Chapter 6 explores revolutionary world-making projects in the Global South during the Cold War, focusing on anti-imperialist movements. It begins with Fidel Castro’s 1966 call to arms against imperialism, highlighting struggles against colonialism and racism. The chapter examines the Soviet Union’s challenge to capitalism and its interaction with anti-colonial projects in Africa, Asia, and Latin America, arguing these movements were distinct and sought to repurpose legal sovereignty for Third World assertion. It contrasts socialist and liberal internationalisms, particularly in approaches to self-determination and revolutionary violence, noting the Soviet support for anti-colonial forces. The chapter discusses the influence of Marxist-Leninist thought on revolutionary movements, highlighting projects like Pan-Africanism and Cuban interventionism. It examines national self-determination’s role in reshaping global politics and the challenges new states faced in achieving true independence. The chapter concludes by calling for a re-examination of revolutionary internationalism’s impact on international law, recognising the diverse movements that sought to disrupt the Cold War order.