Regime Type, War Aims, and Coalition Member Effort in Combat

States often form battlefield coalitions to combat a shared foe, but are frequently frustrated by their partners’ underwhelming efforts while fighting. Why? Using selectorate theory, this chapter contends regime type conditions belligerents’ composition of forces and war aims, which then shape provision of effort in combat. Democratic states, with capital-heavy forces and war aims emphasising international collective goods, tend to shirk and free-ride on their partners’ efforts during the fighting. Non-democratic states, relying on labour-heavy forces and emphasising private goods war aims, are reluctant to form coalitions and push for operations that benefit them more than the collective. In mixed-regime battlefield coalitions, belligerents’ divergent types of forces and war aims create conflicting pressures that undermine cohesion and coordination. The argument is assessed through case studies of three coalition combat efforts during the World Wars. The results strongly support the claim laid out in this chapter and have implications for scholarship on coalition duration and termination, burden-sharing, and democratic warfighting.