Open innovation ecosystems rely on cooperation among participating firms, but conflict also arises between participants. Yet, there is limited understanding regarding how interorganizational conflict influences ecosystem dynamics. We discuss a theoretical framework that explains how disagreements that reflect unanticipated changes in the value of contested technologies alter public, club, and private benefits for ecosystem participants and, thereby, shape their incentives to cooperate. We argue that firms are likely to increase cooperation after conflict arises when they are more technologically interdependent and have fewer outside options but otherwise are apt to reduce cooperation. Further, we propose that ecosystem participants can shape the degree of openness and the boundaries of the ecosystem to manage the implications of disagreements. Our arguments align with observations of the dear enemy recognition of cooperation among territorial biological species, which we argue also operates in organizational ecosystems.