Speaking with one voice: Coalitions and wartime diplomacy

ABSTRACT When and why do countries in a wartime coalition engage in diplomacy during hostilities? This paper establishes a theoretical framework of coalitional diplomacy that highlights each member’s private costs and benefits to fighting or seeking a negotiated exit. I argue that the propensity for coalition members to engage in negotiations is a function of the coalition’s balance of military contributions, as well as the coalition’s battlefield successes and failures. Evidence supporting these claims stem from a large-scale quantitative analysis of two centuries of interstate wars, as well as a close study of the Allies in the Crimean War.