Democratic Peace or Liberal Peace: The Debate

REVIEW BY PHILIP A. SCHRODT

Department of Political Science, University of Kansas

Globalization and Armed Conflict. Edited by Gerald Schneider, Katherine Barbieri, andNils Petter Gleditsch. Lanham, MD: Rowman and Littlefield, 2003. 384 pp., $75.00 cloth(ISBN: 0-7425-1831-0), $32.95 paper (ISBN: 0-7425-1832-9).

Over the past two decades, the ‘‘democratic peace’’ hypothesisFnamely, that warsdo not occur between democraciesFhas received a great deal of attention; JamesRay (1995) and Steve Chan (1997) provide thorough reviews of this literature.Closely relatedFin fact one of the strongest candidates for an alternative expla-nationFis the ‘‘liberal peace’’ hypothesis, which posits that economic developmentand mutual trade are powerful inhibitors of war (see, for example, Keohane andNye 1977; Russett and Oneal 2001). Both of these hypotheses have distinguishedpedigrees in qualitative liberal political theory and can be traced to the beginningsof the nineteenth century. Both hypotheses are sufficiently simple that they havebeen invoked in public policy debates. New York Times columnist Thomas Friedman,for example, reformulated the liberal peace hypothesis in 1996 in the followingterms: ‘‘Countries that both have McDonald’s restaurants don’t fight each other.’’Both hypotheses have been used to explain the transition from the fratricidalWestern Europe of the first half of the twentieth century to Europe’s present statusas a zone of peace.

The empirical support for the two hypotheses, however, is quite different. Ev-idence for the democratic peace is so strong that arguments against it requiremethodologically esoteric appeals to alliance linkages, control variables, and ex-pected conflict frequencies under a null hypothesis. The liberal peace, in con-trast, suffers from two very conspicuous and large-scale failures: World War I andWorld War II. Those empirical challenges continue to the present. Friedman’s‘‘McDonald’s hypothesis,’’ for example, lasted only three years before the UnitedStates began bombing attacks on the Serbian capital of Belgrade, a city with sevenMcDonald’s restaurants. In short, whereas the practical burden of proof for thedemocratic peace involves showing that it is false, the burden of proof on the liberalpeace involves showing that it is true.

The theoretical and methodological debate over the liberal peace hypothesis isthe focus of Globalization and Armed Conflict, edited by Gerald Schneider, KatherineBarbieri, and Nils Petter Gleditsch. The book is the result of a series of interactions,including workshops at the International Studies Association in 1998 and in Co-penhagen in 2000, as well as a special issue of the Journal of Peace Research. Most ofthe contributors are familiar names in the field of formal analysis of internationalbehavior, and the technical quality of the work is cutting edge. This book would be asplendid overview for anyone wishing to get a thorough introduction to the majorissues involved in assessing the liberal peace hypothesis. About half of the articleshave appeared previously in journals; the other half are new to print.

An edited book that emerges from a project involving this level of interactionruns clear risks of being anachronistic by the time it appears or being accessible onlyto those who were involved in the research. Globalization and Armed Conflict suc-cessfully avoids these potential pitfalls, and in several respects it makes excellent use

r 2004 International Studies Review.PublishedbyBlackwellPublishing,350MainStreet,Malden,MA02148,USA,and9600GarsingtonRoad,OxfordOX42DQ,UK.

International Studies Review (2004) 6, 292–294

of the prior communication. For example, the level of agreement on the terms ofdebate and common use of data sources characteristic of the volume make it rel-atively easy to compare the results of alternative approaches. Moreover, readers willsee two instances of active debates: John Oneal and Bruce Russett contending withNathaniel Beck about how to estimate effects in dyad-year data, and KatherineBarbieri and Jack Levy contending with Charles Anderton and John Carter aboutthe degree to which war disrupts trade. It should be further noted that the editorsthemselves disagree on the validity of the liberal peace hypothesis, with Schneiderand Gleditsch being somewhat more supportive than Barbieri.

Nonetheless, some redundancy does exist in the volume, and, given the extent towhich the chapters are focused on a single issue, this duplication is perhaps higherthan that found in most edited volumes. For example, even though the editorssummarize much of the prevailing theory in their introductory chapter, some ofthe subsequent chapters either repeat or add to this overview. A single more com-prehensive theory chapter would have been useful. Similarly, a single description ofthe data sets on both trade and conflict would have been useful.

Chapters developing theoretical explanations use technical approaches fromconventional neoclassical economics and game theory. Unfortunately, little effort ismade to directly link the theoretical expositions with the empirical tests. The the-oretical models are parameter rich, but no attempt is made to constrain the valuesof those parameters through statistical estimation. The statistical analyses, mean-while, generally employ standard linear or log-linear formulations (albeit with fre-quently elaborate error structures and estimation methods) without any referenceto how these formulations are suggested by the theories. Thus, even though thestories being told by the theory and the data analysis are similar, the mathematics isin fact quite divergent. In fairness to the book, this problem is widespread incontemporary technical social science research.

A major conceptual criticism that can be raised concerns the narrowness withwhich the editors and contributors have interpreted the terms ‘‘globalization’’ and‘‘armed conflict.’’ In fact, virtually all the work in this volume and in the literaturegenerally focuses on international trade, and to a more limited extent, economicdevelopment. Moreover, with the exception of one chapter on internal conflict byHvard Hegre, Ranveig Gissinger, and Gleditsch, the focus of the volume is oninterstate conflict (including wars and militarized disputes). Nor is the equation of‘‘trade’’ and ‘‘globalization’’ merely a marketing decision with respect to the title.(The marketing value of the term is, however, suggested by the fact that, in lateNovember 2003, a search for books on Amazon.com returned 1,447 entries with‘‘globalization’’ in the title.) The tendency to equate globalization with trade actuallypervades the entire book.

This narrow definition excludes many other positive and negative processes thatare frequently considered part of globalization, such as the coordination of nationalpolicies on banking, labor, and environmental regulation, the global HIV/AIDSepidemic, and the global scientific response to HIV/AIDS. Given a broader def-inition, an argument could be made that over the past fifteen years the most im-portant effect of globalization on conflict has been the lethal combination of anincrease in the availability of small armsFfollowing the collapse of the Soviet Un-ionFand the increased ability of groups to buy those weaponsFusing funds fromthe global markets in oil, diamonds, timber, and narcotics (see, for example, Car-negie Commission on Preventing Deadly Conflict 1997; Kaldor 1998; Berdal andMalone 2000). None of the articles in Globalization and Armed Conflict begins toapproach issues such as this, which require a broader view of either the independ-ent or dependent variable.

What is the relationship between trade and interstate war? A table in the intro-ductory chapter by Schneider, Barbieri, and Gleditsch (pp. 17–18) summarizesforty published statistical studies that have attempted to test a linkage between

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various measures of trade and various measures of conflict, using a variety ofcontrol variables and statistical methods. Nineteen of these studies confirm thenegative relationship between trade and war that is posited by the liberal peacehypothesis. However, fourteen of the studies find a positive relationship, and sevenmore are indeterminate. The chapters in this volume generally reflect this division.Clearly, some empirical evidence and supporting theory exist to support the prop-osition that trade helps reduce interstate conflict, but this result is fragile and in alllikelihood requires substantially more caveats than does the democratic peace the-orem (which, of course, is also still somewhat contested).

Globalization and Armed Conflict is not the final word on the relationship betweentrade and warFlet alone the relationship between globalization and armed conflict.But the book does provide an excellent snapshot of the state of current researchconcerning the liberal peace hypothesis. The book would probably not be appro-priate in an undergraduate setting, but the level of technical difficulty is comparableto that found in the American Political Science Review and the American Journal ofPolitical Science, and therefore the work should be accessible to most researchers anddoctoral-level graduate students.

References

BERDAL, MATS, AND DAVID M. MALONE, EDS. (2000) Greed and Grievance: Economic Agendas in Civil Wars.Boulder: Lynne Rienner Publishers.

CARNEGIE COMMISSION ON PREVENTING DEADLY CONFLICT. (1997) Preventing Deadly Conflict. Washing-ton, DC: Carnegie Commission on Preventing Deadly Conflict.

CHAN, STEVE. (1997) In Search of Democratic Peace. Mershon International Studies Review 41:59–91.KALDOR, MARY. (1998) New and Old Wars: Organized Violence in a Global Era. Palo Alto: Stanford

University Press.KEOHANE, ROBERT O., AND JOSEPH S. NYE. (1977) Power and Interdependence: World Politics in Transition.

Boston: Little, Brown.RAY, JAMES LEE. (1995) Democracy and International Politics: An Evaluation of the Democratic Peace Prop-

osition. Columbia: University of South Carolina Press.RUSSETT, BRUCE, AND JOHN ONEAL. (2001) Triangulating Peace: Democracy, Interdependence and Inter-

national Organizations. New York: W.W. Norton.

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