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.

In this new Brookings Marshall Paper, Michael O'Hanlon argues that now is the time for Western nations to negotiate a new security architecture for neutral countries in eastern Europe to stabilize the region and reduce the risks of war with Russia. He believes NATO expansion has gone far enough. The core concept of this new security architecture would be one of permanent neutrality. The countries in question collectively make a broken-up arc, from Europe's far north to its south: Finland and Sweden; Ukraine, Moldova, and Belarus; Georgia, Armenia, and Azerbaijan; and finally Cyprus plus Serbia, as well as possibly several other Balkan states. Discussion on the new framework should begin within NATO, followed by deliberation with the neutral countries themselves, and then formal negotiations with Russia. The new security architecture would require that Russia, like NATO, commit to help uphold the security of Ukraine, Georgia, Moldova, and other states in the region. Russia would have to withdraw its troops from those countries in a verifiable manner; after that, corresponding sanctions on Russia would be lifted. The neutral countries would retain their rights to participate in multilateral security operations on a scale comparable to what has been the case in the past, including even those operations that might be led by NATO. They could think of and describe themselves as Western states (or anything else, for that matter). If the European Union and they so wished in the future, they could join the EU. They would have complete sovereignty and self-determination in every sense of the word. But NATO would decide not to invite them into the alliance as members. Ideally, these nations would endorse and promote this concept themselves as a more practical way to ensure their security than the current situation or any other plausible alternative.

In 1999, the Alliance mistakenly bombed the Chinese embassy in Belgrade. Around the same period, allegations were made regarding its involvement in human trafficking and forced prostitution in Bosnia-Herzegovina. A decade later, NATO airplanes hit a fuel truck causing significant civilian casualties in Kunduz, Afghanistan. After more than 60 years of existence and a track-record of more than 30 missions performed worldwide, it is surprising that there is still uncertainty on the scope and content of NATO’s responsibility for wrongful conduct during its military operations. This timely book deals with the international responsibility of NATO during military operations. It examines, the status of the Alliance, the existence of international obligations and conditions of attribution of conduct in NATO.

Despite momentous change, NATO remains a crucial safeguard of security and peace. Today’s North Atlantic Treaty Organization, with nearly thirty members and a global reach, differs strikingly from the alliance of twelve created in 1949 to “keep the Americans in, the Russians out, and the Germans down.” These differences are not simply the result of the Cold War’s end, 9/11, or recent twenty-first-century developments but represent a more general pattern of adaptability first seen in the incorporation of Germany as a full member of the alliance in the early 1950s. Unlike other enduring post–World War II institutions that continue to reflect the international politics of their founding era, NATO stands out for the boldness and frequency of its transformations over the past seventy years. In this compelling book, Seth A. Johnston presents readers with a detailed examination of how NATO adapts. Nearly every aspect of NATO—including its missions, functional scope, size, and membership—is profoundly different than at the organization’s founding. Using a theoretical framework of “critical junctures” to explain changes in NATO’s organization and strategy throughout its history, Johnston argues that the alliance’s own bureaucratic actors played important and often overlooked roles in these adaptations. Touching on renewed confrontation between Russia and the West, which has reignited the debate about NATO’s relevance, as well as a quarter century of post–Cold War rapprochement and more than a decade of expeditionary effort in Afghanistan, How NATO Adapts explores how crises from Ukraine to Syria have again made NATO’s capacity for adaptation a defining aspect of European and international security. Students, scholars, and policy practitioners will find this a useful resource for understanding NATO, transatlantic relations, and security in Europe and North America, as well as theories about change in international institutions.

With the increased dependence on digital and internet technologies, cyber security has come to be regarded as a national security issue, and the number of countries with a published cyber security strategy continues to rise. But these national cyber security strategies often run the risk of failing to address all the cyber security requirements of the many institutions within a given country, and the complex nature of the stakeholders involved and the networks formed by them means that the problem requires an interdisciplinary approach. This book presents papers from the NATO Advanced Research Workshop (ARW) entitled “A Framework for a Military Cyber Defense Strategy”, held in Norfolk, Virginia, USA, in April 2016. The workshop focused on key priority areas for cyber defense along with NATO’s cyber defense policy implementation and brought together experts with an eclectic mix of backgrounds and specialties from a group of NATO member states and partner countries. The participants considered not only the technical implications of cyber security efforts, but also the legal, strategic, educational and organizational aspects, and the book reflects this wide view of the field and its intricacies, highlighting the complexity of cyber security and the many challenges it presents. This overview of cyber security offers state-of-the-art approaches from a multidisciplinary standpoint, and will be of interest to all those working in the field.

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.