate to war. Our research shows that this is unlikely to be the causal process responsible for the larger empirical pattern. Rather, dyad members resolve their most salient territorial issues (long) before the dyad becomes democratic. This means that the disputes most likely to go to war are not on the foreign policy agenda of democratic dyads.
Stated differently, our study implies that the absence of certain kinds of issues – namely those found to be the most war-prone – produces the lack of war observed between joint democracies. This conclusion can be validly inferred from a temporal analysis (and really only from such an analysis). The lack of such an analysis until now has prevented a clear resolution of this point. Herein lies the major contribution of this article.
Beyond this, what are the implications of our study for the debate between the territorial and democratic peace theories? Three possible positions come readily to mind. The first is Gibler’s proposition that the territorial peace – via state (de)centralization and (de)militarization – accounts for the democratic peace.Footnote 68 Our results support Gibler’s general position on the potency of the territorial peace, but our data analysis does not test either his causal mechanism or his hypothesis of spuriousness.
Secondly, some unspecified third variable may encourage both border settlement and democracy. This seems unlikely given the strong temporal sequence we uncover, along with the frequently long interlude between border settlement and joint democracy. A more likely explanation is that, in many dyads, different variables drive border settlement and democratization. Regardless, we have not tested the hypothesis that a common third variable drives both variables of interest. Doing so would be tangential to our immediate purpose, and it is unclear that such an analysis would change the main conclusions we reach regarding the territorial peace.
Finally, one might argue that the democratic peace exists and operates, but only after dyads have settled their borders.Footnote 69 Our study seems to fit this implication best, although we would not argue that a territorial peace is a necessary condition for the democratic peace, simply because necessary conditions are rare in international relations. More reasonably, the territorial peace might make a democratic peace more probable. Our data analysis, while consistent with such a position, did not directly test this, nor could we do so with the data we have. This is a clear avenue for future research.
Additional future research might expand upon our study in two other ways. First, one could examine the behavior of non-democratic dyads that settle their borders. If the issue itself primarily determines behavior, then these dyads will also behave more peacefully toward one another after border settlement occurs – in the absence of democracy. Owsiak offers an initial analysis that suggests support for such a claim.Footnote 70 Secondly, one could examine whether the type of issue conditions a democratic dyad’s management of it. Once again, if the issue itself dominates, we should see the peaceful behavior of democracies change as we vary the salience of the disputed issue. Preliminary work in this area suggests that greater issue salience prompts democracies to behave less peacefully, even with each other.Footnote 71 Nonetheless, much research remains to be done before we have a definitive answer to such ‘big’ questions.
