Scott Wolford‘s article, “Showing Restraint, Signaling Resolve: Coalitions, Cooperation, and Crisis Bargaining,” appears in the January 2014 issue of the AJPS. Here, he provides a summary of its content and major conclusions:

Powerful countries like the United States often find themselves building military coalitions, yet fighting with “friends and allies” isn’t always viewed in a positive light. In fact, it’s generally accepted that coalition partners water down threats and generally make matters more complicated when it comes to powerful countries getting what they want from their enemies. I present a theory that shows this conventional wisdom is often wrong. Even when coalition partners water down threats, demanding limits on the scale of military operations in return for their cooperation, their presence can either raise or lower the chances of war.

Here’s the story: Suppose that a state (let’s call it the leader) would like to convince its opponent that it’s truly willing to fight over an issue, but its opponent has reason to doubt it. Typically, getting the opponent to believe such a threat requires doing something costly, like mobilizing the military. However, sending this kind of signal gets complicated when the leader would also like to ensure the support of a coalition partner, whose military contribution can help it win the war but who will also only stay in the coalition if the war won’t be too costly. In this case, since the costs of war fall differently across members of coalitions, keeping the coalition together entails the leader watering down its own threats.

The result of this desire to secure a partner’s cooperation is that sometimes coalition leaders knowingly send “weak” signals—for example, they will prep a bombing campaign rather than an invasion—that their opponents don’t find credible, which leads to war (typically against weaker opponents). It’s tragic, and if the leader didn’t have the option to build a coalition, war wouldn’t break out. In other words, working with partners can actually make war more likely than it otherwise would be. On the other hand, against stronger opponents, partners can discourage leaders from bluffing about their resolve, which would increase the chances of war; this is surely a good thing when facing strong opponents that would be difficult to defeat in war. Ultimately, my research shows that coalition partners are neither always bad news nor always conducive to peace. Whether coalition-building leads to peace or war depends, in the final accounting, on precisely why coalition leaders make weak or watered down threats.