Complementary mediation: Exploring mediator composition in civil wars

Mediators improve the chances disputants in civil wars sign a peace agreement by exerting pressure or influence, referred to as leverage. This paper explores how sources of mediator leverage complement one another and draws attention to an under-explored form of influence: credible staying power. I argue that softer forms of leverage (i.e. relationships with the disputants and credible staying power) complement material strength, providing the highest chance of reaching a peace agreement when used together. As multiple sources of leverage mean multiple mediators, this paper also explores the number of and coordination among mediators, acknowledging the tension between multiple mediators increasing available leverage while complicating negotiations by adding more voices to the negotiating table. I argue that more mediators, all else equal, will decrease the probability of success; this effect can be offset, however, by coordination among the mediators. Empirical analysis of 312 mediation efforts in civil wars from 1989 to 2006 find that softer forms of leverage do reinforce material power, producing the greatest probability of reaching a signed agreement when used together. Moreover, coordination substantially mitigates the negative effect of additional mediators.