How International Law Obligates: International Identity, Legal Obligation, and Compliance in World Politics

All political leaders represent the political authority of the state and are committed to state sovereignty. Yet some are also moved by a sense of perceived international legal obligation and defer to international legal rules and institutions. Why do some politicians develop a sense of legal obligation and defer to international law while others do not? This dissertation seeks to explain the psychological logic of legal obligation. Legal obligation entails a tension between commitment to the sovereign authority of the state and deference to international law, and imposes psychological “sovereignty costs” upon politicians. I explain the psychological logic of legal obligation by analyzing the effect of international superordinate identification on the resolution of this tension. My central claim is that political leaders’ degree of international identification critically shapes their sense of legal obligation by affecting the perceived legitimacy of international law’s authority. I argue that international identification, through the causal mechanism of reference group membership, prompts politicians to re-conceptualize their countries as members of the international community rather than view statehood separate from membership in the society of states. International identification helps actors assimilate state-concept into the prototype of international community member, shift their understandings of the state’s legitimate duties to the international level, and associate sovereignty with recognized member status rather than with supreme decisionmaking authority. As a result of these transformations, international identification ii increases the perceived legitimacy of international law’s authority, influences how politicians process the psychological “sovereignty costs” involved in legal obligation, and thus conditions actors’ ability to reconcile commitment to sovereignty with deference to international law. Therefore, I argue that the variation in individual levels of legal obligation is created by the strength of international identification. High international identifiers view deference to international law as a responsibility of membership in the international community, and thus could balance sovereignty with deference with relative ease, leading them to form a strong sense of legal obligation. Low international identifiers perceive deference as loss of sovereign capacity, and thus lack a viable sense of legal obligation. I also analyze the relationship between legal obligation and compliance. I posit that a strong sense of legal obligation strengthens politicians’ compliance resolve by acting as a self-imposed constraint and by heightening their sensitivity to social pressure to uphold international law. Therefore, legal obligation increases an actor’s propensity to favor compliance even when compliance is costly. Employing survey and experimental methods, I test for the effect of international identification on the degree of legal obligation as well as examine the direct influence of legal obligation on compliance preferences. I evaluate my hypotheses both in the context of European Union law and international law. Using data from an original survey of German Parliamentarians and laboratory experiments, and employing quantitative methods of analysis, I find a systematic relationship between international identification and legal obligation strength. I further discover that a strong sense of legal obligation raises the threshold of compliance cost tolerance and increases compliance resolve. iii To My Family & For KaroŞ