Up until now Southeast Asia (ASEAN) is a largely ignored area of German Foreign Policy analysis. This paper seeks to explore the German SEA-policy and its domestic origins in the interplay between government and bureaucracy. German SEA-policy is a interesting case because on the one hand there has been a number of cooperation impulses induced by the executive (esp. heads of governments), but on the other hand due to the relative marginal interest in the region the bureaucracy dominates the process over all. This could change on special occasions (Tsunami) through intensive news media coverage which increases the salience of the issue resulting in a more involved role of the executive leadership. Drawing upon the institutional based approach of Milner and the Bureaucratic Politics Model this paper seeks to develop a theoretical framework to explain the relationship between internal preference formation and the institutional setup of FP making in the interplay of government and bureaucracy and apply it to a longitudinal case study. The paper will proceed as follows: first it will explore the current German FP on SEA, followed by the development of the theoretical framework. It will then compare the German SEA-Policy of the last three coalition governments on both the decision making as well as the outcome side, which allows to analyse not only the impact of government changes and the changing dynamics of the actors involved but also the influence of the bureaucracy. The paper will finally discuss the theoretical implications for the domestic politics of foreign policy.