Basic logic
Fearon (1995) argued that because war costs lives and resources, two rational states would both be better off anticipating the outcome of a war and agreeing to a settlement reflecting it. If both knew that one side would win with 70 percent probability, dividing the issue in proportion to that expected outcome would spare them the costs of fighting. Hence a bargaining range exists that both prefer to war. The question of the bargaining model thus shifts from why war happens to why bargaining fails even though such agreements are available.
Why bargaining fails
Fearon offered three rationalist explanations. First, states hold private information about their capabilities or resolve and have incentives to bluff to obtain better terms, so their opponents cannot trust what they say. Second, when the distribution of power shifts, a commitment problem arises because the rising side cannot credibly promise to honor a deal in the future; this links to the logic of preventive war. Third, if the issue at stake is indivisible, compromise is difficult. Powell (2006) brought several causes of war together as commitment problems. Audience cost theory connects to the model as a signaling device that reduces information problems.
Wartime bargaining and assessment
Wagner (2000) argued that war should be seen not as the end of bargaining but as part of the bargaining process. Filson and Werner (2002) modeled how battlefield outcomes reveal information about relative power, leading sides to adjust their demands until war ends. Slantchev (2003) analyzed a principle of convergence under which settlement occurs as the two sides' expectations converge during war. Reiter (2003) reviewed this research program, and Lake (2010), analyzing the Iraq War, concluded that bargaining theory is useful but must be complemented by factors such as leaders' misperceptions and domestic politics. The bargaining model is a prominent application of game theory to international conflict.
FAQ
- What is the bargaining model of war in simple terms?
- Because war is costly, both countries would gain from agreeing without fighting. The theory explains that bargaining breaks down and war occurs when sides cannot accurately know each other's strength or cannot trust each other's promises.
- What is the commitment problem in the bargaining model?
- It is the problem that even if a deal is reached now, a side that grows stronger later may break it, so the other side cannot trust the promise. As a result, a declining state may choose to fight while it still has an advantage.
Sources reviewed: 2026-10-26
References
- Fearon, J. D. (1995). Rationalist explanations for war. International Organization, 49(3), 379–414. The founding paper — start here for why private information and commitment problems cause war.
- Wagner, R. H. (2000). Bargaining and war. American Journal of Political Science, 44(3), 469–484. Treats war itself as part of the bargaining process — key for seeing fighting and negotiating as one.
- Filson, D., & Werner, S. (2002). A bargaining model of war and peace: Anticipating the onset, duration, and outcome of war. American Journal of Political Science, 46(4), 819–837. One model for onset, duration and outcome — shows fighting as a way of revealing information.
- Reiter, D. (2003). Exploring the bargaining model of war. Perspectives on Politics, 1(1), 27–43. An accessible review of the whole research program — ideal for getting the big picture.
- Slantchev, B. L. (2003). The principle of convergence in wartime negotiations. American Political Science Review, 97(4), 621–632. Expectations converge during war until settlement — how wars end.
- Powell, R. (2006). War as a commitment problem. International Organization, 60(1), 169–203. Unifies several causes of war as commitment problems — for the information vs. commitment distinction.
- Lake, D. A. (2010). Two cheers for bargaining theory: Assessing rationalist explanations of the Iraq War. International Security, 35(3), 7–52. Tests bargaining theory on the Iraq War — strengths and limits in a real case.