Alliances and Security in Times of Aggression

This chapter examines the evolution of alliance relations in the context of a return of great power competition in the international system. It first discusses the relationship between alliances and war, before examining the challenges for alliance politics in the twenty-first century. Alliances are a key feature of the international system, and their effect on the likelihood and character of war has logically attracted a large body of scholarship. There are important discussions about two key security dynamics: war initiation and alliance commitments. Second, the security landscape has been evolving since the end of the Cold War, and new technological and economic challenges raise questions about the future of alliance management. The end of the Cold War led to the end of the Warsaw Pact. American alliances in Europe and Asia persisted, either through transformation or because their was not affected by the disappearance of the Soviet Union. One of the major questions, linked to the rise of China and Russia’s revisionist ambitions, will be whether an ‘anti-Western’ alliance between Beijing and Moscow is possible. The evolution of this cooperation and the transformation of American alliances in Europe and Asia will be decisive for the balance of forces in the upcoming strategic competition between China and the United States.