The Use and Utility of Ultimata in Coercive Diplomacy

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.

“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 finding 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, whereby adversaries are threatened with severe punishment if they do not comply with demands, is one of the purest forms of coercive diplomacy. In this unique and meticulous study, based on a thorough data base of 87 cases, Tim Sweijs demonstrates that  ultimata can take a number of forms, each with their own conditions to determine their effectiveness.” (Sir Lawrence Freedman, Emeritus Professor of War Studies, King’s College UK) 

“In a period of intensifying rivalries, the use of coercive diplomacy, threats, and ultimatums--the "ultimata" of Tim Sweijs's fascinating new volume--will become ever more common. Tim has provided an essential guidebook to navigating these dangerous waters, emphasizing the diverse nature of coercive threats and the risks of generalized theories about them. Eloquent, deeply researched, and methodologically sophisticated, this book represents an essential contribution to our understanding of coercive threats in world politics.” (Michael J. Mazarr, senior political scientist at the RAND Corporation, USA)

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.