The International Communist Party (ICP) is a left communist international political party which is often described by outside observers as Bordigist, due to the contributions by longtime member Amadeo Bordiga. The strongest base of the ICP remains Italy, where it was founded, but the Party also has sections in other countries.
A clearly left current, the Sinistra, emerged at the Italian Socialist Party’s (PSI) Congress of Milan in opposition to the reformist leadership of the party and the trade unions, and soon took a leading position in labor struggles. This Left, the Sinistra, made clear its internationalism by strongly opposing the Italo-Turkish War (1911), and organized itself nationally as the Intransigent Revolutionary Faction at the Reggio Emilia Congress of 1912. A similar conflict broke out in the Socialist Youth Federation against those who wanted the body to become largely a culture-dispensing organization. By the Sinistra, both party and Young Federation were seen as organs of struggle. The militant youth were to receive their revolutionary inspiration and stamina from the whole life and experience of the party as it guided the working class on the road to revolution, and not from some banal “party school” education. Amadeo Bordiga (1889–1970) and the “Revolutionary Socialist Club Carlo Marx” of Naples were decisive influences amongst the Intransigent Revolutionaries, and have remained fundamental references points in the history of the Sinistra.
With World War I the Sinistra proclaimed the need for revolutionary defeatism, which was in full agreement with Vladimir Lenin’s theses, hardly known at the time in Italy. With a background tragically highlighted by the failure to oppose the war when most Socialist parties voted war credits and solidified with their respective national bourgeoisie, the PSI, notwithstanding the efforts by the Sinistra, approved an ambiguous slogan, “neither support nor sabotage,” which meant no support for the war, but no fight against it either. With Benito Mussolini at their head, the interventionists had earlier abandoned the party.