Unilateral or plurilateral restrictive measures, commonly referred to as sanctions, by States or regional organizations have been acquiring an enormous practical importance in the last decades, leading also to the institution of a European Union's sanctioning mechanism of its own. In addition to that, the war in Ukraine, triggered by the Russian aggression, has given them an unprecedented visibility, including in the mainstream media. The matter nevertheless remains particularly complex, given its diverse implications from a legal as well as from an economic-financial point of view, and not least in a political perspective. This book follows up the workshop that was held at the University of Florence on 9-10 December 2021 and collects original contributions from promising or acclaimedleading experts on sanctions. This book's aim is to address key aspects relating to the use of international sanctions by assembling contributions from different fields of expertise with a view to providing readers with an interdisciplinary perspective. Insofar as possible, each part of the book (devoted to three main themes: legality and legitimacy extraterritorial implications effectiveness) consists of a dialogue between experts coming from different fields. What is the legal basis of sanctions but also how does this impact their legitimacy and the perception of their legitimacy? What are the complex implications of the extraterritorial effects that sanctions often produce or are even intended to produce? And last but not least, how effective are they and - most importantly - in relation to what underlying aims? It is hardly possible to tackle such key questions through a unique disciplinary lens. This book thus represents an invitation (to scholars, experts and decision-makers) to adopt an interdisciplinary approach that at this point can no longer be eluded.