The Communist Manifesto in specific countries in the mid-nineteenth century such as France, Switzerland, Poland, and Germany, this last being "on the eve of a bourgeois revolution", and predicts that a world revolution will soon follow. It ends by declaring an alliance with the social democrats, boldly supporting other communist revolutions, and calling for united international proletarian action—Working Men of All Countries, Unite!. In spring 1847 Marx and Engels joined the League of the Just, who were quickly convinced by the duo's ideas of "critical communism". At its First Congress in 2–9 June, the League tasked Engels with drafting a "profession of faith",
Ventotene Manifesto future wars. Vayssière notes that the manifesto is widely seen as the birth of European federalism. Spinelli (1907–86), a former Communist, became a leader of the federalist movement due to his primary authorship of the Manifesto and his postwar advocacy. The manifesto called for a break with Europe's past to form a new political system through a restructuring of politics and extensive social reform. It was presented not as an ideal, but as the best option for Europe's postwar condition. The most important assessment was the assertion that This statement was in contrast with the idea, then prevailing, that unity