Scholarly article on topic 'Democracy and armed conflict'

Democracy and armed conflict Academic research paper on "Political Science"

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Journal of Peace Research
OECD Field of science

Academic research paper on topic "Democracy and armed conflict"

Anniversary Special Issue

Peace Research

Journal of Peace Research

Democracy and armed conflict © The Author(s) 2014

Reprints and permission: DOI: 10.1177/0022343313512852

Havard Hegre (DSAGE

Department of Peace and Conflict Research, Uppsala University & Peace Research Institute Oslo (PRIO)


The article reviews the literature on the relationship between democracy and armed conflict, internal as well as interstate. The review points to several similarities between how democratic institutions affect both conflict types. It summarizes the main empirical findings and discusses the most prominent explanations as well as the most important objections raised to the finding, empirically and theoretically. To a large degree, the empirical finding that pairs of democratic states have a lower risk of interstate conflict than other pairs holds up, as does the conclusion that consolidated democracies have less conflict than semi-democracies. The most critical challenge to both conclusions is the position that both democracy and peace are due to pre-existing socio-economic conditions. I conclude that this objection has considerable leverage, but it also seems clear that economic development is unlikely to bring about lasting peace alone, without the formalization embedded in democratic institutions.


democracy, development, internal conflict, interstate conflict


The idea that democracies rarely if ever fight each other is often traced back to Immanuel Kant (1795/1991). The citizens of a (democratic) republic will hesitate before embarking on a war, for 'this would mean calling down on themselves all the miseries of war' (p. 100).1 The modern debate on the 'democratic peace' surged from the obscurity of the Wisconsin Sociologist (Babst, 1964) during the Cold War to a place of prominence in international relations around the turn of the millennium. By that time, there was a consensus that democracies do not fight each other in interstate wars. In parallel with the establishment of empirical evidence for an interstate democratic peace, several studies also indicate that democratic states have less frequent domestic armed conflicts. The argument that democracy causes peace has important implications, and may even have profoundly

influenced US policies in the buildup to the 2003 Gulf War (Owen, 2005; Gat, 2005; Russett, 2005).

The democratic peace debate fundamentally influenced IR scholarship also beyond its substantive importance. It brought a major shift toward the acceptance of large-N statistical studies within IR, as represented by the seminal designs of Bremer (1992) and Maoz & Russett (1992). Along with the studies of the more general 'liberal peace', the debate stimulated the introduction of several methodological innovations within the field, such as the treatment of reverse causation or temporal dependence. Much of this innovation was stimulated by the emerging practice of posting replication datasets, pioneered by JPR and scholars such as John Oneal and Bruce Russett.2

Below, I summarize the empirical evidence for the interstate and domestic peace propositions and the main theoretical arguments explaining them, and note the most

1 Several other enlightenment theorists precede Kant in arguing that states founded on democratic principles must also be against war (Gates, Knutsen & Moses, 1996: 6-7).

2 See Dafoe, Oneal & Russett (2013) for a summary of this productive practice.

Corresponding author:

important objections. Several similarities between the two forms of the democratic peace emerge. This is particularly true for what I see as the most critical challenge to the democratic peace, namely that both democracy and peace are due to pre-existing socio-economic conditions. This objection has considerable leverage, but it also seems clear that these conditions are unlikely to bring about lasting peace alone, without democratic institutions.

Main empirical findings

The interstate democratic peace

The interstate democratic peace has been studied at several 'levels of analysis' (Gleditsch & Hegre, 1997). At the dyadic level, there is considerable agreement that the 'absence of war between democratic states comes as close as anything we have to an empirical law in international relations' (Levy, 1989: 270).3 Important studies in favor of the proposition are Rummel (1983), Doyle (1983, 1986), and a string of studies by Bruce Russett and coauthors (e.g. Maoz & Russett, 1992, 1993; Russett & Oneal, 2001). Following the review of Gleditsch (1992), JPR became a major outlet for the debate.4 The dyadic finding has to a large degree withstood a series of counter-arguments. I discuss these in detail below.

There is less compelling evidence for democratic countries being less warlike overall - the 'monadic' level of the democratic peace. The bulk of the early large-N studies (e.g. Small & Singer, 1976; Weede, 1984), agree with Chan (1984) who found that 'relatively free' countries participated in war just as much as the 'less free'. Gleditsch & Hegre (1997) show that democracies rarely initiate wars, and Hegre (2008) that they are more peaceful overall when controlling for their military potential. Research at the system level has recently attracted renewed attention.5 Gleditsch & Hegre (1997) suggest that a world with an intermediate share of democracy may be associated with more war since the probability of war on average is highest in dyads with one democracy and one non-democracy. However, an increase in the proportion of countries that are democratic may alter the dyadic and monadic probabilities as systemic democratization affects international interactions (Russett, 1993; Huntley, 1996; Mitchell, Gates & Hegre, 1999; Kadera, Crescenzi & Shannon, 2003). Cederman (2001)

3 The 'dyadic level' refers to interactions between two countries; the 'monadic level' to the behavior of single countries.

4 Also see the reviews of the dyadic and monadic democratic peace in Ray (1993), Gleditsch & Hegre (1997), and Russett (2009).

5 See Harrison (2010) and Snyder (2013) for recent reviews.

rephrases the standard account of Kant (1795/1991), seeing the development of the democratic peace as a dialectic process where states gradually learn to form (democratic) pacific unions. He shows that the risk of war between democracies has been falling over the past two centuries. The risk of non-democratic war has also declined, but less swiftly. Relatedly, Mitchell (2002) shows that non-democracies in the Americas became much more likely to settle territorial claims peacefully when the proportion of democracies in the system increased. Gartzke & Weisiger (2013), on the other hand, argue that regime type becomes a less salient indicator of 'otherness' as more states become democratic, and their empirical analysis indicates that the risk of conflict between democracies has increased as the world has become more democratic.6

Studies using tools of network analysis also indicate systemic effects of democracy. Dorussen & Ward (2010) and Lupu & Traag (2013) find support for the democratic peace while accounting for the pacifying impact of trade networks. Maoz (2006) finds that large 'democratic cliques' in networks dampen conflicts, but Cranmer & Desmarais (2011) conclude that the support for this claim is weak when using a more appropriate statistical method.

The internal democratic peace

A number of studies find empirical confirmation of an 'inverted-U' relationship between level of democracy and the probability of onset of internal armed conflict. Semi-democratic regimes have a higher risk of internal conflict than consistent autocracies or democracies (Boswell & Dixon, 1990; Muller & Weede, 1990; Hegre et al., 2001; Fearon & Laitin, 2003). The existence of this 'inverted U' has been challenged, however (Elbadawi & Sambanis, 2002; Collier & Hoeffler, 2004; Vreeland, 2008).7 In any case, very few studies find traces of a monotonic effect of democracy. When controlling for GDP per capita or other indicators ofsocio-economic development, democratically governed countries have no lower risk of internal armed conflict than autocratic ones.8

6 The empirical analysis in Gartzke & Weisiger (2013) is contested in Dafoe, Oneal & Russett (2013), however.

7 See Gleditsch, Hegre & Strand (2009), including a discussion of whether one should control for the stability of institutional constellations.

One partial exception is Cederman, Wimmer & Min (2010) who find that systematic exclusion of ethnic groups from political power increases the risk of conflict.

Buhaug (2006) finds that semi-democracies have a higher risk of wars over government than autocracies and democracies, but that democracies are more likely to experience conflicts over territory than the other two regime types. Cederman, Hug & Krebs (2010) find democratization to affect conflicts over government, but not over territory.

Although democratic institutions by themselves are ineffective in reducing risk of internal conflict onset, several studies find that they affect how internal conflicts evolve. Lacina (2006) and Gleditsch, Hegre & Strand (2009) show that internal wars in democracies are less lethal. Democratic governments make use of less violence against civilians (Eck & Hultman, 2007) and engage in less repression (Davenport, 2007b; Colaresi & Carey, 2008),9 but rebel groups tend to make more extensive use of violence against civilians when fighting democratic regimes (Eck & Hultman, 2007). Possibly because of the stronger constraints on the use of violence against insurgents, democracies tend to have longer internal wars (Gleditsch, Hegre & Strand, 2009).10

Some studies, such as Mukherjee (2006), find that post-conflict democracies have a lower risk of conflict recurrence. Other studies report contrasting results (Walter, 2004; Quinn, Mason & Gurses, 2007; Collier, Hoeffler & Soderbom, 2008).


Interstate conflict

Although there is scholarly agreement that democracies rarely if ever have fought each other, there is less consensus as to why. The following five sets of explanations are important:

First, the normative explanation (Doyle, 1986; Maoz & Russett, 1993) holds that 'the culture, perceptions, and practices that permit compromise and the peaceful resolution of conflicts without the threat of violence within countries come to apply across national boundaries toward other democratic countries as well' (Ember, Ember & Russett, 1992: 576). States 'externalize' the domestic norms that encourage compromise solutions and reciprocation, and strictly inhibit the complete removal from political life of the loser in political contest.

The absence of a monadic democratic peace is troublesome for the normative explanation, in particular

9 See Davenport (2007a) for a comprehensive review.

10 Collier, Hoeffler & Soderbom (2004), Fearon (2004), and DeRouen & Sobek (2004), on the other hand, find no link between regime type and duration of conflict.

since it implies that the probability of conflict between democracies and non-democracies must be higher than that between two non-democracies (Raknerud & Hegre, 1997). Rosato (2003) points to the frequent violation of liberal norms when democracies have decided to go to war - in imperial wars, as well as in frequent US interventions intended to overthrow democratically elected governments (Rosato, 2003: 589-590).11 Another notable caveat noted as early as in Kant (1795/1991), is the incentive to intervene in non-democracies to press for democratization (Peceny, 1999; Gleditsch, Christiansen & Hegre, 2007). A particularly critical view of democratic war behavior is found in Geis, Brock & Muller (2006).

Second, according to the legislative constraints explanation, democratic leaders are constrained by other bodies (such as parliaments) which ensure that the interests of citizens and powerful organizations are taken into account. Debate is public, so information on the real costs of war is likely to enter the decision calculus. Democratic political leaders will be removed from office if they circumvent these constraints.12

Democracies' ability to signal resolve is a third explanation. Why are states not able to agree to a solution that reflects the distribution of power and the actors' 'resolve', without incurring the costs of war (Fearon, 1995)? One answer is that if crisis escalation is not very costly, both parties have an incentive to exaggerate their power or resolve, mobilize, and back down when the bluff is discovered. Fearon (1994) argues that audience costs - the costs that a leader suffers when backing down - lock leaders into their positions, increasing the costs of bluffing. Democracies have higher audience costs, Fearon argues, and may more credibly commit to policies with little crisis-inducing behavior to signal intentions.13

Making use of various empirical strategies to distinguish the explanations, Schultz (1999) and Prins (2003) find stronger support for the signaling argument than for the constraints explanation. Weeks (2008) builds on this argument by showing that single-party regimes also indicate behavior in line with a signaling argument. Downes & Sechser (2012), Snyder & Borghard (2011), and Trachtenberg (2012), on the other

11 Also see Downes & Lilley (2010). Rosato's argument was countered by Kinsella (2005) and other contributions in the same issue of APSR.

12 See Choi (2010) for empirical support for this explanation.

13 The audience cost and legislative arguments arguably also imply a monadic democratic peace.

hand, find little empirical evidence for the audience

cost argument.

Fourth, in a mobilization argument Bueno de Mesquita et al. (1999, 2003) argue that the democratic re-election pressures on leaders tend to make them more careful to select only wars they are likely to win, and to mobilize more resources for the war efforts they select than do autocratic leaders. This makes democracies unattractive targets, since they are likely to win the wars they fight (Reiter & Stam, 1998).15 Both of these tendencies tend to reduce the probability of war between democracies.

One aspect of the effectiveness of democracies in war is their ability to form large alliances in important wars (Doyle, 1986; Raknerud & Hegre, 1997). The empirical analysis in Gartzke & Gleditsch (2004), however, suggests that democracies are less reliable allies. Leeds, Mattes & Vogel (2009), on the other hand, find that countries with democratic institutions are much less likely to abrogate international commitments than autocratic countries in instances where domestic leadership transitions result in leaders with different primary bases of societal support.

Fifth, Gartzke (1998) points out that the democratic peace finding might be due to joint interests. Democracies may fail to disagree sufficiently on international policies to be willing to suffer the costs of war. Such joint interests may be due to the fact that most democracies were on the same side during the Cold War (Farber & Gowa, 1995).16 The failure to observe a monadic democratic peace (Gartzke & Weisiger, 2013: 172) and the observation of an 'autocratic peace' (Werner, 2000; Peceny, Beer & Sanchez-Terry, 2002) support this argument.17 An autocratic peace can hardly be explained by constraints inherent in autocratic regimes, but must be due to shared interests.

Gartzke (1998, 2000) shows that controlling for joint interests weakens the magnitude and significance of the evidence for a democratic peace.18 Joint interests and

14 But see the debate in Security Studies 21 (3) following Trachtenberg's article.

This proposition is contested, however. See Brown et al. (2011) for a collection of essays on democracies and war victory.

16 Gowa (2011: 169) maintains that 'dispute and war rates by dyad type converge after the collapse of the bipolar system' using much more recent data. This conclusion is contested by Park (2013), however.

17 Raknerud & Hegre (1997), however, demonstrate that the

'autocratic peace' to a large extent is due to the tendency for

democracies to ally with each other in large multi-actor wars.

Note that Oneal & Russett (1999) question how much the democratic peace is due to joint interests.

joint regime types may be linked through three pathways. First, joint democracy may itself give rise to joint interests, such as an interest in the promotion of democratic regimes or through similar incentives for political leaders to expand the territory they control. The profitability of occupation is less certain for democratic leaders than for autocratic countries, since the benefits of occupation have to be shared between almost as many as those who bear the costs (Rosecrance, 1986). Moreover, in order to extract much from the conquered territory, the people resident there have to be denied the political rights that are held by the citizens of the occupying country.19 Hence, joint democracy may lead to the mutual acceptance of international borders, removing an important source of war (Huth & Allee, 2002). Relatedly, Schweller (1992) argues that regime type affects how declining powers behave. When challenged by rising powers, realist theory posits that leading powers wage preventive wars to maintain their military hegemony. Preventive wars are less attractive to democratic leaders. If the rising power is another democracy, the historical absence of war between democracies indicates that the threat is minimal. If it is non-democratic, the public is wary of the risks and costs of a war where the danger is not imminent, and the formation of alliances to counterbalance the non-democratic threat is often a preferable _ _ 20 strategy.

Internal conflict

The earliest arguments for an internal democratic peace are related to the normative and structural explanations of the interstate variant. Democracy is seen as a system for peaceful resolution of conflicts, as conflicting claims by rival social groups are solved by majority votes or consensual agreements. If individuals are denied the political rights and the economic benefits they believe they are entitled to, they may react with aggression and organize violent political opposition. If conflict results from 'relative deprivation' (Davies, 1962; Gurr, 1968), democracies should be more peaceful internally than other regime types. Armed rebellion will not be profitable since democracies both allow discontent to be expressed and have mechanisms to handle it.

Another argument holds that democratic institutions alter the risk of internal conflicts by facilitating effective bargaining and reducing commitment problems.

19 Such dual standards certainly exist, but they often imply some normative costs related to the occupation.

See Levy (2008) for an extensive review of this argument.

Acemoglu & Robinson (2006: 24-25) note that citizens are excluded from de jure power in a non-democracy. Still, they always enjoy some de facto power that sometimes allows citizens to obtain policy concessions from the elites in the short run. It is uncertain whether these will be maintained, however, since the balance between various social groups is transitory. Citizens, then, should demand that today's de facto power is translated into de jure power that secures long-term concessions. This demand may be backed by a threat of revolution - a civil war. The elites cannot credibly commit to a promise of policy concessions in the indefinite future, however, as long as de facto power is transitory. Democratic institutions are the solution to this commitment problem (Acemoglu & Robinson, 2006). This explains democratization and shows why democratic institutions reduce the risk of (revolutionary) civil wars. Fearon (1995) likewise argues that bargaining failures and commitment problems are important explanations of war, and Fearon (2004: 288) argues that democratic regimes facilitate bargaining and credible commitments for internal conflicts.21 If either of these accounts is true, fully fledged democracies are less conflict-prone than repressive autocracies. One possible reason for not observing this is that democracies often are faced with opportunistic rebels whose aims do not reflect the interests of broad social groups. For internal conflicts, a parallel to the mobilization argument formulated for interstate conflict would encounter difficulties. Both democracies and non-democracies use military force to counter illegitimate armed opposition, but autocracies may make much more extensive use of repression without losing legitimacy - using violence to silence opponents, censorship, arbitrary imprisonment without trial, etc. Autocracies may indiscriminately target entire population groups to coerce influential individuals (Davenport & Armstrong, 2004; Carey, 2010).22 Autocracies also buy off other parts of the opposition by granting ministerial posts and by the selective channeling of public funds (Fjelde & de Soysa, 2009). The combination of these two methods allows effective divide-and-rule strategies. Autocracies also repress the formation of organizations before they can reach the stage of armed insurgencies. Hence, regimes that feature both democratic and autocratic characteristics are partly open yet

21 These views of democratic institutions as commitment devices are related to the signaling explanation for the interstate democratic peace.

22 Also see Davenport (2007b).

lack effective means of solving conflicts. In such political systems, repression is difficult since some organization of opposition groups and some opposition expression of discontent are allowed, but mechanisms to act on the expressed discontent are incomplete (cf. Davies, 1962; Boswell & Dixon, 1990; Muller & Weede, 1990; Hegre et al., 2001). Hence, repression is ineffective if 'grievance' is not simultaneously being addressed, which is why we observe an inverted-U relationship between democracy and peace.

All in all, precisely because of the constraints on indiscriminate use of force, democracies may be disadvantaged when faced by opportunistic rebel groups. This claim has recently been contested, however. Analyzing data for insurgencies over the 1800-2006 period, Lyall (2010) finds no evidence that democracies are more frequently defeated or have to sustain conflict for longer periods.

Does democracy cause peace?

Empirically, the correlation between democracy and interstate peace is well established, as is the correlation between consolidated democracies and absence of internal conflict. Still, this does not necessarily mean that democracy causes peace. Two main objections have been raised to that causal inference - peace may cause democracy, or some other societal factors may cause both democracy and peace. Since these counter-arguments largely focus on what explains democratic institutions at the country level, the arguments apply to the domestic as well as the interstate democratic peace.

Putting the cart before the horse?

An implicit assumption in many statistical studies of the democratic peace is that the causal arrow goes from democracy to peace. Although not dismissing the pacifying effect of democracy completely, Thompson (1996) and Rasler & Thompson (2004) show that geopolitical constraints that were in place before democratization can account for the subsequent peace. Layne (1994: 45) argues that democratic regimes can afford democratic systems, 'because there is no imminent external threat that necessitates a powerful governmental apparatus to mobilize resources for national security purposes'. Boix (2011) shows that democratization has been more frequent during periods where democracies have been hegemonic powers. Gates, Knutsen & Moses (1996: 5) add that peace leads to trade, investment, and economic growth, and thereby to democratization. Indeed, the idea of a reverse causation goes at least back to Wright (1965/1942: 841).

Mousseau & Shi (1999) discuss the temporal aspects of the issue, and conclude that there is little evidence that autocratization tends to occur during or after wars - in fact, the opposite may be the case when democracies win the wars (Mitchell, Gates & Hegre, 1999). The main threat to the democratic peace proposition is change toward autocracy in anticipation of war. By means of interrupted time-series analysis, Mousseau & Shi (1999) find no clear trend of states changing toward autocracy before wars. Using instrument-variable methods, Kim & Rousseau (2013) agree that the democracy-peace correlation holds even when accounting for the pre-existing amount of violence in a region. Reiter (2001) finds that international conflict rarely blocks transitions to democracy. The simultaneous-equation analysis in Reuveny & Li (2003) shows that conflict reduces democracy, but also that democracy reduces conflict.23 In all, most attempts to ascertain the direction ofcausality by means ofappropriately designed statistical methods seem to support the core tenet of the democratic peace, although there are dissenting voices such as James, Solberg & Wolfson (1999).

Gibler (2007) formulates a more specific reverse-causation argument. He points to Boix (2003) who notes the importance of the settlements of territorial claims in 17th- and 18th-century Europe. Without these, the fundamental economic changes required for democratization would not have happened.24 Such territorial agreements, then, indirectly give rise to clusters of democracies that have joint interests in keeping a separate peace. The empirical analysis in Gibler (2007) indicates that exogenous predictors ofborder stability tend to decrease the likelihood ofterritorial disputes and increase the probability ofjoint democracy, and that the evidence for the democratic peace is weaker when predictors ofbor-der stability are controlled for. The conclusions remain in doubt, however, as Park & Colaresi (forthcoming) report inability to replicate the results. Gibler & Tir (2010) expand the notion of territorial settlements to one of'positive territorial peace', and show that peaceful territorial transfers lead to democratization and lower levels of militarization.

The issue of reverse causation has not been equally prominent in the study of democracy and internal

23 The analysis in Reuveny & Li (2003) is hard to interpret, however, since they attempt to model the effect of conflict on the democracy level of both states in the dyad, using a weak-link design that seems partly inappropriate.

24 Boix (2003: 228) notes, however, that territorial settlements are

not the only explanation of the European 'growth miracle'.

conflict, with some notable exceptions in particular in studies of repression and violence (Carey, 2006; Moore, 1998). The relative-deprivation argument, however, implies reverse causation. Ifdeprivation is due to the lack of political rights, and civil war is a useful strategy to obtain such rights, war should lead to democracy. In contrast to this expectation, however, Gleditsch & Ward (2006) do find that civil wars tend to undermine democracies but do not affect the durability ofautocracies.

What drives democratization and peace? Perhaps the most serious challenge to the democratic peace comes from arguments suggesting that both democracy and peace are outcomes ofmore fundamental societal changes. Most of these are associated with socioeconomic development.

Institutional consolidation. A possible indication of this is that the interstate democratic peace is weaker for young democracies (Maoz & Russett, 1992). Indeed, the process of democratization may increase the risk of war in the short run (Mansfield & Snyder, 1995).25 Relat-edly, changes in the political institutions of a country are likely to be accompanied by a heightened risk of civil war (cf. Snyder, 2000; Hegre et al., 2001; Fearon & Laitin, 2003; Cederman, Hug & Krebs, 2010). Firstly, changes in a democratic direction are likely to be accompanied by reduced repression, allowing communal groups to mobilize. In addition, it takes a long time to make new institutions sufficiently efficient to accommodate deep social conflicts. Groups that increase their political influence will raise their expectations of real improvements in their living conditions, but these can be slow to materialize. Losers from the institutional changes, then, have an incentive to incite armed insurgencies to re-establish the previous status quo.

Fearon & Laitin (2003: 85) interpret the inverted-U finding for internal conflicts as due not to the institutional characteristics themselves, but to an underlying conflict over the setup of the system: '''anocracies'' are weak regimes, lacking the resources to be successful autocrats or containing an unstable mix ofpolitical forces that makes them unable to move to crush nascent rebel groups'. This interpretation is supported by Gleditsch & Ruggeri (2010). Their proxy of instability (a variable recording recent irregular transitions of power) is associated with a high risk of conflict onset. Moreover, when

25 See, however, the critiques of Mansfield & Snyder in Ward & Gleditsch (1998), Narang & Nelson (2009), and Bogaards (2010).

controlling for it, they find a monotonic negative relationship between democracy and risk of conflict.

Elections provide a special case of change - not to the institutions, but to the de jure distribution of power within electoral regimes. In new democracies, there is considerable uncertainty whether the main actors are truly committed to respecting the outcomes of elections. Most actors prefer to secure power by means of electoral victory since it bolsters the legitimacy of their rule. If they lose, however, they may find an attempt to seize power by force preferable to accepting the defeat. Several studies confirm that elections tend to be followed by an increased risk of internal conflict (Collier, Hoeffler & Soderbom, 2008) or ethnic conflict (Cederman, Gleditsch & Hug, 2013).

Market norms. Mousseau (2000) argued that both democratic consolidation and the democratic peace are due to a specific set of norms of contracting. These norms emerge in economically developed countries by a 'process of cultural materialism'. Economic development requires a complex division of labor which typically is achieved through a dense web of voluntary contracts. These contracts pave the way for democratization since they foster norms of negotiation, trust, equity between contractees, and respect for property rights. The international manifestation of such norms is more peaceful behavior, since wars of conquest would violate these norms. An implication of this argument is that only developed democracies can maintain a separate peace. This expectation is supported in a set of statistical studies of interstate conflict (Mousseau, 2000; Mousseau, Hegre & Oneal, 2003; Hegre, 2000) and internal conflict (Hegre, 2003; Collier & Rohner, 2008).

Controlling for a more direct measure of 'contract-intensive economies' (CIE), Mousseau (2009: 82) concludes that 'democracy is not a likely cause of peace among nations'. Dafoe, Oneal & Russett (2013), however, reject this conclusion. Still, they do find support for the effect of CIEs controlling for joint democracy and acknowledge that there is some overlap between the democratic peace and the effect of CIEs (Dafoe, Oneal & Russett, 2013: 209).26

26 Dafoe, Oneal & Russett (2013) show that Mousseau's main inference hinges on an erroneous interpretation of the interaction term between democracy and CIE - in their replication, joint democracy retains considerable explanatory power even when controlling for the CIE term. They also question the quality of the proxy variable for CIEs used by Mousseau (2009).

Lootability. Another aspect of economic development is that it favors non-lootable or non-appropriable assets over lootable assets - 'commerce' is gradually replacing 'conquest' since 'labor, capital, and information are mobile and cannot be definitively seized' (Rosecrance, 1986: 48).

This development-related change has an analogy in internal conflicts. When land-based assets such as most primary commodities are economically dominant, states have strong incentives to use physical force to retain control, and potential insurgents have similar incentives to try to seize control over the central power or to obtain larger autonomy for a region. This argument reflects the importance placed on primary commodity exports by Collier & Hoeffler (2004) and Fearon & Laitin (2003). Several rebel economic activities require high rebel territorial control, such as taxation of natural resource production, rich landowners, or household incomes (Fearon & Laitin, 2003). In the words of Boix (2008: 432), 'In economies where wealth is either mobile or hard to tax or confiscate, sustained political violence to grab those assets does not pay off since their owners can either leave in response to the threat of confiscation or are indispensable to the optimal exploitation of assets.' Boix finds strong empirical evidence for this account. It is supported by numerous empirical studies that show that extensive reliance on the export of oil - a highly appropriable asset - is associated with conflict as well as authoritarian rule (Fearon & Laitin, 2003; Fjelde, 2009; Ross, 2001). Relatedly, the models of democratization in Boix (2003) and Acemoglu & Robinson (2006) provide an explicit link between democratization and civil war - elites agree to democratization because they fear a revolution staged by the poor. Democratization, they argue, is least likely when inequality is extensive, since the redistributive tax rate preferred by the median voter then will be very high. Revolutions, then, will be more frequent in unequal societies, since the elites have a stronger incentive to resist democratization.

If the assets that the rich control are in the form of land or other resources that cannot be moved out of the country, the poor will be able to impose radical taxes if they get to control the tax rate (Boix, 2003). If most of the wealth is in the form of financial capital, a larger fraction of it is 'safe' from taxation, and democratization is less threatening. Moreover, where lootable assets are predominant, rebel groups have incentives to stage limited campaigns not to entirely take over the government, but to secure local access to profitable natural resources.

Joint interests. The democratic peace seen as merely 'joint interests' (Gartzke, 1998) may also be a function of economic development, as noted in Rosecrance (1986) and Gartzke (2007). Well into the 20th century, an 'obsession with land' was the major cause ofwar since states could improve their position by seizing other nations' territory (Rosecrance, 1986: 48). During the 20th century, however, mobile factors of production -capital and labor - surpassed land in importance for productive strength. At the same time, nationalist resistance to occupation became more frequent, increasing the cost of extracting resources from a territory (also see Boix, 2003: 44-45). In addition, the diversity of resources employed speaks against a military strategy (Rosecrance, 1986; Brooks, 1999). Development may provide the motive and means for a state to seize a particular territory from another by force, but it also increases its dependence on third parties. War hampers trade with third parties either because ofpolitical reactions or because the heightened risk resulting from conflict increases the price of traded goods. The constraints imposed on developed states through their extensive trade with a great number ofother nations are apt to outweigh the prospect ofgain-ing control over one particular territory.27

Developed societies that are economically reliant on the revenues from international trade and investment place much more emphasis on the protection of property, political stability, and the integrity of international borders than on expanding own territories. Developed societies, then, have a joint interest in restricting attempts to expand territories, such as Saddam Hussein's conquest of Kuwait, and a lack of interest in contesting own borders. Similar joint-interest explanations also apply to internal conflicts and to the incentives to resist democratization. Economic development, in particular the reliance on relations with international markets, also means that a large set ofactors become reliant on preserving political stability.

Interdependence. In several theories of democratization (Dahl, 1971; Olson, 1993; Boix, 2003), the high costs of violence and repression in densely interacting societies is an important factor. Dahl (1971) sees 'modern dynamic pluralist' societies as an essential prerequisite for democracy - democracy prevails because citizens can credibly threaten to hurt the elites economically by means of

27 Supportive of this view, Hegre (2000) and Mousseau, Hegre & Oneal (2003) indicate that the pacifying impact of trade is conditional on the level of development.

strikes, protests or exiting the country. The diversification and division of labor in developed economies leads to both democracy and internal peace.

For interstate conflict, a similar argument states that strong dependence on trade and on capital constrains belligerent actors (Angell, 1910; Russett & Oneal, 2001). Domestic and foreign capital is likely to flee the country if war breaks out. Less capital-intensive economies are less constrained by these considerations (Gartzke, Li & Boehmer, 2001). In a critical review of the democratic peace, Gat (2005, 2006: 658) argues that it has overlooked the industrial revolution: 'Rather than the cost of war becoming prohibitive ... it was mainly the benefits of peace that increased dramatically once the Malthusian trap was broken, tilting the overall balance between war and peace for ... industrializing and industrial societies, regardless of their regime, for which wealth acquisition ceased to be a zero-sum game.'

The capitalist peace. Gartzke (2007) argues that the liberal peace really is a 'capitalist peace'. The rhetoric value of this term is greater than its precision. In effect, Gartzke's argument draws on several of the effects of socio-economic development reviewed above. Interdependence and mobility of assets are equally important as the particular economic freedoms and financial structures traditionally associated with 'capitalism'. Echoing Rosecrance, Gartzke (2007: 172) argues that development 'leads states to prefer trade to theft', but does not weaken their resolve to defend their borders. At the same time, developed states are typically militarily powerful and are able to wage wars over long distances. since many wars are fought over non-territorial issues (e.g. to defend a particular political system in another state, or to prevent the development of nuclear capabilities), developed states are willing to fight long-distance wars where conquest is not the motivation. This leads Gartzke to expect that development leads contiguous dyads to be less likely to experience militarized interstate disputes and non-contiguous dyads to be more likely to do so. He finds support for both these hypotheses, and finds that the terms representing the democratic peace are non-significant when controlling for the 'capitalist' factors. Gartzke & Hewitt (2010) obtain similar results for international crises.

The capitalist peace challenge to the democratic peace is taken up by Dafoe (2011) and Choi (2011), who show that the democratic peace retains support in the model of Gartzke (2007) with some specification changes that most analysts would agree are improvements to the original. The complete replication results presented in choi

(2011) show, however, that the substantial effect of the democratic peace is weaker when controlling for 'capitalist' factors than without, and Gartzke's main hypotheses retain support in their replications.

Any residual effects of democracy?

The arguments reviewed here may imply that socioeconomic development is an important pre-condition for the democratic peace, in the context of both interstate and internal conflicts. It would be premature to conclude that development completely removes the importance of democratic institutions, however. First, if the economic underpinnings for democracy were sufficient for citizens' welfare, we would not have seen the systematic trend of transitions toward democracy when states become economically more developed (Przeworski et al., 2000; Boix, 2003, 2011). Because of commitment problems, the 'invisible hand' of the market is insufficient to prevent conflict. Both elites and citizens see the need to design institutions that formalize access to decisionmak-ing power and also bind both sides to this formalization should the underlying balance of power change at some point in the future.

One might also argue that development presupposes some kernels of democratization. For instance, the emergence of market norms crucially depends on the protection of property. Effective autocratic governments can protect property against 'roving bandits', but have a harder time assuring market actors that they will resist the temptation to confiscate the property of citizens. This, according to Olson (1993: 572), can only happen when rulers have very long time horizons, and long time horizons are credible only in democratic systems: 'History provides not even a single example of a long and uninterrupted sequence of absolute rulers who continuously respected the property and contract-enforcement rights of their subjects.' Indeed, Olson (1993: 574) claims that 'Individual rights to property and contract enforcement were probably more secure in Britain after 1689 than anywhere else, and it was in Britain, not very long after the Glorious Revolution, that the Industrial Revolution began.' If so, democracy is causally prior to development. At least, it is likely that democracy and economic modernization have developed in a dialectic process not unlike the Kantian learning process discussed in Cederman (2001). This process is probably related to a general shift in norms against the use of violence. Several of the long-range processes discussed in Gat (2006) and Pinker (2011) may be seen as informing explanations of democratization as much as explanations for the decline of war.

Moreover, democracy and development may require each other to produce socially optimal outcomes. Mousseau (2000) and Mousseau, Hegre & Oneal (2003) find that the effect of democracy is contingent on development. Dafoe, Oneal & Russett (2013: 206) acknowledge that democracy and development might mutually reinforce each other: 'Economic norms may express themselves more forcefully in liberal polities; moral concerns weigh more heavily when people are rich; the stability and bargaining credibility made possible by democracy ... is more robust when governments are dependent on capital.' Moreover, development in general strengthens and stabilizes democratic institutions (Przeworski et al., 2000; Gates et al., 20 06),28 and developed democracies should therefore be better able to constrain leaders and affect their audience costs and incentives to avoid failed wars.

In the case of domestic conflict, Hegre (2003), Collier & Rohner (2008), and Gleditsch, Hegre & Strand (2009) also find democracy to reduce the risk of internal conflict more effectively in high-income countries. This may be because the democratic strategies for maintaining order may be more costly than the autocratic strategies. Identifying and prosecuting individuals within groups that make use ofillegal means ofprotest takes more resources than indiscriminate repression of the entire group. To maintain a democratic civil peace, the government must be capable of not only actively affecting the societal distribution of resources but also preventing abuses of one social group by another. Most democracy datasets measure the extent to which governments are accountable and constrained, but rarely capture their capabilities to implement their decisions. Hegre & Nygard (forthcoming) indicate that such capabilities are just as important as the de jure institutions. Relatedly, political systems that combine democratic and autocratic features, for instance, may be regarded as having low capability because of their lack of consistency (Gates et al., 2006; Gleditsch & Ruggeri, 2010). Kalyvas & Balcells (2010), moreover, show that after the end of the Cold War, an increasing proportion of internal conflicts have been 'symmetric non-conventional' where both the government and the rebels lack the capacity to fight regular wars. This trend coincides with an increased number of low-income, low-capacity democracies, in particular in sub-Saharan Africa.

Development also affects the policy incentives for democratically elected leaders. Illiterate populations are

28 However, see Boix & Stokes (2003).

often unable to make use of the democratic institutions to constrain the elected leaders. Elected offices are extremely valuable to their incumbents in societies with immobile assets and extensive inequality (Boix, 2008), widespread corruption, and few alternative economic opportunities, inducing incumbents to concentrate on retaining power rather than serving the electorate. In sum, leaders in low-income democracies may be both less able and less willing to address social conflicts that underlie 'relative-deprivation' mechanisms.

Development does not have the same effect in non-democratic systems. Hegre (2003) indicates that violent conflict becomes more frequent in authoritarian states as they modernize. This is in conflict with the empirical implications of the 'opportunity' (Collier & Hoeffler, 2004) or 'feasibility' accounts of conflict (Collier, Hoeffler & Rohner, 2009). Development, to the extent it fosters 'modern dynamic pluralist' societies, may tend to shift the balance in favor of 'justice-seeking' rather than 'loot-seeking' motivations for internal conflicts, since the education, urbanization, and economic leverage associated with development raise the political expectations of citizens and help them resolve their collective action problems. It is clear that demands for democratization tend to intensify with higher education levels and the increased dispersion of economic leverage in modern economies. As exemplified by the recent conflicts in Libya and Syria, elites that resist these demands run a risk of escalating such conflict to civil war. Economic development may be a necessary condition for the democratic peace, but not a sufficient one.

On the other hand, the autocratic means to maintain order do not become more effective with increasing development. First, widespread repression is more likely to meet widespread popular resentment the more educated the population is. With more human and social capital at hand, citizens are better able to force a repressive government to change its behavior. Eventually, the elites may be forced to open up the political system to allow the formation ofdemocratic political systems. This transition process is often associated with civil conflict.


This review has discussed recent research on the relationship between democracy and armed conflict, covering both conflicts internal to countries and interstate conflicts. Although there are many differences between the interstate and domestic conflict, the review indicates there are also several similarities. In particular, some important challenges to the democratic peace apply to

both types of conflict. The most fundamental challenge, in my view, is that there might be underlying social changes that explain both the development of democratic institutions and peaceful resolution of social conflicts. These changes are typically summarized as socio-economic development, and typically work through the incentives for using physical force for political goals. At the same time, as recently seen in Syria, relative economic development in itself is not sufficient to prevent armed conflict. Democratic institutions are formal codifications of nonviolent conflict resolution procedures. Socioeconomic development is likely to change societies such that nonviolent conflict resolution is an underlying pareto-optimal equilibrium, allowing actors to agree to such codifications. In the absence of formal codifications, however, actors may be unwilling to trust that this underlying equilibrium exists. Hence, democratic institutions may be necessary to allow the beneficial changes due to development to be manifested as more peaceful societies.

The review suggests several avenues for future research. First, there is no consensus on the relative importance of multiple explanations of the empirical observations. A recurrent challenge is to identify empirical implications that allow distinguishing clearly between them. This requires new data - democratic peace research tends to rely excessively on a very limited number of datasets. This is particularly true for the measure of democracy, where most studies use the Polity dataset (Jaggers & Gurr, 1995; Marshall, Gurr & Jaggers, 2013). Disaggregating the institutions along the lines of Carey (2007) and Fjelde (2010) will be helpful, as well as making use of new datasets measuring various aspects of democratic institutions (e.g. Boix, Miller & Rosato, 2013; Regan, Frank & Clark, 2009; Coppedge et al., 2011).

Another avenue to explore is the dynamics between socio-economic changes, institutional changes, and the incentives for the use of political violence posed by the challenges reviewed above. There is much to learn from how these factors relate to exogenous factors such as changes in technology or in demographics (Dyson, 2012; Gat, 2005; Urdal, 2005), and how changes in one of them affect the others.


Thanks to Halvard Buhaug, Nils Petter Gleditsch, Idunn Kristiansen, Jack Levy, Naima Mouhleb, and JPR's reviewers for constructive comments to earlier versions of the manuscript. The research was funded by the Research Council of Norway, projects 217995/V10 and 204454/V10 (see for details).


Acemoglu, Daron & James A Robinson (2006) Economic Origins of Dictatorship and Democracy. New York: Cambridge University Press.

Angell, Norman (1910) The Great Illusion. London: Heinemann.

Babst, Dean V (1964) Elective governments - A force for peace. Wisconsin Sociologist 3(1): 9-14.

Bogaards, Matthijs (2010) Measures of democratization: From degree to type to war. Political Research Quarterly 63(2): 475-488.

Boix, Carles (2003) Democracy and Redistribution. Cambridge: Cambridge University Press.

Boix, Carles (2008) Economic roots of civil wars and revolutions in the contemporary world. World Politics 60(3): 390-437.

Boix, Carles (2011) Democracy, development, and the international system. American Political Science Review 105(4): 809-828.

Boix, Carles & Susan C Stokes (2003) Endogenous democratization. World Politics 55(4): 517-549.

Boix, Carles; Michael Miller & Sebastian Rosato (2013) A complete data set of political regimes, 1800-2007. Comparative Political Studies 46(12): 1523-1554.

Boswell, Terry & William J Dixon (1990) Dependency and rebellion. American Sociological Review 55(4): 540-559.

Bremer, Stuart A (1992) Dangerous dyads. Journal of Conflict Resolution 36(2): 309-341.

Brooks, Stephen G (1999) The globalization of production and the changing benefits of conquest. Journal of Conflict Resolution 43(5): 646-670.

Brown, Michael E; Owen R Coté Jr, Sean M Lynn-Jones & Steven E Miller, eds (2011) Do Democracies Win Their Wars? Cambridge, MA: MIT Press.

Bueno de Mesquita, Bruce; James D Morrow, Randolph M Siverson & Alastair Smith (1999) An institutional explanation of the democratic peace. American Political Science Review 93(4): 791-807.

Bueno de Mesquita, Bruce; Alastair Smith, Randolph M Siver-son & James D Morrow (2003) The Logic of Political Survival. Cambridge, MA: MIT Press.

Buhaug, Halvard (2006) Relative capability and rebel objective in civil war. Journal ofPeace Research 43(6): 691-708.

Carey, Sabine C (2006) The dynamic relationship between protest and repression. Political Research Quarterly 59(1): 1-11.

Carey, Sabine C (2007) Rebellion in Africa. Journal of Peace Research 44(1): 47-64.

Carey, Sabine C (2010) The use of repression as a response to domestic dissent. Political Studies 58(1): 167-186.

Cederman, Lars-Erik (2001) Back to Kant. American Political Science Review 93(4): 791-808.

Cederman, Lars-Erik; Kristian Skrede Gleditsch & Simon Hug (2013) Elections and ethnic civil war. Comparative Political Studies 46(3): 387-417.

Cederman, Lars-Erik; Simon Hug & Lutz F Krebs (2010) Democratization and civil war. Journal of Peace Research 47(4): 377-394.

Cederman, Lars-Erik; Andreas Wimmer & Brian Min (2010) Why do ethnic groups rebel? World Politics 62(1): 87-119.

Chan, Steve (1984) Mirror, mirror on the wall... Are the freer countries more pacific? Journal of Conflict Resolution 28(4): 617-648.

Choi, Seung-Whan (2010) Legislative constraints: A path to peace? Journal of Conflict Resolution 54(3): 438-470.

Choi, Seung-Whan (2011) Re-evaluating capitalist and democratic peace models. International Studies Quarterly 55(3): 759-769.

Colaresi, Michael & Sabine Carey (2008) To kill or to protect. Journal of Conflict Resolution 52(1): 39-67.

Collier, Paul & Anke Hoeffler (2004) Greed and grievance in civil war. Oxford Economic Papers 56(4): 563-595.

Collier, Paul & Dominic Rohner (2008) Democracy, development and conflict. Journal of the European Economic Association 6(1): 531-540.

Collier, Paul; Anke Hoeffler & Dominic Rohner (2009) Beyond greed and grievance. Oxford Economic Papers 61(1): 1-27.

Collier, Paul; Anke Hoeffler & Mans Soderbom (2004) On the duration of civil war. Journal of Peace Research 41(3): 253-273.

Collier, Paul; Anke Hoeffler & Mans Soderbom (2008) Post-conflict risks. Journal of Peace Research 45(4): 461-478.

Coppedge, Michael; John Gerring, David Altman, Michael Bernhard, Steven Fish, Allen Hicken, Matthew Kroenig, Staffan I Lindberg, Kelly McMann, Pamela Paxton, Holli A Semetko, Svend-Erik Skaaning, Jeffrey Staton & Jan Teorell (2011) Conceptualizing and measuring democracy: A new approach. Perspectives on Politics 9(2): 247-267.

Cranmer, Skyler J & Bruce A Desmarais (2011) Inferential network analysis with exponential random graph models. Political Analysis 19(1): 66-86.

Dafoe, Allan (2011) Statistical critiques of the democratic peace: Caveat emptor. American Journal ofPolitical Science 55(2): 247-262.

Dafoe, Allan; John R Oneal & Bruce M Russett (2013) The democratic peace: Weighing the evidence and cautious inference. International Studies Quarterly 57(1): 201-214.

Dahl, Robert A (1971) Polyarchy: Political Participation and Opposition. New Haven, CT: Yale University Press.

Davenport, Christian (2007a) State repression and political order. Annual Review of Political Science 10: 1-23.

Davenport, Christian (2007b) State Repression and the Domestic Democratic Peace. Cambridge: Cambridge University Press.

Davenport, Christian & David A Armstrong (2004) Democracy and the violation of human rights. American Journal of Political Science 48(3): 538-554.

Davies, James C (1962) Towards a theory of revolution. American Sociological Review 27(1): 5-19.

DeRouen, Karl & David Sobek (2004) The dynamics of civil war duration and outcome. Journal of Peace Research 41(3): 303-320.

Dorussen, Han & Hugh Ward (2010) Trade networks and the Kantian peace. Journal of Peace Research 47(1): 29-42.

Downes, Alexander B & Mary Lauren Lilley (2010) Overt peace, covert war? Security Studies 19(2): 266-306.

Downes, Alexander B & Todd S Sechser (2012) The illusion of democratic credibility. International Organization 66(3): 457-489.

Doyle, Michael W (1983) Kant, liberal legacies, and foreign affairs, part II. Philosophy & Public Affairs 12(4): 323-353.

Doyle, Michael W (1986) Liberalism and world politics. American Political Science Review 80(4): 1151-1169.

Dyson, Tim (2012) On demographic and democratic transitions. Population and Development Review 38(IS s1): 83-102.

Eck, Kristine & Lisa Hultman (2007) One-sided violence against civilians in war. Journal ofPeace Research 44(2): 233-246.

Elbadawi, Ibrahim A & Nicholas Sambanis (2002) How much war will we see? Journal of Conflict Resolution 46(3): 307-334.

Ember, Carol R; Melvin Ember & Bruce M Russett (1992) Peace between participatory polities. World Politics 44(4): 573-599.

Farber, Henry S & Joanne Gowa (1995) Polities and peace. International Security 20(2): 123-146.

Fearon, James D (1994) Domestic political audiences and the escalation of international disputes. American Political Science Review 88(3): 577-592.

Fearon, James D (1995) Rationalist explanations for war. International Organization 49(3): 379-414.

Fearon, James D (2004) Why do some civil wars last so much longer than others? Journal of Peace Research 41(3): 275-301.

Fearon, James D & David D Laitin (2003) Ethnicity, insurgency, and civil war. American Political Science Review 97(1): 75-90.

Fjelde, Hanne (2009) Buying peace? Oil wealth, corruption and civil war, 1985-99. Journal of Peace Research 47(2): 199-218.

Fjelde, Hanne (2010) Generals, dictators, and kings. Conflict Management and Peace Science 27(3): 195-218.

Fjelde, Hanne & Indra de Soysa (2009) Coercion, co-optation or cooperation? Conflict Management and Peace Science 26(1): 5-25.

Gartzke, Erik A (1998) Kant we all just get along? American Journal ofPolitical Science 42(1): 1-27.

Gartzke, Erik A (2000) Preferences and the democratic peace. International Studies Quarterly 44(2): 191-212.

Gartzke, Erik A (2007) The capitalist peace. American Journal of Political Science 51(1): 166-191.

Gartzke, Erik A & Kristian Skrede Gleditsch (2004) Why democracies may actually be less reliable allies. American Journal of Political Science 48(4): 775-795.

Gartzke, Erik A & J Joseph Hewitt (2010) International crises and the capitalist peace. International Interactions 36(2): 115-145.

Gartzke, Erik A & Alex Weisiger (2013) Permanent friends? Dynamic difference and the democratic peace. International Studies Quarterly 57(1): 171-185.

Gartzke, Erik A; Quan Li & Charles Boehmer (2001) Investing in the peace: Economic interdependence and international conflict. International Organization 55(2): 391-438.

Gat, Azar (2005) The democratic peace theory reframed. World Politics 58(1): 73-100.

Gat, Azar (2006) War in Human Civilization. Oxford: Oxford University Press.

Gates, Scott; Torbjorn L Knutsen & Jonathan W Moses (1996) Democracy and peace: A more skeptical view. Journal of Peace Research 33(1): 1-10.

Gates, Scott; Havard Hegre, Mark P Jones & Havard Strand (2006) Institutional inconsistency and political instability. American Journal of Political Science 50(4): 893-908.

Geis, Anna; Lothar Brock & Harald Muller, eds (2006) Democratic Wars. Basingstoke: Palgrave Macmillan.

Gibler, Douglas M (2007) Bordering on peace: Democracy, territorial issues, and conflict. International Studies Quarterly 51(3): 509-532.

Gibler, Douglas M & Jaroslav Tir (2010) Settled borders and regime type. American Journal of Political Science 54(4): 951-968.

Gleditsch, Kristian Skrede & Andrea Ruggeri (2010) Political opportunity structures, democracy, and civil war. Journal of Peace Research 47(3): 299-310.

Gleditsch, Kristian Skrede & Michael D Ward (2006) Diffusion and the international context of democratization. International Organization 60(4): 911-933.

Gleditsch, Nils Petter (1992) Democracy and peace. Journal of Peace Research 29(4): 369-376.

Gleditsch, Nils Petter & Havard Hegre (1997) Peace and democracy: Three levels of analysis. Journal ofConflict Resolution 41(2): 283-310.

Gleditsch, Nils Petter; Lene Siljeholm Christiansen & Havard Hegre (2007) Democratic jihad? Military intervention and democracy. World Bank Policy Research Working Paper no. 4242.

Gleditsch, Nils Petter; Havard Hegre & Havard Strand (2009) Democracy and civil war. In: Manus Midlarsky (ed.) Handbook of War Studies III. Ann Arbor, MI: University of Michigan Press, 155-192.

Gowa, Joanne (2011) The democratic peace after the Cold War. Economics & Politics 23(2): 153-171.

Gurr, Ted R (1968) A causal model of civil strife. American Political Science Review 62(4): 1104-1124.

Harrison, Ewan (2010) The democratic peace research program and system-level analysis. Journal of Peace Research

47(2): 155-165.

Hegre, Havard (2000) Development and the liberal peace. Journal of Peace Research 37(1): 5-30.

Hegre, Havard (2003) Disentangling democracy and development as determinants of armed conflict. World Bank Working Paper no. 24637 (http://siteresources.worldbank. org/DEC/Resources/disentangling_democracy_and_devel-opment.pdf).

Hegre, Havard (2008) Gravitating toward war. Journal of Conflict Resolution 52(4): 566-589.

Hegre, Havard & Havard Mokleiv Nygard (forthcoming) Governance and conflict relapse. Journal of Conflict Resolution.

Hegre, Havard; Tanja Ellingsen, Scott Gates & Nils Petter Gleditsch (2001) Toward a democratic civil peace? Democracy, political change, and civil war, 1816-1992. American Political Science Review 95(1): 33-48.

Huntley, Wade L (1996) Kant's third image: Systemic sources of the liberal peace. International Studies Quarterly 40(1): 45-76.

Huth, Paul K & Todd L Allee (2002) Domestic political accountability and the escalation and settlement of international disputes. Journal of Conflict Resolution 46(6): 754-790.

Jaggers, Keith & Ted R Gurr (1995) Transitions to democracy. Journal of Peace Research 32(4): 469-482.

James, Patrick; Eric Solberg & Murray Wolfson (1999) An identified systemic model of the democracy-peace nexus. Defence and Peace Economics 10(1):1-37.

Kadera, Kelly M; Mark JC Crescenzi & Megan L Shannon (2003) Democratic survival, peace, and war in the international system. American Journal of Political Science 47(2): 234-247.

Kalyvas, Stathis N & Laia Balcells (2010) International system and technologies of rebellion. American Political Science Review 104(3): 415-429.

Kant, Immanuel (1795/1991) Perpetual peace. In: Hans Reiss (ed.) Kant: Political Writings. Cambridge: Cambridge University Press, 93-130.

Kim, Hyung Min & David L Rousseau (2013) The reciprocal relationship between military conflict and democracy. Defence and Peace Economics 24(1): 47-72.

Kinsella, David (2005) No rest for the democratic peace. American Political Science Review 99(3): 453-457.

Lacina, Bethany (2006) Explaining the severity of civil war. Journal of Conflict Resolution 50(2): 276-289.

Layne, Christopher (1994) Kant or cant: The myth of the democratic peace. International Security 19(2): 5-49.

Leeds, Brett Ashley; Michaela Mattes & Jeremy S Vogel (2009) Interests, institutions, and the reliability of international commitments. American Journal of Political Science 53(2): 461-476.

Levy, Jack S (1989) The causes of war. In: Philip E Tetlock, Jo L Husbands, Robert Jervis, Paul C Stern & Charles Tilly (eds) Behavior, Society, and Nuclear War. New York: Oxford University Press, 209-313.

Levy, Jack S (2008) Preventive war and democratic politics. International Studies Quarterly 52(1): 1-24.

Lupu, Yonathan & Vincent A Traag (2013) Trading communities, the networked structure of international relations,

and the Kantian peace. Journal of Conflict Resolution 57(6): 1011-1042.

Lyall, Jason (2010) Do democracies make inferior counterin-surgents? Reassessing democracy's impact on war outcomes and duration. International Organization 64(1): 167-192.

Mansfield, Edward D & Jack Snyder (1995) Democratization and the danger of war. International Security 20(1): 5-38.

Maoz, Zeev (2006) Network polarization, network interdependence, and international conflict, 1816-2002. Journal of Peace Research 43(4): 391-411.

Maoz, Zeev & Bruce M Russett (1992) Alliance, contiguity, wealth, and political stability. International Interactions

18(3): 245-267.

Maoz, Zeev & Bruce M Russett (1993) Normative and structural causes of democratic peace, 1946-1986. American Political Science Review 87(3): 624-638.

Marshall, Monty G; Tedd R Gurr & Keith Jaggers (2013) Polity IV Project: Political Regime Characteristics and Transitions, 1800-2012. Dataset users' manual (http://

Mitchell, Sara McLaughlin (2002) A Kantian system? Democracy and third-party conflict resolution. American Journal of Political Science 46(4): 749-759.

Mitchell, Sara McLaughlin; Scott Gates & Havard Hegre (1999) Evolution in democracy-war dynamics. Journal of Conflict Resolution 43(6): 771-792.

Moore, Will H (1998) Repression and dissent: Substitution, context, and timing. American Journal of Political Science 42(3): 851-873.

Mousseau, Michael (2000) Market prosperity, democratic consolidation, and democratic peace. Journal of Conflict Resolution 44(4): 472-507.

Mousseau, Michael (2009) The social market roots of democratic peace. International Security 33(4): 52-86.

Mousseau, Michael & Yuhang Shi (1999) A test for reverse causality in the democratic peace relationship. Journal of Peace Research 36(6): 639-663.

Mousseau, Michael; Havard Hegre & John R Oneal (2003) How the wealth of nations conditions the liberal peace. European Journal of International Relations 9(2): 277-314.

Mukherjee, Bumba (2006) Does third party enforcement or domestic institutions promote enduring peace after civil wars? Foreign Policy Analysis 2(4): 405-430.

Muller, Edward N & Erich Weede (1990) Cross-national variations in political violence. Journal of Conflict Resolution

34(4): 624-651.

Narang, Vipin & Rebecca M Nelson (2009) Who are these belligerent democratizers? International Organization 63(2): 357-379.

Olson, Mancur (1993) Democracy, dictatorship and development. American Political Science Review 87(3): 567-576.

Oneal, John R & Bruce M Russett (1999) Is the liberal peace just an artifact of Cold War interests? International Interactions 25(3): 213-241.

Owen, John M (2005) Iraq and the democratic peace. Foreign Affairs 84(6): 122-127.

Park, Johann (2013) Forward to the future? The democratic peace after the Cold War. Conflict Management and Peace Science 30(2): 178-194.

Park, Johann & Michael Colaresi (forthcoming) Safe across the border. International Studies Quarterly.

Peceny, Mark (1999) Forcing them to be free. Political Research Quarterly 52(3): 549-582.

Peceny, Mark; Caroline C Beer & Shannon Sanchez-Terry (2002) Dictatorial peace? American Political Science Review 96(1): 15-26.

Pinker, Steven (2011) The Better Angels of Our Nature: Why Violence Has Declined. New York: Viking.

Prins, Brandon (2003) Institutional instability and the credibility of audience costs. Journal of Peace Research 40(1): 67-84.

Przeworski, Adam; Michael E Alvarez, José Antonio Cheibub & Fernando Limongi (2000) Democracy and Development: Political Institutions and Well-Being in the World, 1950-1990. Cambridge: Cambridge University Press.

Quinn, J Michael; T David Mason & Mehmet Gurses (2007) Sustaining the peace: Determinants of civil war recurrence. International Interactions 33(2): 167-193.

Raknerud, Arvid & Havard Hegre (1997) The hazard of war: Reassessing the evidence for the democratic peace. Journal ofPeace Research 33(4): 385-404.

Rasler, Karen & William R Thompson (2004) The democratic peace and a sequential, reciprocal, causal arrow hypothesis. Comparative Political Studies 37(8): 879-908.

Ray, James Lee (1993) Wars between democracies. International Interactions 18(3): 251-276.

Regan, Patrick M; Richard W Frank & David H Clark (2009) New datasets on political institutions and elections, 1972-2005. Conflict Management and Peace Science 26(3): 286-304.

Reiter, Dan (2001) Does peace nature democracy? Journal of Politics 63(3): 935-948.

Reiter, Dan & Allan C Stam (1998) Democracy, war initiation, and victory. American Political Science Review 92(2): 377-389.

Reuveny, Raphael & Quan Li (2003) The joint democracy-dyadic conflict nexus. International Studies Quarterly 47(3): 325-346.

Rosato, Sebastian (2003) The flawed logic of democratic peace theory. American Political Science Review 97(4): 585-602.

Rosecrance, Richard (1986) The Rise of the Trading State. New York: Basic Books.

Ross, Michael (2001) Does oil hinder democracy? World Politics 53(3): 325-361.

Rummel, Rudolph J (1983) Libertarianism and international violence. Journal of Conflict Resolution 27(1): 27-71.

Russett, Bruce M (1993) Grasping the Democratic Peace. Princeton, NJ: Princeton University Press.

Russett, Bruce (2005) Bushwhacking the democratic peace. International Studies Perspective 6(4): 395-408.

Russett, Bruce M (2009) Democracy, war and expansion through historical lenses. European Journal of International Relations 15(1): 9-36.

Russett, Bruce & John R Oneal (2001) Triangulating Peace: Democracy, Interdependence, and International Organizations. London: WW Norton.

Schultz, Kenneth A (1999) Do democratic institutions constrain or inform? International Organization 53(2): 233-266.

Schweller, Randall L (1992) Domestic structure and preventive war. World Politics 44(2): 235-269.

Small, Melvin & J David Singer (1976) The war-proneness of democratic regimes, 1816-1965. Jerusalem Journal of International Relations 1(4): 50-69.

Snyder, Jack (2000) From Voting to Violence: Democratization and Nationalist Conflict. New York: Norton.

Snyder, Jack & Erica D Borghard (2011) The cost of empty threats: A penny, not a pound. American Political Science Review 105(3): 437-456.

Snyder, Quddus Z (2013) The illiberal trading state. Journal of Peace Research 50(1): 33-45.

Thompson, William R (1996) Democracy and peace: Putting the cart before the horse? International Organization 50(1): 141-174.

Trachtenberg, Marc (2012) Audience costs: An historical analysis. Security Studies 21(1): 3-42.

Urdal, Henrik. 2005. People vs. Malthus: Population pressure, environmental degradation, and armed conflict revisited. Journal of Peace Research 42(4): 417-434.

Vreeland, James Raymond (2008) The effect of political regime on civil war. Journal of Conflict Resolution 52(3): 401-425.

Walter, Barbara (2004) Does conflict beget conflict? Explaining recurring civil war. Journal of Peace Research 41(3): 371-388.

Ward, Michael D & Kristian S Gleditsch (1998) Democratizing for peace. American Political Science Review 92(1): 51-62.

Weede, Erich (1984) Democracy and war involvement. Journal of Conflict Resolution 28(4): 649-664.

Weeks, Jessica L (2008) Autocratic audience costs: Regime type and signaling resolve. International Organization 62(1): 35-64.

Werner, Suzannne (2000) The effects of political similarity on the onset of militarized disputes, 1816-1985. Political Research Quarterly 53(2): 343-374.

Wright, Quincy (1965/1942) A Study of War, 2nd edn. Chicago, IL: University of Chicago Press.

HAVARD HEGRE, b. 1964, Dr Philos in Political Science (University of Oslo, 2004); Dag Hammarskjold Professor of Peace and Conflict Research, Uppsala University (2013- ); Research Professor, Peace Research Institute Oslo (2005- ); current research interests: democracy, development, and armed conflict; forecasting of armed conflict.

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