This paper challenges the constructivist approaches to international relations which focus on the impact of ideas and discourse. For constructivists like Alexander Wendt, ideas and discourse can shape and constitute interests and identities. However, the author contends that, despite its recognition of the influence of ideas on the practices of states, the constructivist view is problematic, which holds that ideas are self-fulfilling prophecies that generate actions and confirm themselves in turn. By ignoring the material basis for the generation and realization of ideas and values, the constructivists put themselves into a position to be challenged. This paper challenges the constructivist approaches to international relations which focus on the impact of ideas and discourse. For constructivists like Alexander Wendt, ideas and discourse can shape and structures interests and identities. However, the author contends that, despite its recognition of the influence of ideas on the practices of states, the constructivist view is problematic, which holds that ideas are self-fulfilling prophecies that generate actions and confirm themselves in turn. By ignoring the material basis for the generation and realization of ideas and values, the constructivists put themselves into a position to be challenged.