In this book, I examine how Swiss courts, but also domestic courts in general, do and must interpret international law. For this purpose, I analyze whether they comply with what international law requires from States when they interpret their international legal obligations. I also assess whether Swiss courts’ interpretations are predictable, clear, and consistent. I then suggest how to improve this domestic judicial practice from these two perspectives.
The two basic claims guiding my study are the following. First, Switzerland and other States, when interpreting international law via their organs, including their courts, must abide by the interpretative methods required by international law. They must use these methods as guides in their interpretative process. Indeed, courts’ adherence to the law’s interpretative methods is a condition of the legality of their decisions. Second, courts, qua legal reasoners, must interpret the law as predictably, clearly, and consistently as possible. The predictability, clarity, and consistency of domestic courts’ interpretations of international law matter because these virtues support legality. Said virtues also matter because they influence the extent to which domestic judgments constitute reliable and helpful means for ascertaining international law.
