Armed conflicts are complex situations emerging out of a constellation of conditions (such as political, economic, historical and psychological conditions) and cannot be usually explained by reference to single causes. The economic motivations refer to all those material considerations and incentives that prompt collectivities to resort to the use of force for the attainment of their objectives. Economic motivations may range widely according to the type of conflict at hand, that is to say, whether a conflict transcends national boundaries (international vs. internal conflict) and whether its adversaries are state on non-state actors. In general, access to distant markets and scarce resources, imperialism, concerns about the impact of economic interdependence and population growth have been the most common economic causes of the outbreak of international wars, while the ‘greed’ and the exacerbation of ‘grievances’ are considered to be the main motivations for internal conflicts.
In the primitive times, tribes fought against each other in order to expand their hunting grounds and increase their procurement of food supply. In the early wars of history, great migratory movements resulted in contest for food and wealth among civilizations. In ancient Greece, Xenophon prompted the Greeks to attack the Persian Empire that was rich but weak. Thucydides famously explicated the Peloponnesian War in terms of uneven growth rates of wealth and power between Athens and Sparta. In addition, Plato explained in the Republic how population increase and competition among states for land caused the outbreak of war. And Democritus examined the damaging economic ramifications of wars (Robinson 1900, 588-591, Mills 2002, 42). The ascent of the Roman Empire was based on the conquest of provinces that constantly provided slaves, revenues and material wealth to Rome. In the Middle Ages, all types of wars were to a certain extent economically motivated including the crusades that, by right, were bringing all riches of ‘infidels’ to Christians. Furthermore, the Napoleonic wars – and many of those that followed it –were about the acquisition of trade or trade routes and have been categorized as commercial wars. Therefore, as Edward Van Dyke Robinson (1900) remarked in the turn of the 20th century, the principal cause of all wars has been economic. The political and economic sciences are the main venues where the economic motivations of armed conflict have been discussed. Nevertheless, until recently, war studies have mainly focused on the occurrence of the phenomenon in the Western world, or explained global developments from a Western perspective. Research on wars has additionally been incomplete as it has been overwhelmingly concerned with the outbreak of international wars and, more specifically, systemic wars. In this respect, Mercantilism, Liberalism, Marxism, and Political Realism have provided the most influential accounts of the economic causes of war. Indeed, most of this scholarship focuses on the impact of trade on war, that is to say, whether economic interdependence and trade relations diminish or increase the probability of interstate war. The mercantilist thought was prevalent in Europe from the 16th to the 18th century. Its appearance accompanied and facilitated the centralization of power in the European states. Its supporters included businessmen, politicians and professors and its content ranged from one country to another (Coulomb 2004, 13-15). This fact prompted Harry G. Johnson (1974, 3) to claim that mercantilism ‘was a collection of often mutually contradictory ideas expressed with varying degrees of clarity by men of widely varying levels of intelligence and reasoning power’. Overall, mercantilists viewed international economic relations as a zero-sum game: each country’s gains were at the expense of another. As a result, they suggested that the interest of states is associated with the acquisition by all means – i.e., including the use of coercion – of monopoly control of resources and foreign markers (Anderton 2003, 211). While some mercantilists (e.g. Antoine de Montchrestien) advocated that their country should reach autarchy, others (e.g. Francis Bacon and Simon Clément) suggested the expansion of exports and the diminution of imports (Coulomb 2004, 19-21). The common tenet of different mercantilists was a belief in the importance of positive trade balances for the accomplishment of political objectives and the financing of wars. Mercantilism was accused of having stimulated nationalism and xenophobia as well as of providing justification for the commercial wars of its time (Coulomb 2004). In response to the mercantilists, liberals have advocated the pacifying effect of trade and economic relations since the second half of the 18th century. Montesquieu wrote in The Spirit of the Laws (1989, 338) that commerce:
‘polishes and softens barbarous mores […] The natural effect of commerce is to lead to peace. Two nations that trade with each other become reciprocally dependent; if one has an interest in buying, the other has an interest in selling, and all unions are founded on mutual needs.’
Adam Smith denounced in The Wealth of Nations (2007, 314) the mercantilist line of argument concerning the benefit of favorable trade balances as absurd. He claimed that it made good sense to import commodities whose domestic production cost was much higher (Smith 2007, 294-295). Economic interdependence and free trade generated benefits for countries and their citizens that they would not easily put in peril by initiating a war. Smith also challenged the mercantilist belief in the advantages of colonization. He argued that the maintenance of colonies weakened mother countries because it required the allocation of substantial military resources (Smith 2007, 383). The positive impact of trade on interstate peace was also extensively analyzed by Tom Paine in Common Sense (1995) and Rights of Man (1995). Paine (1995, 265-266) noticed that commerce:
‘…is a pacific system, operating to cordialize mankind, by rendering nations, as well as individuals, useful to each other. [...]If commerce were permitted to act to the universal extent it is capable, it would extirpate the system of war, and produce a revolution in the uncivilized state of governments.’
Jeremy Bentham expressed similar views about the benefits of free trade and remarked that the emancipation of colonies would remove a cause of jealousy and animosity among European states. Bentham asserted that decolonization would render the outbreak of war among European countries less likely for an extra reason: Europeans would henceforth have to fight each other on their own territories (Conway 1989, 96-97). Overall, several liberals such as John Stuart Mill, Richard Cobden and Frédéric Bastiat endorsed in the mid-19th century the assumption that the devastating consequences of armed conflicts outweighed any expected benefits out of them and expressed their belief in the contribution of the expansion of free trade to the consolidation of peace. However, the Franco-Prussian war in 1870, the deterioration of relations among several great powers in the 1880s (for instance, between Austria and Russia and between Britain and Russia), and the economic recession of that time that gave rise to protectionist policies undermined confidence in the liberal reasoning. Although Norman Angell argued in the beginning of the 20th century about the disutility of wars and predicted the diminished ferocity of future warfare (Navari 1989, 341), the outbreak of the First World War blew much of the credibility of the liberal thesis. Furthermore, the ascendancy of mercantilism during the 1930s, the eruption of the Second World War, and the Cold War rivalry hindered for several decades the development of the free trade theory. The importance of subsistence as a motivation for conflict in world history was stressed by Thomas Malthus in An Essay on the Principle of Population (1998). The Malthusian theory illuminated the causal relationship between population growth, scarcity of resources, and conflict outbreak. This argument was borrowed in the early 1970s by Nazli Choucri and Robert C. North (1972) who added, in the population growth–conflict relationship, the factor of technological growth that increases a state’s reliance on access to resources. The liberal arguments have been criticized by Marxist analysts. Karl Marx did not himself develop a theory of war; nor was he preoccupied with international politics. His analysis focused mainly on domestic politics and the conflict among classes in the capitalist period (Levy and Thompson 2010, 86, Coulomb 2004, 114). Marx anticipated that the most important and final war would be the struggle of classes. This war would bring about the replacement of capitalism by communism. It would also end all antagonisms and conflicts among peoples. Marx and Engels dismissed free trade as a policy aiming to serve the bourgeoisie’s interests. Commerce provided a temporary remedy to the capitalist countries’ problem of falling profit rates. Nevertheless, Marx predicted that free trade would transfer capitalism’s internal contradictions to the international level and, as a result, it would precipitate capitalism’s downfall (Coulomb 2004, 118-120). With respect to colonization, Marx’s work included specific references to the cases of Ireland, India and China. His acknowledgement of the contribution of British policies to the modernization of India was viewed as embarrassing by his followers who wanted to associate Marxism with support to self-determination (Brewer 1990, 54-56). However, one should read his analysis within the context of his general consideration of capitalism as an essential stage towards socialism (Wolfe 1997, 389). Notwithstanding that Marx never used the term imperialism, Patrick Wolfe (1997, 389) remarked that ‘the majority of theorists of imperialism have claimed to be furthering his ideas’. Equally interesting is the fact that the Marxist debate on imperialism has been largely shaped by a liberal work, precisely, John A. Hobson’s, Imperialism: A Study (2006). Hobson explained imperialism in terms of under-consumption in capitalist countries. In particular, industrialists acquired monopoly positions in their countries and were able to determine prices. As a result, they were making important capital savings that outstripped investment opportunities in their domestic economy. Capitalists, subsequently, needed to direct capital investments and excessive productions to new markets. Considering that colonial powers enforced protectionist regimes in regions under their control, capitalist countries should find non-appropriated areas for their surpluses of production and savings. Hobson asserted that imperialism favored militarism and predicted that the emergence of new industrial countries might have as consequence the outbreak of a war for the redistribution of territories (Etherington 1982, 23). Rudolf Hilferding provided in Finance Capital (1981) the first Marxist account of imperialism. Hilferding (1981, 21) supported that a new stage of capitalism had emerged, having as main feature the concentration and ‘intimate relationship’ of banking and industrial capital in the form of finance capital. The latter sought domination in the domestic economy with the establishment of monopolies. Finance capital also pursued an aggressive policy of capital export even in other industrialized countries. It also exercised pressure on states not only to protect with tariffs the preservation of its position in the domestic market, but also expand the size of the national market, if necessary, even with the use of force (Hilferding 1981, 334-335). Hilferding (1981, 366-367) argued that war avoidance required the resistance of the proletariat and the middle class. Nonetheless, he did not rule out the possibility that the largest firms might in the long run reach an ‘industry-wide agreement’ for the preservation of their interests (Hilferding 1981, 360-361). In 1914, after the outbreak of the First World War, Karl Kautsky wrote that, as a rule, industrial zones dominated over agrarian zones. Capitalist states maintained interest in extending the agrarian zones with which they maintained trade relations. As a result, imperialist states have entered into fierce competition for the control of agrarian zones and this competition escalated into a dangerous arms race and the outbreak of the First World War. Kautsky ( 1970, 46) supported that the outcome of war could be a new phase of capitalism, so-called ‘ultra-imperialism’, in which the strongest imperialist states might agree to denounce arms races and form a political cartel to jointly dominate over agrarian areas. Altogether, Kautsky followed Hilferding’s prognosis about the possible peaceful evolution of capitalism but did not also endorse his analysis concerning the prevalence of banking over industrial capital. Rosa Luxemburg provided another influential Marxist approach to imperialism and stressed that, capitalism needed to expand in pre-capitalist areas in order to generate ‘surplus value’. In this regard, the aim of imperialism was ‘to establish the exclusive and universal domination of capitalist production in all countries and for all branches of industry’ (Luxemburg 2003, 397). However, imperialism was not going to produce the expected result: it would even contribute to the end of capitalism. This is because capitalism suffered from the ‘disease’ of militarism that would cause the outbreak of war ‘in spite of the complete indecisiveness of the objectives and motives of the conflict’ (Luxemburg 1999, chapter 4). Luxemburg claimed that the imperial phase commenced with the eruption of a sequence of wars in the end of the 19th century. Imperialism’s distinguishing feature was the retraction of the industrial countries’ struggle from the periphery to their own territory in Europe. Hence, Luxemburg depicted the First World War as a struggle for territorial redistribution of the world among the leading capitalist countries (Etherington 1982, 11-12). The most renowned approach to imperialism was articulated by Vladimir Lenin in Imperialism: The Highest Stage of Capitalism (1966). Yet, contrary to public perception, Lenin’s work was of limited theoretical originality (Brewer 1990, 116, Winslow 1931, 730). It integrated and reproduced many findings of his predecessors (for instance Hilferding’s argument on finance capital and capital export, and Bukharin’s view of imperialism as a particular stage of development). Indeed, Lenin has been chiefly credited with lending to the Marxist approach of imperialism ‘dogmatic coherence and much of its eventual influence’ (Fieldhouse 1961, 192). As Lenin himself admitted, Imperialism: The Highest Stage of Capitalism devoted special attention to a criticism of ‘Kautskyism’. Lenin branded Kautsky and Hilferding as ‘ex-Marxists’ who renounced the revolutionary principles of Marxism. This is because they believed that a peaceful stage of capitalism could emerge. Lenin depicted ultra-imperialism as ‘ultra-nonsense’ (1966, 87) and asserted that there could be no peace among the imperialist powers but only a truce between periods of wars (1966, 111). Therefore, early 20th century Marxists were divided on their predictions about the outcome of imperialism and the future direction of capitalism. The Marxist-Leninist imperialist theory was criticized by liberals and political realists alike for its determinism, its confinement to the capitalist period, and its focus on a particular type of warfare. Furthermore, the Marxist theory did not offer a proper account of the major war of its time (i.e., the First World War) in which the rival colonial powers ended up fighting on the same side (Levy and Thompson 2010, 89-91). The Cold War Marxist thought (i.e., Paul Baran and the dependency theorists) took a turn away from the study of imperialism’s militarism and concentrated on the problem of Third World underdevelopment in the context of decolonization. Echoing many mercantilist views, political realists have highlighted since the 1940s the trade’s potential to cause economic competition and rivalries. In 1939, Carr wrote in The Twenty Years’ Crisis that free trade did not generate equal gains for all countries owing to the market’s imperfections. States accruing fewer benefits might get suspicious and fearful of the motives and intentions of the most advantaged ones from trade. Hence, the former might resort to war against the latter in order to restore equality of distribution of gains (Carr 2001, 42-61). According to Kenneth Waltz, economic interdependence may even increase the prospect of armed conflict. In his own words, ‘It is impossible to get a war going unless the potential participants are somehow linked’ (Waltz 1979, 138). Moreover, Waltz claimed that states worry about the extent of their dependence on external suppliers. States perceive dependence on others as a source of vulnerability and ‘[l]ike other organizations, states seek to control what they depend on or to lessen the extent of their dependency’ (Waltz 1979, 106). John J. Mearsheimer (1990, 45) advanced Waltz’s reasoning and added that the fear of states is that, in a case of crisis or war, adversaries might blackmail them or discontinue the flow of suppliers. And Barry Buzan (1984, 623) concluded that it was security considerations rather than the international economic structure itself that played major role in the decision of countries to go to war. Overall, during the Cold War period, the warfare literature was overwhelmingly preoccupied with the spectrum of a strategic war and dealt with the questions of nuclear deterrence, arms control and disarmament rather than the study of the economic causes of conflict.  For a discussion of the influence of Richard Cobden’s work on J. A. Hobson see Cain (1978).
The end of bipolarity was followed by a renewed interest of the political and economic sciences in the economic motivations for armed conflict. One strand of the literature concerns the revival of the realist-liberal debate on the pacifying effect of trade and economic interdependence. This time the discussion is stimulated by two factors. The first is the advancement of international conditions of globalization. The second is the burgeoning of empirical studies that utilize quantitative research methods to analyze large datasets. Interestingly, while many of these studies (for instance, Oneal et al. 1996, Oneal and Russett 1999, and Maoz 2009) affirm the liberal thesis that trade has a pacifying influence on ‘war-prone’ relations among states, others (such as Beck et al. 1998) remark that trade does not inhibit the outbreak of war. From a realist perspective, Gowa and Mansfield (1993) assert that the decision of countries to open their markets is influenced by power politics and, as a result, free trade is more likely to be established within, rather than across, political-military alliances. Pevehouse (2004) claims that each side of the debate illuminates only a part of the story. His empirical investigation shows that trade may both increase the probability of conflict and, at the same moment, restrain the frequency of that conflict. Similarly, Copeland (1996) argues (though without the use of quantitative methods) for the need to fuse the liberal insights on the benefits of economic interdependence with the realist concerns about the possible costs of such a relationship into a new theoretical framework. The latter will use the expectations of future trade as a causal variable for the analysis of the outbreak of war. Furthermore, Gartzke et al. (2001) assert that economic interdependence generates multiple channels of interactions and increases the ‘vocabulary’ available to states to credibly communicate their resolve without going to war. According to Gartzke and Li (2003, 569-570), globalization promotes peace for two more reasons. First, whereas the economic opportunity costs of conflictual behavior are quantifiable, the valuation of political goals is not equally possible. Second, globalization has increased the ability of market agents to react to political risk. For instance, frightened investors may flee risky markets and the borrowing cost of these countries may increase. Altogether, Gartzke and Li (2003, 583) argue that ‘the interaction of states and markets is capable of providing positive political externalities’. In a similar vein, Blanton and Apodaca (2007) present the global market as an ‘audience’ that rewards or punishes states for their policies. They conclude that although the global market mat not prevent the outbreak of intrastate conflicts, it increases the incentives for the quick resolution of these conflicts. And Elbadawi and Hegre (2008) support that globalization indirectly diminishes the risk of conflict through the stimulation of short- and long-term growth. On the other hand, Murshed (2010, 205) asserts that globalization may promote conflict by increasing inequalities between and within countries. Likewise, Barbieri (1996 and 2002) remarks that extensive economic interdependence increases the likelihood of countries engaging in war. Another strand of the contemporary literature concentrates on the incidence of internal conflicts and problematizes new questions such as the motivations of individual belligerents to fight. The discussion has indeed been framed by the ‘greed-and-grievance’ debate since the late 1990s. The ‘greed’ argument has been developed by economic theorists who view the occurrence of internal war as the outcome of rational calculations in terms of costs and opportunities. According to Paul Collier and Anke Hoeffler (1998, 567), the probability and duration of civil wars are a function of the gains from rebellion, made up of the probability of rebel victory and the gains from victory (state capture or secession), and the costs of rebellion, made up of the opportunity costs of conflict and the cost of coordination. The outbreak of a civil war is explained by the case-specific circumstances that generate profitable opportunities for rebels. The Collier-Hoeffler model suggests that there are three types of opportunities. The first refers to the opportunities of financing rebellion. The possession of exportable primary commodities is considered to be the most effective form of financing a conflict because it renders the entire activity privately profitable and it resolves the collective action problem. The second type of opportunities is related to the cost of rebellion and the decision of recruits to forego their incomes and enlist. It is associated with the lack of alternative economic opportunities and its main proxies are: the size of per capita income, male secondary school enrollment, and the growth rate of the economy and the population. Statistical evidence leads proponents of the ‘greed’ model to the conclusion that the lower are the per capita income, the male education level and the economy’s growth rate, the greater is the opportunity of belligerents to rebel because they do not have much to lose. Likewise, it is found that the population growth rate impacts on the tightness of the labor market and the extent of economic opportunities and, thus, on the decision to rebel. Finally, the third type of opportunities relates to the probability of winning the war. It is about a state’s capacity to defend itself and the rebels’ access to military power (Collier and Hoeffler 2004). Altogether, Collier and Hoeffler argue that civil war is more the result of predatory behavior by rebel groups seeking control over lootable resources (greed) than the outcome of political, ethnic or religious grievances. This happens because it is eventually the financial viability of rebellion that determines the risk of conflict. Indeed, Collier (2000) contents that ethnic grievances are actively manufactured by rebel organizations in order to motivate their forces and create the essential divisions in the societies. The ‘greed’ thesis is criticized of simplistically grouping all civil wars in the same category as well as, promoting a bias against rebel groups without even questioning the role of state in the outbreak of political violence (Humphreys 2003, 4, Lemarchand 2009, 42). Moreover, the Collier-Hoeffler model fails to explain the protraction of conflicts in more developed regions (e.g. Northern Ireland) and the burgeoning of the child soldier phenomenon. It does not also do any justice to the political struggle and motives of people such as Nelson Mandela (Herbst 2000, 279-282). From a political science perspective, critics of the ‘greed’ model propose an alternative framework centered on the idea that internal conflict is motivated by ‘grievances’. This approach is based on the concept of ‘relative deprivation’ that was originally advanced in the early 1970s by Ted Robert Gurr (1970, 128) to describe the widespread perception of discrepancies between the goals of human action and the prospects of attaining those goals. Relative deprivation may lead to the outbreak of civil conflict, especially when it is related to the existence of ‘horizontal’ inequalities (i.e., inequalities between groups defined by region/ethnicity/class/religion) in terms of socio-economic conditions, access to power and protection of collective rights (Stewart 2000, 23). The most common causes of perceptions of relative deprivation are: economic stagnation or decline, narrow development (i.e., uneven development that exacerbates existing horizontal inequalities), structural adjustment programs with negative social impact, predatory state rule and environmental scarcities. Overall, contrary to the ‘greed’ argument, the ‘grievance’ thesis highlights the role of political and identity motivations for conflict. It claims that grievances often result from policies of ethnic discrimination in the domains of education and employment and under-representation in governance. Collier et al. (2009, 2) have taken into consideration the criticism of their earlier work and state that their ‘own thinking on proneness to civil war has also evolved’. Nevertheless, their belief that the decisive factor for the risk of rebellion is ‘feasibility rather than motivation’ has not changed (Collier et al. 2009, 23). What is new in their analysis, is the refinement and enrichment of the measurement of feasibility with the addition to their previous indicators (level, growth and structure of income) of three new non-economic variables, precisely: having formed part of the French security umbrella (as a former colony), proportion of male population between 15-29 years old, and proportion of mountainous terrain of the country in question. Altogether, Collier et al. (2009, 24) conclude that their original hypothesis is still valid and ‘where rebellion is feasible it will occur’. Finally, some analysts see no reason why greed and grievance should be presented in antagonistic ‘either-or’ terms for the explanation of the causes of intrastate conflicts. For instance, Querido (2009) notices that both natural resources (such as diamonds and oil) and ethnic divisions may prompt a government to exercise violence against its civilians. Similarly, Murshed and Tadjoeddin (2009, 102) argue that the greed and grievance approaches may be viewed as complementary owing to the fact that ‘greed may lead to grievances and vice versa’.  The first of this type of studies indeed appeared during the 1980s. See Polachek (1980) and Gasiorowski (1986).
A great part of the original realist-liberal debate on the impact of trade on war revolved around the analysis of the two World Wars. For instance, while the realists remarked that the unprecedented levels of economic interdependence among the Europeans of the early 20th century did not prevent the First World War, the liberals countered that the economic protectionist policies of the 1930s contributed to the outbreak of the Second World War. However, the realist-liberal discussion has recently moved from the causes of specific conflicts to methodological questions concerning the processing and analysis of large datasets with dozens of case studies. On the contrary, with respect to the greed and grievance debate, the discussion has not become so overtly technical and abstract. Several papers keep discussing the causes of intrastate wars through the analysis of specific case studies. The civil war in Sierra Leone is cited as the most paradigmatic case of armed conflict that has been motivated by greed. This happens because the ‘Revolutionary United Front’ (RUF) waged operations against the state forces for the control of the diamond-rich areas. Not only did both the RUF and the government sell future exploitation rights to finance their war, but also rebels and government officials engaged in extensive looting operations out of which they earned large sums of money. Indeed, it is the magnitude of these earnings that prompts many analysts to claim that, unfortunately, those who had the power to end the war, were the ones who benefited most from its conduct (Davies 2000). On the other hand, an exemplary demonstration of the grievance argument is the civil conflict in Nepal between the Maoist guerrillas and the state. The Maoists associated their struggle with their poverty, landlessness, social and political exclusion and the state officials’ predatory behavior. As Deraniyagala (2005) explains, Nepal is characterized by large horizontal inequalities in terms of poverty and human development (i.e., differences by geographical location, caste and ethnicity and rural-urban disparities) that have been aggravated since the early 1990s by the introduction of a structural adjustment program aiming at economic liberalization. Finally, Benedikt Korf (2005, 201-212) points to the case of Sri Lanka to argue that greed and grievance are causally linked and reinforced factors. In particular, Korf supports that the political economy of war produces a self-sustaining logic of clientelism along the ‘friends-foes’ dividing lines that nourishes grievance discourses along the same lines. These grievances, in turn, motivate people to fight for ‘justice’ and, thus, they offer economic opportunities for greedy conflict entrepreneurs.
Anderton, Charles H. 2003. Economic Theorizing of Conflict: Historical Contributions, Future Possibilities. Defence and Peace Economics 14, no. 3: 209-222. Barbieri, Katherine. 1996. Economic Interdependence: A Path to Peace or a Source of Interstate Conflict? Journal of Peace Research 33, no. 1: 29-49. Barbieri, Katherine. 2002. The Liberal Illusion: Does Trade Promote Peace? Ann Arbor, Michigan: University of Michigan Press. Beck, Nathaniel, Jonathan N. Katz and Richard Tucker. 1998. Taking Time Seriously: Time-Series-Cross-Section Analysis with a Binary Dependent Variable. American Journal of Political Science 42, no. 4: 1260-1288. Blanton, Robert G. and Clair Apodaca. 2007. Economic Globalization and Violent Civil Conflict: Is Openness a Pathway to Peace? The Social Science Journal 44, no. 4: 599-619. Brewer, Anthony. 1990. Marxist Theories of Imperialism: A Critical Survey. 2nd Ed. London: Routledge. Buzan, Barry. 1984. Economic Structure and International Security: The Limits of the Liberal Case International Organization 38, no. 4: 597-624. Cain, P. J. 1978. J. A. Hobson, Cobdenism, and the Radical Theory of Economic Imperialism, 1898-1914. The Economic History Review 31, no. 4: 565-584. Carr, Edward Hallett. 2001. Twenty Years' Crisis, 1919-1939: An Introduction to the Study of International Relations. Hampshire: Palgrave Macmillan. Choucri, Nazli and Robert C. North. 1972. Dynamics of International Conflict: Some Policy Implications of Population, Resources, and Technology. World Politics 24: 80-122. Collier, Paul. 2000. Economic Causes of Civil Conflict and their Implications for Policy. Washington DC: The World Bank. Collier, Paul and Anke Hoeffler. 1998. On Economic Causes of Civil War. Oxford Economic Papers 50, no. 4: 563-573. Collier, Paul and Anke Hoeffler. 2004. Greed and Grievance in Civil War. Oxford Economic Papers 56, no. 4: 563-595. Collier, Paul, Anke Hoeffler and Dominic Rohner. 2009. Beyond Greed and Grievance: Feasibility and Civil War. Oxford Economic Papers 61, no. 1: 1-27. Conway, Stephen. 1989. Bentham on Peace and War. Utilitas 1, no. 1: 82-101. Copeland, Dale C. 1996. Economic Interdependence and War: A Theory of Trade Expectations. International Security 20, no.4: 5-41. Coulomb, Fanny. 2004. Economic Theories of Peace and War. London: Routledge. Davies, Victor A.B. 2000. Sierra Leone: Ironic Tragedy. Journal of African Economies 9, no. 3: 349-369. Deraniyagala, Sonali. 2005. The Political Economy of Civil Conflict in Nepal. Oxford Development Studies 33, no. 1: 47-62. Elbadawi, Ibrahim and Håvard Hegre. 2008, Globalization, Economic Shocks, and Internal Armed Conflict. Defence and Peace Economics 19, no. 1: 37-60. Etherington, Norman. 1982. Reconsidering Theories of Imperialism. History and Theory 21, no. 1: 1-36. Fieldhouse, D. K. 1961. ‘Imperialism’: An Historiographical Revision. The Economic History Review 14, no. 2: 187-209. Gartzke, Erik, Quan Li and Charles Boehmer. 2001. Investing in the Peace: Economic Interdependence and International Conflict. International Organization 55, no. 2: 391-438. Gartzke, Erik and Quan Li. 2003. War, Peace, and the Invisible Hand: Positive Political Externalities of Economic Globalization. International Studies Quarterly 47, no. 4: 561-586. Gasiorowski, Mark J. 1986. Economic Interdependence and International Conflict: Some Cross-National Evidence. International Studies Quarterly 30, no. 1: 23-38. Gowa, Joanne and Edward D. Mansfield. 1993. Power Politics and International Trade. The American Political Science Review 87, no. 2: 408-420. Gurr, Ted Robert. 1970. Sources of Rebellion in Western Societies: Some Quantitative Evidence. Annals of the American Academy of Political and Social Science 391: 128-144. Herbst, Jeffrey. 2000. Economic Incentives, Natural Resources and Conflict in Africa. Journal of African Economies 9, no. 3: 270-294. Hilferding, Rudolf. 1981. Finance Capital: A Study of the Latest Phase of Capitalist Development. Trans. Morris Watnick and Sam Gordon, London: Routledge & Kegan Paul. Hobson, John A. 2006. Imperialism: A Study. Marxists’ Internet Archive. http://www.marxists.org/archive/hobson/1902/imperialism/index.htm. Humphreys, Macartan. 2003. Economics and Violent Conflict. Cambridge, MA: Harvard School of Public Health, Conflict Prevention Initiative, Program on Humanitarian Policy and Conflict Research. Johnson, Harry G. 1974. Mercantilism: Past, Present and Future. The Manchester School 41, no. 1: 1-17. Kautsky, Karl. 1970. Ultra-imperialism. New Left Review 59: 41-46. Korf, Benedikt. 2005. Rethinking the Greed–Grievance Nexus: Property Rights and the Political Economy of War in Sri Lanka. Journal of Peace Research 42, no. 2: 201-217. Lemarchand, René. 2009. The Dynamics of Violence in Central Africa. Philadelphia: University of Pennsylvania Press, 2009. Lenin, Vladimir I. 1966. Imperialism: The Highest Stage of Capitalism. 13th ed. Moscow: Progress Publishers. Levy, Jack S. and Thompson, William, R. 2010. Causes of War. West Sussex: Wiley-Blackwell. Luxemburg, Rosa. 1999. Reform of Revolution. Rosa Luxemburg Internet Archive. http://www.marxists.org/archive/luxemburg/1900/reform-revolution/index.htm. Luxemburg, Rosa. 2003. The Accumulation of Capital. Trans. Agnes Schwarzschild, London: Routledge. Malthus, Thomas 1998. An Essay on the Principle of Population. Electronic Scholarly Publishing Project. http://www.esp.org/books/malthus/population/malthus.pdf Maoz, Zeev. 2009. The Effects of Strategic and Economic Interdependence on International Conflict Across Levels of Analysis. American Journal of Political Science 53, no. 1: 223-240. Mearsheimer, John J. 1990. Back to the Future: Instability in Europe after the Cold War. International Security 15, no. 1: 5-56. Mills, John. 2002. A Critical History of Economics. Hampshire: Palgrave Macmillan. Montesquieu, Charles de Secondat. 1989. The Spirit of the Laws. Trans. Anne M. Cohler, Basia Carolyn Miller and Harold Samuel Stone, Cambridge: Cambridge University Press. Murshed, Syed Mansoob. 2010. Explaining Civil War: A Rational Choice Approach Cheltenham, UK: Edward Elgar. Murshed, Syed Mansoob and Mohammad Zulfan Tadjoeddin. 2009. Revisiting the Greed and Grievance Explanations for Violent Internal Conflict. Journal of International Development 21, no. 1: 87-111. Navari, Cornelia. 1989. The Great Illusion Revisited: The International Theory of Norman Angell. Review of International Studies 15, no. 4: 341-358. Oneal, John R., Frances H. Oneal, Zeev Maoz and Bruce Russett. 1996. The Liberal Peace: Interdependence, Democracy, and International Conflict, 1950-85. Journal of Peace Research 33, no. 1: 11-28. Oneal, John R. and Bruce Russett. 1999. Assessing the Liberal Peace with Alternative Specifications: Trade Still Reduces Conflict. Journal of Peace Research 36, no. 4: 423-442. Paine, Thomas. [1776 and 1792]1995. Rights of Man, Common Sense, and Other Writings. Ed. Mark Philp, Oxford: Oxford University Press. Pevehouse, Jon C. 2004. Interdependence Theory and the Measurement of International Conflict. The Journal of Politics 66, no. 1: 247-266. Polachek, Solomon William. 1980. Conflict and Trade. Journal of Conflict Resolution 24, no. 1: 55-78. Querido, Chyanda M. 2009. State-Sponsored Mass Killing in African Wars – Greed or Grievance? International Advances in Economic Research 15, no. 3: 351-361. Robinson, Edward Van Dyke. 1900. War and Economics in History and in Theory. Political Science Quarterly 15, no. 4: 581-628. Smith, Adam. 2007. An Inquiry into the Nature and Causes of the Wealth of Nations. Hampshire: Harriman House Ltd. Stewart, Frances. 2000. The Root Causes of Humanitarian Emergencies. In War, Hunger, and Displacement: The Origins of Humanitarian Emergencies, ed. E. Wayne Nafziger, Frances Stewart and Raimo Väyrynen, 1-42. Oxford: Oxford University Press, UNU/WIDER Studies in Development Economics, 1. Waltz, Kenneth. 1979. Theory of International Politics. Reading: Addison-Wesley. Winslow, E. M. 1931. Marxian, Liberal, and Sociological Theories of Imperialism. The Journal of Political Economy 39, no. 6: 713-758. Wolfe, Patrick. 1997. History and Imperialism: A Century of Theory, from Marx to Postcolonialism. The American Historical Review 102, no. 2: 388-420.