Political psychology and social constructivism exist in an “ideational alliance” against realism; however, both have overlooked behavioral conditioning, the basis of animal learning. Through six stages situated in international negotiation behaviors, the theory of Conditioning Constructs shows how behavioral conditioning can take parties from specific to diffuse reciprocity, rationalist to constructivist cooperation, and crisis to durable peace. In stages 1, 2 and 3, parties use negotiated agreements to exit prisoner’s dilemmas, continuously reinforce cooperation during agreement implementation, and satiate to rewards as initial implementation finalizes. In stages 4, 5 and 6, parties receive fresh rewards with new negotiations, undergo intermittent reinforcement with periodic agreements thereafter, and finally attribute cooperative behavior to actor constructs. Conditioning Constructs demonstrates that agency is possible in socially constructed structures through willful participation in conditioning through negotiation; and that, while Anatol Rapoport’s tit-for-tat strategy is suited to initial cooperation, intermittent reinforcement better preserves late-stage cooperation.