This article examines the relationship between the structure of politico-military movements and effective insurgent engagement in peace processes. Drawing on the experiences of Irish republicans and Basque separatists, I argue that centralized movement structures in which politicos wield influence over armed groups allow for effective coordination between movement wings in peace efforts while providing political leaders with credibility as interlocutors. In the Irish case, centralization enabled Sinn Fein leaders to ensure Provisional ira commitment to peace and to contain schism within the republican movement throughout the peace process. In the Basque case, movement decentralization created persistent coordination problems between wings during peace efforts, while eta’s unilateral reneging prevented political allies from establishing credibility as peacemakers. These cases show that while movement leaders untainted by direct association with armed groups may be more politically palatable than those with ties to “terrorists”, tainted leaders may make more credible partners for peace.
