Aimed at scholars, practitioners, and advanced students in comparative public law, this edited volume offers an up-to-date and globally framed exploration of the principle of proportionality in contemporary constitutional systems. Bringing together contributions from experts across Asia, Europe, and North America, it examines how proportionality functions as a tool for balancing fundamental rights and public power, particularly in the context of recent global emergencies. The three regional sections provide a comparative overview of diverse constitutional traditions, highlighting how courts and legislators have adapted proportionality in response to states of emergency and to the growing relevance of socio-economic rights. Through its broad geographical scope and coherent analytical focus, the volume provides readers with a valuable guide to understanding how modern constitutional orders confront the challenges of crisis governance.