¹ See, for example, Russett, Bruce, Oneal, John R., and Davis, David, “The Third Leg of the Kant-ian Tripod for Peace: International Organizations and Militarized Disputes, 1950–1985,” International Organization 52, no. 3 (1998)Google Scholar; Russett, Bruce and Oneal, John R., Triangulating Peace: Democracy, Interdependence, andInternational Organizations (New York: W. W. Norton, 2001)Google Scholar.

² See Oneal, John R. and Russett, Bruce, “The Kantian Peace: The Pacific Benefits of Democracy, Interdependence, and International Organizations, 1885–1992,” World Politics 52 (October 1999)CrossRefGoogle Scholar; Gartzke, Erik, Li, Quan, and Boehmer, Charles, “Investing in the Peace: Economic Interdependence and International Conflict,” International Organization 55, no. 2 (2001)CrossRefGoogle Scholar.

³ Mearsheimer, John, “The False Promise of International Institutions,” International Security 19, no. 3 (1995)Google Scholar; Schweller, Randall L. and Preiss, David, “A Tale of Two Realisms: Expanding the Institutions Debate,” Mershon International Studies Review 41, no. 1 (1997)CrossRefGoogle Scholar. And for reviews of and perspectives on the literature, see Martin, Lisa L. and Simmons, Beth A., “Theories and Empirical Studies of International Organizations,” International Organization 52, no. 4 (1998)CrossRefGoogle Scholar.

⁴ See, for example, Haas, Ernst B., Beyond the Nation-State: Functionalism andInternational Organization (Palo Alto, Calif.: Stanford University Press, 1964)Google Scholar; Keohane, Robert O. and Nye, Joseph S., Power and Interdependence (New York: Harper Collins, 1989)Google Scholar; Young, Oran R., “International Regimes: Toward a New Theory of Institutions,” WorldPolitics 39 (October 1986)Google Scholar; idem, “The Effectiveness of International Institutions: Hard Cases and Critical Variables,” in Rosenau, James M. and Czempiel, Ernst-Otto, eds., Governance without Government (Cambridge: Cambridge University Press, 1992)CrossRefGoogle Scholar; Ruggie, John Gerard, “Continuity and Transformation in the World Polity: Toward a Neorealist Synthesis,” World Politics 35 (January 1983)CrossRefGoogle Scholar; idem, “The False Promise of Realism,” International Security 20, no. 1 (1995)Google Scholar; James M. Rosenau, “Citizenship in a Changing Global Order,” in Rosenau and Czempiel, Governance without Government, and Wendt, Alexander, “Constructing International Politics,” International Security 20, no. 1 (1995)CrossRefGoogle Scholar.

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⁶ Snidal (fn. 5) points out that contrasting predictions of absolute and relative gains depend on the number of actors involved. For an informative debate, see comments by Grieco, Joseph M., Powell, Robert, and Snidal, Duncan, “The Relative-Gains Problem for International Cooperation,” American Political Science Review 87, no. 3 (1993)CrossRefGoogle Scholar. See also Mosher, James S., “Relative Gains Concerns When the Number of States in the International System Increases,” Journal of Conflict Resolution 47, no. 5 (2003)CrossRefGoogle Scholar; and Rousseau, David L., “Motivations for Choice: The Salience of Relative Gains in International Relations,” Journal of Conflict Resolution 46, no. 3 (2002)CrossRefGoogle Scholar.

⁷ Subsequent research suggests that the shadow of the future can actually inhibit cooperation. See Signorino, Curtis S., “Simulating International Cooperation under Anarchy: The Effects of Symmetric and Asymmetric Noise,” Journal of Conflict Resolution 40, no. 1 (1996)CrossRefGoogle Scholar; Fearon, James D., “Bargaining, Enforcement, and International Cooperation,” International Organization 52, no. 2 (1998)CrossRefGoogle Scholar; Barkin, J. Samuel, “Time Horizons and Multilateral Enforcement in International Cooperation,” International Studies Quarterly 48, no. 2 (2004)CrossRefGoogle Scholar.

⁸ Singer, J. David and Wallace, Michael, “Intergovernmental Organization and the Preservation of Peace, 1816—1964: Some Bivariate Relationships,” International Organization 24, no. 3 (1970)CrossRefGoogle Scholar; Wallace, Michael and Singer, J. David, “Intergovernmental Organization in the Global System, 1815–1964: A Quantitative Description,” International Organization 24, no. 2 (1970)CrossRefGoogle Scholar; Domke, William, War and the Changing Global System (New Haven: Yale University Press, 1988)Google Scholar; Young (fn. 4, 1992); Martin and Simmons (fn. 3).

⁹ Martin and Simmons (fn. 3) provide a review of the extensive case study literature.

¹⁰ Oneal, John R., Russett, Bruce, and Berbaum, Michael L., “Causes of Peace: Democracy, Interdependence, and International Organizations,” International Studies Quarterly 47, no. 3 (2003)Google Scholar; Oneal and Russett (fn. 2); Russett, Oneal, and Davis (fn. 1).

¹¹ Harold Jacobson and Domke (fn. 8) provide typologies of IGOs; Jacobson, , Networks ofInterde-pendence: International Organizations and the Global Political System (New York: Knopf, 1984)Google Scholar. However, Harold Jacobson, William M. Reisinger, and Todd Mathers use an inappropriate dependent variable, whereas Domke relies on disaggregated probit estimates for each year; see Jacobson, Reisinger, and Mathers, “National Entanglements in Governmental Organizations,” American Political Science Review 80, no. 1 (1986).

¹² Oneal and Russett (fn. 2); and Gartzke, Li, and Boehmer (fn. 2).

¹³ Singer and Wallace (fn. 8).

¹⁴ Mearsheimer (fn. 3).

¹⁵ Ibid., 13.

¹⁶ Schweller and Preiss (fn. 3).

¹⁷ Fearon, James D., “Rationalist Explanations for War,” International Organization 49, no. 3 (1995)CrossRefGoogle Scholar. See also Morrow, James D., “Capabilities, Uncertainty, and Resolve: A Limited Information Model of Crisis Bargaining,” American Journal of Political Science 33, no. 2 (1989)CrossRefGoogle Scholar.

¹⁸ For reviews of the rationalist literature on bargaining and war, see Reiter, Dan, “Exploring the Bargaining Model of War,” Perspectives on Politics 1, no. 1 (2003)CrossRefGoogle Scholar; and Powell, Robert, “Bargaining Theory and International Conflict,” Annual Review of Political Science 5 (2002)CrossRefGoogle Scholar. For a critique, see Kirshner, Jonathan, “Rationalist Explanations for War?” Security Studies 10, no. 1 (2000)CrossRefGoogle Scholar.

¹⁹ The notion that IGOs are selective in their mediation efforts is contrasted by normative and institutional incentives to intervene. Unlike peacekeeping, say, where the investment is high, organizing talks, pressuring delegates, brokering deals, informing parties, and promoting sanctions are all relatively low-cost actions. These activities are often explicitly encouraged by IGO charters, members, and interested publics. Indeed, the proliferation of security IGOs, the bulk of which are unequipped to impose peace, would appear peculiar if they were not meant to conduct such activities.

²⁰ Formal models serve, among other things, to tie tests of implications of an argument to untested elements of a theory. See Morton, Rebecca B., Methods andModels:A Guide to the EmpiricalAnalysis of FormalModels in Political Science (Cambridge: Cambridge University Press, 1999)CrossRefGoogle Scholar.

²¹ States can have no incentive to dispute benefits that cannot be denied to the loser or third parties. If players value relative gains, however, war can result from nonrivalrous goods.

²² Fearon's list is not exhaustive. Risk acceptance can motivate contests, as can a consumption value for war. There is also a broader set of commitment problems that is assumed away by Fearon's modeling framework. See, for example, Garfinkel, Michelle R. and Skaperdas, Stergios, “Conflict without Misperception or Incomplete Information: How the Future Matters,” Journal of Conflict Resolution 44, no. 6 (2000)CrossRefGoogle Scholar; Slantchev, Branislav, “The Power to Hurt: Costly Conflict with Completely Informed States,” American Political Science Review 97, no. 1 (2003)CrossRefGoogle Scholar. Still, Fearon's characterization of war is coherent, widely addressed in the literature, and tractable.

²³ Trask, David F., The War with Spain in 1898 (New York: Macmillan, 1981), 445–66Google Scholar. “The likelihood of an agreement was greatly assisted by a proposal emanating from Senator Frye that the United States should offerfinancialcompensation in exchange for the Philippines”; Smith, Joseph, The Spanish-American War: Conflict in the Caribbean (London: Longman, 1994), 199–200Google Scholar.

²⁴ States often have incentives to seek to generate indivisibilities. Commitment increases bargaining power by making it harder to compromise. Third parties could allow states to extract themselves from commitments. Blaming an IGO for having to renege on a promise may free a leader from domestic audience costs, for example. It is also possible, however, that IGOs increase opportunities for generating indivisibilities. IGOs allow leaders to formalize agreements that are later binding (or at least impinging) on domestic politics. We do not explore these issues here.

²⁵ Commitment problems and indivisibilities may be more prevalent in intrastate conflict, where settlements often include a loss of autonomy for one of the competing parties or where any settlement implies recognition, which is part of the stakes in the contest. See Walter, Barbara F., “Explaining the Intractability of Territorial Conflict,” International Studies Review 5, no. 4 (2003)CrossRefGoogle Scholar; Toft, Monica Duffy, The Geography of Ethnic Violence: Identity, Interests, and the Indivisibility of Territory (Princeton: Princeton University Press, 2003)Google Scholar; Fearon, James D. and Laitin, David, “Explaining Interethnic Cooperation,” American Political Science Review 90, no. 4 (1996)CrossRefGoogle Scholar; idem, “Ethnicity, Insurgency, and Civil Wat,” American Political Science Review 97, no. 1 (2003)Google Scholar.

²⁶ For a succinct and highly intuitive account of the bargaining argument, see also Morrow, James D., “How Could Trade Affect Conflict?” Journal of Peace Research 36, no. 4 (1999)CrossRefGoogle Scholar.

²⁷ Gartzke, Erik, “War Is in the Error Term,” International Organization 53, no. 3 (1999)CrossRefGoogle Scholar. The asymmetric information argument is not theoretically sufficient to explain war. A sufficient account of the causes of war requires that researchers access the private information of competing states.

²⁸ Fearon (fn. 17) provides a formal proof. We use Fearon as the basis for our theory. Powell, Robert, In the Shadow of Power: States and Strategies in International Politics (Princeton: Princeton University Press, 1999)Google Scholar; idem, “The Inefficient Use of Power: Costly Conflict with Complete Information” American Political Science Review 98, no. 2 (2004)Google Scholar. Garfinkel and Skaperdas (fn. 22); and Slantchev (fn. 22) offer alternative bargaining frameworks in which commitment problems are a more important cause of war and contests can occur under full information. Which characterization of bargaining is most general empirically remains a subject of debate. Note, however, that alternative conceptions hinge on assumptions about the sequence of offers in bargaining. Since states often negotiate about how they will negotiate (structure is endogenous), and since a satisfactory theory of this aspect of bargaining has yet to be introduced to international relations, we adopt the simplest model of bargaining as a place of departure. The theory we supply is shown here to better explain observed behavior than conventional liberal or realist alternatives.

²⁹ The security dilemma makes clear the zero-sum nature of dynamics in the balance of power. However, realists have failed to extend the insight to diplomatic bargaining. Factors that alter the likely outcomes of contests should alter the demands of diplomats in roughly the same fashion.

³⁰ Changing the payoffs in the chicken game alters play only if changes are ordinal. The effect is stronger in a bargaining game, where competitors set payoffs endogenously through their offers.

³¹ A review of the traditional literature on the effects of third-party mediation can be found in Gilady, Lilach and Russett, Bruce, “Peace-Making and Conflict Resolution,” in Carlesnaes, Walter, Risse, Thomas, and Simmons, Beth, eds., Handbook ofInternational Relations (London: Sage, 2002)Google Scholar.

³² For a discussion of credible diplomacy, see Sartori, Anne, “The Might of the Pen: A Reputational Theory of Communication in International Disputes,” International Organization 55, no. 3 (2002)Google Scholar.

³³ IGOs must also convince states of the veracity of information. Paradoxically, a third-party intent only on averting a contest may be less effective than a biased actor with preferences over the outcome of bargaining. Randall Calvert demonstrates that information from biased political sources can be informative; Calvert, , “The Value of Biased Information: A Rational Choice Model of Political Advice,” Journal of Politics 47, no. 2 (1985)CrossRefGoogle Scholar. Andrew Kydd extends this logic to the context of third-party mediation of interstate conflicts; Kydd, , “Which Side Are You On? Bias, Credibility, and Mediation,” American Journal of Political Science 47, no. 4 (2003)CrossRefGoogle Scholar. In a subsequent paper, Kydd points out that reputation can be used to make unbiased mediators more credible, though the balance between costs and credibility is critical. See Andrew Kydd, “The Honest Broker: Mediation and Mistrust” (Manuscript, Harvard University, Cambridge, July 2004). Similarly, Robert W. Rauchhaus relaxes the assumption that mediators prefer peace; Rauchhaus, “Asymmetric Information, Mediation and Conflict Management” (Manuscript, University of California, Santa Barbara, 2003).

³⁴ Secret threats lack the consequences often viewed as critical to successful deterrence. See Powell, Robert, Nuclear Deterrence Theory: The Searchfor Credibility (Cambridge: Cambridge University Press, 1990)CrossRefGoogle Scholar. Uncertainty about third-party actions could increase the onset of disputes.

³⁵ Neutral third parties, while arguably less effective at information arbitrage, are likely to be more effective at intervention and constraint. Biased IGOs may fail to constrain their favored faction, leading to more extractive demands and a higher risk of war.

³⁶ Actors can autonomously reveal resolve through costly actions, but “burning money” also weakens bargaining power. We should see such actions only when the reduction in uncertainty leads to payoffs exceeding the cost in resources and the loss of leverage. See David Austen-Smith and Jeffrey S. Banks, “Cheap Talk and Burning Money” (Manuscript, Northwestern University, Evanston, Ill., and the California Institute of Technology, Pasadena, Calif, 1998).

³⁷ Gartzke, Li, and Boehmer (fn. 2).

³⁸ All results mentioned but not published in the study are available from the authors.

³⁹ Oneal and Russett (fn. 2). We collected data on institutionalization for 297 IGOs, coding 198 as “minimal,” 52 as “structured,” and 47 as “interventionist.” Details for defunct IGOs are often unavailable.

⁴⁰ Beck, Nathaniel, Katz, Jonathan N., and Tucker, Richard, “Taking Time Seriously: Time-Series-Cross-Section Analysis with a Binary Dependent Variable,” American Journal of Political Science 42, no. 4 (1998)CrossRefGoogle Scholar.

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⁴² Zeev Maoz, “Dyadic Militarized Interstate Disputes (DYMID 1.1) Dataset, Version 1.1” (Code-book, Department of Political Science, Tel Aviv University, 1999).

⁴³ For a useful discussion of the debate over onset and ongoing MIDs, see Bennett, D. Scott and Stam, Allan, “Research Design and Estimator Choices in the Analysis of Interstate Dyads: When Decisions Matter,” Journal of Conflict Resolution 44, no. 5 (2000)CrossRefGoogle Scholar.

⁴⁴ Oneal and Russett (fn. 2). Replication is approximate given idiosyncrasies in data and coding.

⁴⁵ Wallace and Singer (fn. 8). COW data are reported in five-year intervals. We interpolate missing values, as do Oneal and Russett (fn. 2).

⁴⁶ Union of International Associations, Yearbook ofInternational Organizations (Munich: K.G. Saur, various years).

⁴⁷ Arthur Banks and Thomas C. Muller, Political Handbook of the World (Binghamton, N.Y.: CSA Publications, various years).

⁴⁸ Affinity provides annual measures of the similarity of dyadic voting positions in the General Assembly (1946–96). Data construction is discussed elsewhere. See Gartzke, Erik, “Kant We AH Just Get Along? Motive, Opportunity, and the Origins of the Democratic Peace,” American Journal of Political Science 42, no. 1 (1998)CrossRefGoogle Scholar; idem, “Preferences and the Democratic Peace,” International Studies Quarterly 44, no. 2 (2000)Google Scholar. We use the United States as the reference country to convert dyadic values to monadic values. We also examined a variable based on nominate coding of state ideal points used in Voeten, Erik, “Clashes in the Assembly,” International Organization 54, no. 2 (2000)CrossRefGoogle Scholar. Designation of ideal points involves additional assumptions about state utilities that are not immune to controversy and that yield nonintuitive results in our analysis.

⁴⁹ We also created an alternative measure of IGO member contentiousness by inverting and summing quartiles. The resulting variables correlate highly with the IGO institutionalization variables.

⁵⁰ In future research we plan to explore selection effects in IGOs using a different unit of analysis.

⁵¹ Oneal and Russett (fn. 2).

⁵² Jaggers, Keith and Gurr, Ted R., “Transitions to Democracy: Tracking Democracy's ‘Third Wave’ with the Polity III Data” Journal of Peace Research 32, no. 4 (1995)CrossRefGoogle Scholar.

⁵³ Russett, Oneal, and Davis (fn. 1).

⁵⁴ Ibid; Gartzke, Li, and Boehmer (fn. 2).

⁵⁵ Oneal and Russett (fn. 2). We use Oneal and Russett s data and statistical model to establish a baseline for comparison. The changes in data and variable construction mentioned previously are reported in subsequent tables. We also replicated all regressions using the ReLogit procedure, but found no substantive differences in results. See King, Gary and Zeng, Langche, “Explaining Rare Events in International Relations,” International Organization 55, no. 3 (2001)CrossRefGoogle Scholar; idem, “Logistic Regression in Rare Events Data,” Political Analysis 98 (2001)Google Scholar.

⁵⁶ Beck, Katz, and Tucker (fn. 40).

⁵⁷ Oneal and Russett (fn. 2); Gartzke, Li, and Boehmer (fn. 2).

⁵⁸ Aggregating memberships at the level of the dyad is far from ideal. We use the dyad as the unit of analysis to facilitate comparison of our results with other quantitative studies ofIGOs.

⁵⁹ Powell (fn. 28, 2004); idem, “Bargaining and Learning while Fighting,” American Journal of Political Science 48, no. 2 (2004)Google Scholar; Slantchev (fn. 22).

⁶⁰ Wagner, R. Harrison, “Bargaining and War,” American Journal of Political Science 44, no. 3 (2000)CrossRefGoogle Scholar.

⁶¹ Holbrooke, Richard, To End a War (New York: Random House, 1998)Google Scholar.

⁶² Game-theoretic models often include the status quo as an outcome. We treat the status quo as a special case of the equilibrium in which the bargain in the game equals the bargain ex ante.

⁶³ Having A sweeten its offer by making an arbitrarily small concession ε leads B to strictly prefer d to fighting. However, this clutters the model while yielding no new substantive conclusions.

⁶⁴ Actors may be limited in their ability to optimize by the bounded nature of parameter values or by constraints imposed by third parties (assuming opponents are restrained from altering demands).

⁶⁵ This result depends on the inability of B to make a counteroffer. In an iterated game, B could use the vulnerability of A to extract additional concessions, much as A does to B in proposition 1.

⁶⁶ Using 1 as the upper bound would both allow that the third party is more eager for a contest than A (not likely) and eliminate the possibility that I values the stakes more than A.