The Russia-Ukraine war is a multifaceted beast. It ranges from fighting on the ground to high diplomacy, from domestic anti-war protests to international weapon supplies, from justification through sham referenda to coercion via economic sabotage, and from operational misdirection to covering up war crimes. There are close connections between these facets: the collapse of a front leads to the discovery of mass graves; the delivery of weapon systems depends on Zelensky’s appeal to the international community; sham referenda followed by annexation enable accusations of unwillingly mobilised soldiers who refuse to defend the motherland. This volume sheds light on the Russia-Ukraine war, exploring this multitude of facets and their interconnections. Bringing together the expertise of our colleagues at the Netherlands Defense Academy (NLDA) allows us to adopt a distinctively interdisciplinary approach, offering uniquely comprehensive and timely reflections on this armed conflict. The 27 chapters in this volume are centered around five themes. The first section covers historical and contemporary narratives, intelligence, digital technologies, and communication strategies. The second provides in-depth analyses of the operational aspects of the war, including warfighting on land, at sea, in the air, as well as in the space and cyber domains. The third section on international involvement covers topics such as sanctions, burden sharing, arms support and implications of the war on international institutions and the world order. The fourth provides analyses of the normative framework that applies to the Russia-Ukraine war. Finally, the fifth section deals with the way armed forces can transform their organisations and learn from this war, and concludes with questions on how and when the Russia-Ukraine war might end.