The working paper discusses the role of the judicial branch in international negotiations on the conclusion of treaties, using the situation in Germany as an example. In a first part, the author examines whether the introduction of courts into the analysis of the institutionalization of international negotiation systems is impeded, from a theoretical point of view, by the unitary actor assumption often used in international relations theory. The author doubts the explanatory power of the unitary actor assumption and denies the possibility to transfer it from the realm of international relations with its modeling approach to the non-modeling realm of law. In a second part, the paper focuses on the role of national courts in the negotiation of international agreements, which, in Germany, must in principle conform with the constitution and are subject to judicial scrutiny. Five examples of major functions of courts are analyzed: first, the theory of approximation, where the negotiation starting position is turned into a constitutionally relevant factor, allowing certain derogations from constitutional requirements; second, the margin of appreciation afforded to the executive; third, the restrictions on the transfer of power to supranational organizations; fourth, the power of interpretation; and fifth, the power of initiation. The author concludes that the influence of courts in international negotiations cannot be ignored and must not be regretted. The courts ensure that the limits of governmental action are observed, while at the same time showing a remarkable understanding of the realities of international negotiations.
