Rationalist explanations for war

TitleRationalist explanations for war
Publication TypeJournal Article
AuthorsFearon, JD

The central puzzle about war is that wars are costly but nonetheless still occur. This article focuses on rationalist explanations, which can also be called "neorealist explanations".

This article attempts to provide a clear statement of what a rationalist explanation for war is and to characterize the full set of rationalist explanations that are both theoretically coherent and empirically plausible. Despite its prominence, neorealist theory lacks a clearly stated and fully conceived explanation for war. It is not enough to say that under anarchy nothing stops states from using force, or that anarchy forces states to rely on self-help, which engenders mutual suspicion and (through spirals or the security dilemma) armed conflict. Neither do diverse references to miscalculation, deterrence failure because of inadequate forces or incredible threats, preventive and preemptive considerations, or free-riding in alliances amount to theoretically coherent rationalist explanations for war.

My main argument is that upon close inspection none of the principal rationalist arguments advanced in the literature holds up as an explanation because none address or adequately resolves the central puzzle, namely, that war is costly and risky, so rational states should have incentives to locate negotiated settlements that all would prefer to the gamble of war. The common flaw of standard rationalist explanations is that they fail either to address or to adequately explain what prevents leaders from reaching ex ante (prewar) bargains that would avoid the costs and risks of fighting. A coherent rationalist explanation for war must do more than give reasons why armed conflict might appear an attractive option to a rational leader under some circumstances--it must show why states are unable to locate an alternative outcome that both would prefer to a fight.

This article will consider 5 rationalist arguments accepted as tenable in the literature on the causes of war:
1. Anarchy
2. expected benefits greater than expected costs
3. rational preventative war
4. rational miscalculation due to lack of information
5. rational miscalculation or disagreement about relative power.

I argue that the first three arguments simply do not address the question of what prevents state leaders from bargaining to a settlement that would avoid the costs of fighting. The 4th and 5th arguments do address the question, holding that rational leaders may miss a superior negotiated settlement when lack of information leads to miscalculate relative power or resolve. However, as typically stated, neither argument explains what prevents rational leaders from using diplomacy or other forms of communication to avoid such costly miscalculations.

If these standard arguments do not resolve the puzzle on rationalist terms, what does? I propose that there are three defensible answers, which operate in the form of general mechanisms, or causal logics.

1. Private information about relative capabilities or resolve and incentives to misrepresent information.
2. Commitment problems create situations in which mutually preferable bargains are unattainable because one or more states would have an incentive to renege on the terms. In particular, preventive war between rational states stems from a commitment problem rather than from differential power growth per se.
3. Issue indivisibilites prevent a resolution that falls within the range that both prefer to fighting. However, the issues over which states bargain typically are complex and multidimensional; side-payments or linkages with other issues typically are possible. War prone international issues may often be effectively indivisible, but the cause of this indivisibility lies in domestic political and other mechanisms rather than in the nature of the issues themselves.

The first two mechanisms provide the foundations for a rationalist or neorealist theory of war.