This scholarly article examines the historical evolution and contemporary relaunch of the Action Committee for the United States of Europe between 2022 and 2026. Originally established by Jean Monnet in 1955 as an informal transnational platform to promote European integration, the Action Committee played a significant role in advancing key milestones of the European project. The paper analyses the intellectual, political and organisational process that led to the creation of the Third Action Committee, drawing on primary documents, political declarations and institutional initiatives adopted between Ventotene 2022 and early 2026. The study traces the continuity between the original Monnet Committee, its revival under Max Kohnstamm in the 1980s, and the current federalist initiative promoted by the Union of European Federalists, the Spinelli Group, the Jean Monnet Association and other partners. Particular attention is devoted to the Committee’s proposals on European defence, strategic sovereignty, Treaty reform and federal political union. The article argues that the Third Action Committee represents a contemporary adaptation of Monnet’s method to the geopolitical challenges of the twenty-first century and constitutes an important attempt to mobilise political leaders, intellectuals and civil society in support of a federal Europe.