This lecture is composed of two main parts: the post-war condition (36-50), and the years of the splits in the FI (50-56). Bensaïd mentions Trotsky's expectation that the Second World War would be a repetition of the first in the sense that it would trigger revolutions. However, with the expectations not met, comrades had to rethink the situation after the war. Bensaïd mentions the world congress of 46 as an important moment, which brought together the leftist forces that were dispersed during the war. Bensaïd provides an international context of post-war years with a specific mention of the condition of CPs in various countries. The debates on workers' state and the future and nature of eastern countries, e.g. Yugoslavia. In the second part of the lecture, Bensaïd continues with the Years of the Splits (1950-1956), providing an in-depth contextual analysis of the international political situation during those years, with a special focus on the eastern countries, these being the main axis of international politics. The five elements that made a big impact in the world politics: "capitalism will not collapse by its internal economic conditions", consolidation of workers states, Yugoslavia-Soviet conflict, Chinese Revolution and its victory, beginning of the Korean War. These debates had effects on the building of the Fourth International in its early years and some clashes of ideas led to splits. Bensaïd specifically dwells on the Yugoslavian-Soviet conflict to discuss the condition of CPs, the Stalinisation and bureucratisation trends. He makes a omparative analysis of the Yugoslavian and Chinese CPs.