The main objectives of this book are to analyse the risks and dangers NATO faces in the current strategic environment and to discuss how the alliance can readjust to those challenges. How can NATO adapt to the dangerous combination of a revisionist Russia, a reluctant United States, and a Europe in crisis? NATO's relevance and ability to survive have been challenged many times before, and it has not only survived but also has proven highly adaptable to change. This has been good for Western cohesion and for the consolidation of the liberal-democratic, rules-based world order. The main argument of this book is that NATO can overcome this latest set of challenges as well and retain its central role as a cornerstone of the European and transatlantic security order. NATO is different from other alliances because its members share not only interests but values as well, codified in the preamble of the North Atlantic Treaty as allied support for democracy, individual liberty, and the rule of law. The greatest enemy of the alliance is the forces that challenge the common norms and values of NATO's member states, and – in a larger perspective – the liberal-democratic, rules-based world order, and Western civilisation itself. The book makes an original contribution to the existing literature on NATO and transatlantic relations and discusses the latest developments within NATO since the Trump administration took office. The book will be of much interest to students of NATO, geopolitics, security studies, and International Relations in general.