At the outbreak of World War I in August 1914, the Italian political left became severely split over its position on the war. The Italian Socialist Party opposed the war on the grounds of proletarian internationalism, but a number of Italian revolutionary syndicalists supported intervention in the war on the grounds that it could serve to mobilize the masses against the status quo and that the national question had to be resolved before the social one. Corradini presented the need for Italy as a "proletarian nation" to defeat a reactionary Germany from a nationalist perspective. Angelo Oliviero Olivetti formed the Revolutionary Fascio for International Action in October 1914, to support Italy's entry into the war. At the same time, Benito Mussolini joined the interventionist cause. At first, these interventionist groups were composed of disaffected syndicalists who had concluded that their attempts to promote social change through a general strike had been a failure, and became interested in the transformative potential of militarism and war. They would help to form the Fascist movement several years later.