International law remains in many ways a challenge to legal science. As in domestic law, the available options appear to be exhausted by either internal doctrinal approaches, or external approaches applying more general empirical methods from the social sciences. This article claims that, while these major positions obviously provide interesting insights, none of them manage to make international law intelligible in a broader sense. Instead, it argues for a European New Legal Realist approach to international law accommodating the so-called external and internal dimensions of law in a single more complex analysis which takes legal validity seriously but as a genuinely empirical object of study. This article constructs this position by identifying a distinctively European realist path which takes as its primary inspirations Weberian sociology of law and Alf Ross’ Scandinavian Legal Realism and combines them with insights originating from Bourdieusian sociology of law.