This book comes out at a time of grave uncertainty about the content and the very existence of international legal restraints on the use of force, in the international community as well as among legal scholars. The time is therefore ripe for an in-depth analysis on the methodological issues which constitute the basic bricks on which the legal discourse about the state of the law must be built. By offering the result of an open and frank discussion about the methodology of determining the law on the use of force "at a time of perplexity", this timely book constitutes an invaluable contribution to legal analysis.