This introductory chapter aims to shed light on how tightly the EU and the liberal international order are entwined and discuss the likely impact on the EU of a changing and, most likely, less liberal world order. The chapter discusses the concept of order in international politics and analyses how the liberal order that emerged after WWII has effected the development of the EU. The chapter introduces the book’s interdisciplinary, holistic approach, and discusses how a changing world order is affecting the EU and how the EU, in turn, is trying to shape the emerging new order by recalibrating its policies and actions in various domains, ranging from its relations with the rest of the world, the relations among the member states and EU institutions as well as the impact of the EU’s current and future policies. Finally, the chapter highlights that the EU needs to actively defend the values and principles of liberal democracy in a changing world order.