Since the mid-2010s, the collapse of key arms control treaties between great powers has unravelled the post–Cold War security architecture in Europe, heightening nuclear risks to Europe. At the same time, a fresh movement emerged, calling for the total abolition of nuclear weapons, due to their catastrophic humanitarian consequences. European policy-makers found themselves between a rock and a hard place – between the global strategic conundrum calling for growing attention to nuclear deterrence, and domestic audiences demanding just the opposite. Europe's Nuclear Umbrella is about how they navigated this balance. Building on combined insights from public administration, comparative politics, foreign policy analysis, and international relations, Michal Onderco offers a novel theory which reflects the complexity of democratic foreign policy-making in the twenty-first century.

‘This book offers a timely and compelling account of how domestic politics shapes nuclear weapons policies and policies on nuclear sharing. Focusing on a diverse set of European cases, Onderco makes a distinctive theoretical contribution and backs it with careful, wide-ranging empirical analysis. He reveals how domestic political debates, institutions, and identities are deeply intertwined with international security commitments and alliance politics. The result is a work of lasting value for scholars and students of international relations, foreign policy, and European politics.'

Gary Marks - University of North Carolina at Chapel Hill and European University Institute, Florence

‘In a moment when the debate about nuclear weapons in Europe is intensifying again, Onderco delivers the much needed candid and compelling analysis of the forces that shape both support and opposition across the continent. It is a highly recommended essential reading for policymakers and scholars alike.'

Claudia Major - German Marshall Fund

‘A valuable study of that tackles an enduring question in nuclear security: how do European governments balance global pressures to enhance nuclear deterrence by hosting nuclear weapons on their territory with domestic pressures to leave the nuclear age behind? Onderco provides a thorough and nuanced answer, bringing a wealth of original data to bear on an old question that has taken on renewed urgency in contemporary geopolitics. A must-read for those interested in security policy in Europe.'

Elizabeth N. Saunders - Columbia University

‘In this incredibly timely book, Onderco explores European support for one of the pillars of US extended deterrence to NATO: nuclear sharing. With a wealth of new data, from public opinion surveys to rich archival work to dozens of interviews with senior officials, Onderco shows how the policy of nuclear sharing has largely endured over time despite public misgivings, or outright opposition in some cases. As the European security environment deteriorates, Onderco's superb and original book shows that policy elites should be able to persist with nuclear sharing, mitigating public opinion and, if necessary, shielding the policy due to national security imperatives. This has important implications for the future of extended nuclear deterrence in NATO.'

Vipin Narang - Massachusetts Institute of Technology

‘Michal Onderco is renowned for his superb empirical work on nuclear matters and his scholarly skills to put order in the confusing complexity of this field. His book is an essential must-read contribution to a burning issue of European security, the future of nuclear deterrence and nuclear sharing.'

Harald Müller - Leibniz Peace Research Institute Frankfurt