Perhaps the most cherished cliche of American political discourse is that politics “ends at the water's edge,” that domestic partisan battles should be put aside when dealing with important international questions. This principle, however, is honored more in the breach than in the observance. Despite such lofty sentiments, foreign policymaking in democracies remains intensely political. The study of relations between democracies, therefore, cannot ignore domestic politics or the essential domestic actors, political parties.

The alliance between the Federal Republic of Germany and the United States of America has been one of the keys to the postwar international system. Although both partners recognize its “existential” significance, the details of the alliance have been subject to constant negotiation, with political parties in the center. In both the Federal Republic and the United States, structures and practices have favored the executive in foreign affairs. In the United States, the “imperial Presidency,” exercising the expanded powers that came with the New Deal and World War II, sought maximum freedom from legislative interference. In the Federal Republic, Chancellor Konrad Adenauer quickly established his semiauthoritarian “chancellor democracy” (Kanzlerdemokratie). This did not mean, however, that legislatures became irrelevant. Although it was possible to make initial decisions without legislative consent, it remained necessary to defend those decisions before the electorate. To make their case, governments relied on political parties to frame the issues and garner public support.