The 1990s saw a systemic shift from the liberal post-World War II international order of liberal multilateralism (LIO I) to a post-Cold War international order of postnational liberalism (LIO II). LIO II has not only been rule-based but openly pursued a liberal social purpose with a significant amount of authority beyond the nation state. While postnational liberal institutions helped in-crease overall well-being globally, they worked in favor of Western societies and elites and regularly violated the principle according to which alike cases should be treated alike. We argue that these institutional features of postnational LIO II led to legitimation problems, which explain both the current wave of contestations and the strategy chosen by different contestants. We develop our argument by, first, mapping the growing liberal intrusiveness of international institutions. Second, we demonstrate the increased level and variety of contestations in the areas of international security and international refugee law. We show that increased liberal intrusiveness has led to a variety of contestation strategies, the choice of which is affected by the preference of a contestant for postnational liberalism and its power within the contested institution.