This Introduction begins by outlining what is meant by international relations. It then tells the story of how and why the academic study of international relations emerged in the early twentieth century before considering the need to ‘globalise’ the study of international relations – to make it an academic discipline more open to non-Western perspectives. It sketches the changing agenda of international relations, a shift that some scholars describe as a transition from international relations to world politics or from the ‘traditional’ to the ‘new’ agenda. Although there is little doubt that, as political reality has changed, new theoretical tools have become necessary to grasp it, we should not assume that the myriad changes in our world have rendered the ‘traditional’ agenda obsolete. As we shall see, the ‘new’ agenda supplements, but does not supplant, the ‘traditional’ agenda. It is now more important than ever to consider the relationships between ‘traditional’ and ‘new’ agendas, and to globalise IR.

This chapter introduces students to the rich and controversial legacy of Marxism and one of its major offshoots in the twentieth century, Critical Theory. The chapter is presented in two parts. The first part touches on the historical and intellectual context that ‘created’ Marxism, Marx’s notion of historical materialism and the issue of how Marx’s ideas have been received in IR. The second part concentrates on the two strands of Critical Theory that have emerged within IR: one derived from the so-called Frankfurt School and the other from Italian thinker Antonio Gramsci.

This chapter introduces the principal actor in international relations: the sovereign state. First, it defines the state. Second, it explores the origins of the state in the transition from the medieval to the modern world. Third, it examines the concept of sovereignty, especially as it was articulated in early modern political thought. Fourth, it surveys different historical explanations of how the sovereign state triumphed over alternative forms of political society. Finally, it outlines some of the continuing debates about the modern state.

Until quite recently, international relations theory neglected the role of emotions. This chapter surveys the rehabilitation of emotions and moral sentiment in political and international relations theory with a view to examining the cultivation of sympathy as a normative and historical condition of international humanitarian law as a ‘civilising process’. The chapter argues that, as part of a broader ‘civilising process’ to alleviate unnecessary human suffering, moral sentiment has been an indispensable, if ambivalent, factor in the historical pursuit of humanitarian action. The chapter argues that the modern codification of international humanitarian law is predicated on the cultivation of moral sentiments such as sympathy and compassion being extended to those injured or killed on the battlefields.