The costs of military ventures and the attention towards human rights increases the importance of international sanctions in the twenty first century, but our knowledge is still limited in this area. The United Nations sanctions on Libya, Al Qaeda and Rwanda, or the European Union restrictive measures on the US, Transnistria and Uzbekistan are covered in the press indistinctively and the attempt to measure the effectiveness of any of these sanctions clashes against unanswered fundamental questions: what can sanctions do and when? This book undertakes an innovative approach that overcomes these problems by enhancing our understanding on how sanctions work and on explaining what we can expect from their imposition. Through the analysis of the sanctioning experience of the United Nations and the European Union after the Cold War, the investigation tests a comprehensive theoretical model and concludes that the context in which sanctions are imposed is a crucial element to explain the type of sanctions adopted. This book shakes the pre-constituted conceptions that we have on sanctions and sets the terms for more constructive debates in the future. "Francesco Giumelli's analytical distinction between the different purposes of sanctions - to coerce, to constrain, to signal - introduces an innovative way to think about and to evaluate the effectiveness of sanctions." - Prof. Thomas J. Biersteker, The Graduate Institute, Geneva "This is a thoughtful study of economic sanctions as instruments of statecraft together with other forms of statecraft in pursuit of a variety of foreign policy goals. To his credit, the author neither dismisses nor ignores signaling as a foreign policy device." - Prof. David A. Baldwin, Princeton University