This open access volume surveys the state of the field to examine whether a fifth wave of deterrence theory is emerging. Bringing together insights from world-leading experts from three continents, the volume identifies the most pressing strategic challenges, frames theoretical concepts, and describes new strategies. The use and utility of deterrence in today’s strategic environment is a topic of paramount concern to scholars, strategists and policymakers. Ours is a period of considerable strategic turbulence, which in recent years has featured a renewed emphasis on nuclear weapons used in defence postures across different theatres; a dramatic growth in the scale of military cyber capabilities and the frequency with which these are used; and rapid technological progress including the proliferation of long-range strike and unmanned systems. These military-strategic developments occur in a polarized international system, where cooperation between leading powers on arms control regimes is breaking down, states widely make use of hybrid conflict strategies, and the number of internationalized intrastate proxy conflicts has quintupled over the past two decades. Contemporary conflict actors exploit a wider gamut of coercive instruments, which they apply across a wider range of domains. The prevalence of multi-domain coercion across but also beyond traditional dimensions of armed conflict raises an important question: what does effective deterrence look like in the 21st century? Answering that question requires a re-appraisal of key theoretical concepts and dominant strategies of Western and non-Western actors in order to assess how they hold up in today’s world. Air Commodore Professor Dr. Frans Osinga is the Chair of the War Studies Department of the Netherlands Defence Academy and the Special Chair in War Studies at the University Leiden. Dr. Tim Sweijs is the Director of Research at The Hague Centre for Strategic Studies and a Research Fellow at the Faculty of Military Sciences of the Netherlands Defence Academy in Breda.

Future NATO looks at the challenges facing NATO in the 21st century and examines how the Alliance can adapt to ensure its continued success For more than 70 years, the North Atlantic Alliance has helped to preserve peace and stability in the Euro-Atlantic area. It has been able to adjust to varying political and strategic challenges. We must ensure that NATO continues to be effective in the future. This requires looking ahead, challenging habitual approaches, exchanging ideas, and advancing new thinking. I highly recommend Future NATO to policymakers, military professionals and scholars alike, as it offers necessary critical and constructive analysis of current and future challenges posed to our security and defence.Annegret Kramp-Karrenbauer, Minister of Defence, Germany Since 1949, NATO has successfully upheld common principles and adapted to new realities. As Future NATO examines, the Alliance is facing a new set of external and internal challenges in the decades to come. The Alliance and its partners need to remain committed to future changes. I recommend this excellent study to all, but especially to the younger generation of scholars and future policymakers. Trine Bramsen, Minister of Defence, Denmark Over the last 70 years, Europe has lived in peace and prosperity because of NATO, with unity as our most important weapon. We may have our differences, but we will continue to work on our common cause to promote peace, security and stability. To effectively do so, NATO needs to continuously adapt to changing security situations. An important current challenge is to ensure European Allies take more responsibility for their security. But we also need to look at future challenges and find innovative solutions for them. Future NATO offers a useful analysis that can help us prepare for what is to come for the Alliance. Ank Bijleveld, Minister of Defence, The Netherlands

A review of the full range of recent official and non-official schemes for improving NATO's conventional posture, from exploitation of emerging technologies to non-provocative defences, in the light of prevailing military, political, economic and demographic trends.

Are NATO’s mutual security commitments strong enough today to deter all adversaries? Is the nuclear umbrella as credible as it was during the Cold War? Backed by the full range of US and allied military capabilities, NATO’s mutual defense treaty has been enormously successful, but today’s commitments are strained by military budget cuts and antinuclear sentiment. The United States has also shifted its focus away from European security during the wars in Afghanistan and Iraq and more recently with the Asia rebalance. Will a resurgent Russia change this? The Future of Extended Deterrence brings together experts and scholars from the policy and academic worlds to provide a theoretically rich and detailed analysis of post–Cold War nuclear weapons policy, nuclear deterrence, alliance commitments, nonproliferation, and missile defense in NATO but with implications far beyond. The contributors analyze not only American policy and ideas but also the ways NATO members interpret their own continued political and strategic role in the alliance. In-depth and multifaceted, The Future of Extended Deterrence is an essential resource for policy practitioners and scholars of nuclear deterrence, arms control, missile defense, and the NATO alliance.

"Russia's recent aggression against Ukraine has disrupted nearly a generation of relative peace and stability between Moscow and its Western neighbors and raised concerns about its larger intentions. From the perspective of the North Atlantic Treaty Organization (NATO), the threat to the three Baltic republics of Estonia, Latvia, and Lithuania -- former Soviet republics, now member states that border Russian territory -- may be the most problematic of these. In a series of war games conducted between summer 2014 and spring 2015, RAND Arroyo Center examined the shape and probable outcome of a near-term Russian invasion of the Baltic states. The games' findings are unambiguous: As presently postured, NATO cannot successfully defend the territory of its most exposed members. Fortunately, it will not require Herculean effort to avoid such a failure. Further gaming indicates that a force of about seven brigades, including three heavy armored brigades -- adequately supported by airpower, land-based fires, and other enablers on the ground and ready to fight at the onset of hostilities -- could suffice to prevent the rapid overrun of the Baltic states"--Publisher's web site.

The emergence of the European Security and Defense Policy (ESDP) in the last two-thirds of the 1990s and continuing into the new century, has been a complex process intertwining politics, economics, national cultures, and numerous institutions. This book provides an essential background for understanding how security issues as between NATO and the European Union are being posed for the early part of the 21st century, including the new circumstances following the terrorist attacks in New York and Washington on September 11, 2001. This study should be of interest to those interested in the evolution of U.S.-European relations, especially in, but not limited to, the security field; the development of institutional relationships; and key choices that lie ahead in regard to these critical arrangements.