For collective action to occur and be sustainable, social movements must construct collective identities and develop a sense of themselves as collective actors. This is especially difficult for movements that work across deep political and cultural chasms, and in situations of protracted conflict. Yet, there has been almost no research on how movement organizations, which work across conflict lines in situations of protracted conflict, are able to establish this sense of cohesion. This project investigates how two joint Israeli-Palestinian peace movement organizations are able to construct shared collective identities in a political environment where each side is cast as the enemy of the other. The findings indicate that in protracted conflicts, trust building is a distinct and critical process inherent in constructing a collective identity. The findings similarly reveal that while storytelling goes a long way toward establishing trust initially, ultimately, collective identity construction depends on visible confirmatory actions.