Eighty interviews with bureaucratic and political actors in five national capitals illustrate the Keohane/Nye theoretical argument concerning the importance of transnational and, specifically, transgovernmental factors in world politics. Focusing upon the development and application of integrative techniques between countries which have no formal supemational integrative institutions, the paper reports on the practice of transgovernmental politics within the dyad of Canada and the United States, and the triad of Denmark, Norway, and Sweden. Dealing both with middlelevel bureaucratic practitioners concerned with horizontal coordination of policy and administration between countries, and with bureaucratic and political actors responsible for the cohesiveness of national policies, the paper explores situations in which the demands of external and domestic harmonization are inconsistent, and sometimes mutually contradictory. The problem of maintaining “dual coherence” in domestic and external policy and administration is identified, and procedures for attempting such coordination are discussed. Of importance are modifications within the traditional institutions of inter-state communication: foreign offices and embassies. Recommendations are made on the basis of the intra-North American and intra Scandinavian experiences. It is suggested that considerable insight into managing policy and administrative areas which are neither purely domestic nor purely external may be gained by the study of bureaucratic experience only infrequently considered by students or governmental managers. Insights which may be gained from such study, it is argued, may be of great relevance in dealing with the challenge which transgovernmental horizontal harmonization now poses for national administrations.