The Use and Utility of Ultimata in Coercive Diplomacy

“This nuanced, sophisticated, and pathbreaking study of ultimata from ancient times to the present explores the diverse reasons behind their issuance and mixed record of success. Sweijs examines the phenomenon of threat and escalation more generally and offers original insights relevant to the theory and practice of international relations.” — Richard Ned Lebow, Presidential Professor Emeritus at Dartmouth College, USA “This impressive work demonstrates that ultimata are far more successful than is commonly believed. This is a major and potentially troubling fi nding that makes this book a “must-read” for everyone with an interest in in coercion and coercive diplomacy.” — Peter Viggo Jakobsen, Professor at the Royal Danish Defence College Center for War Studies, University of Southern Denmark, Denmark Ultimata feature as a core concept in the coercive diplomacy scholarship. Conventional wisdom holds that pursuing an ultimatum strategy is risky.This book shows that the conventional wisdom is wrong on the basis of a new dataset of 87 ultimata issued from 1920–2020. It provides a historical examination of ultimata in Western strategic, political, and legal thought since antiquity until the present, and offers a four-pronged typology that explains their various purposes and effects: 1) the dictate, 2) the conditional war declaration, 3) the bluff, and 4) the brinkmanship ultimatum. The book yields a better understanding of interstate threat behaviour at a time of surging competition. Background materials can be consulted at www.coercivediplomacy.com. Tim Sweijs is the Director of Research at The Hague Centre for Strategic Studies and a Senior Research Fellow at the Netherlands’ War Studies Research Centre. He advises governments and international organisations and has published on international security, contemporary war, coercion, foresight, and defence planning.