International Courts' de facto Authority: Between Legitimacy and Pre-emption

Abstract

One of the central theoretical puzzles that surround international courts and tribunals relates to the interplay between their factual and legitimate authority. Domestic courts' factual authority seldom comes in question, and it is its justification which creates conceptual challenges. The situation is reversed in regard to international courts. Because they are voluntary authoritative institutions, their legitimacy is far less of a concern than the factual weight they have in shaping actors' conduct. This reversed dynamics between de facto and de jure aspects of authority generates a peculiar jurisprudential challenge. Whereas the criteria of legitimate authority are widely shared and established, the criteria of what it means to be a factual authority are much less visible. The paper discusses one of the recent accounts of the factual authority of international courts offered by Alter, Helfer, and Madsen, who link it to international courts' effective audience. They submit that what matters for measuring the de facto authority is how far-reaching international courts' rulings are in terms of audience, rather than motives and beliefs of the relevant actors. I argue that this perspective overlooks the normative nature of authority, which is not confined to justification issues only. I submit that the degree of the factual authority of international courts reflects in how successful they are in pre-empting practical reasons. Even though international courts always claim that their rulings are pre-emptive, their actual pre-emptive force may vary. Thus, a more pre-emptive ruling makes it less appropriate to invoke and rely on the underlying practical reasons, and vice versa.