James Fearon, “Rationalist Explanations for War”

Causes of War

What is the main argument?

The main argument centers on the puzzle of war: since fighting is costly and risky, truly rational states should always be able to locate a negotiated settlement they prefer to war. Therefore, the author argues that most standard rationalist explanations for war fail because they do not address why states are unable to reach these mutually preferable ex ante (pre-war) bargains.

What is the argument against standard views?

1. Anarchy: while the anarchical nature of the international system is often cited as a cause of war, merely noting that nothing prevents states from using forces does not explain why force (a costly option) is ever employed, or how the lack of a central authority prevents states from negotiating mutually preferable agreements. 

2. Positive expected utility: This argument fails because the ex post inefficiency of war opens up an ex ante bargaining range provided that the issues are divisible or side-payments are possible, a set of negotiated agreements should exist that both sides prefer to the gamble of war.

3. Rational preventive war: Fails because they do not consider why a rising and declining power could not construct a bargain that would leave both sides better off than a costly war.

What is the first of two general mechanisms that provide the foundations for a coherent rationalist theory of war by explaining why rational states might fail to locate or agree on a peaceful bargain?

Mechanism 1: Private information and Incentives to Misrepresent

1. States have private information about militarily relevant factors. If both sides are overly optimistic about their chances of victory, they believe no mutually preferred settlement exists.

2. Even if rational leaders know that sharing information would reveal a peaceful settlement, they also have strategic incentives to misrepresent or exaggerate their true willingness or capability to fight in order to gain a more favorable deal in bargaining. 

3. Due to these 2 reasons, the quiet diplomatic conversations may fails to credibly transmit information. An example of this is WWI when the German leaders dismissed Russian warnings as “bluffing,” or in the Russo-Japanese war where Russian overconfidence stemmed from Japanese private information about their superior capabilities.

What is the second of the two mechanisms?

Mechanism 2: Commitment problems

1. Mutually preferable bargains may be unattainable when, for structural reasons related to anarchy, states cannot trust each other to uphold the deal due to no enforcer.

Specific contexts this applies to:

1. Preventive war (power shifts): When military power is expected to shift overtime, a declining state (or the state that faces a rising state) attacks because it fears the unfavorable peace (the disadvantageous negotiated settlement) it will be forced to accept when the rival grows stronger.

2. Preemptive War (offensive strategies): If military technology or geography creates a large first-strike advantage or offensive advantages for both states, these incentives narrow the bargaining range. Large first-strike incentives can make all mutually preferable agreements unenforceable and incredible because both sides are highly tempted to attack unilaterally.

3. Bargaining over strategic territory: when the issue being bargained over (like strategically vital territory) is itself a source of future military power, ceding territory may radically increase the recipient state’s future bargaining leverage. The granting state may prefer war because it cannot trust the recipient not to exploit the resulting future leverage.