It functioned as the youth wing of the International Working Union of Socialist Parties.

February 27 - The International Working Union of Socialist Parties is formed in Vienna.

International Working Union of Socialist Parties ("2 and a half International" founded by Austro-Marxists)

His Intellectuals' Internationale therefore took distance from both the Comintern and the International Working Union of Socialist Parties.

A minority, who opposed both communism and the Second International leadership, formed the International Working Union of Socialist Parties, based in Vienna and known as the 'Second-and-a-Half International'.

From 1921 Crispien was a member of the executive board of the International Working Union of Socialist Parties and since 1923 a delegate to the Labour and Socialist International.

In 1921 the Austromarxists formed the International Working Union of Socialist Parties (also known as 2 International or the Vienna International), hoping to unite the 2nd and 3rd Internationals, something which eventually failed.

In the 1920s he was involved in organising the Vienna-based International Working Union of Socialist Parties, which united non-communist socialist parties that rejected the 'Social Patriot' leadership of the old Second International but refused to join the communist Third International.

However, some European socialist parties refused to join the reorganized international, and decided instead to form the International Working Union of Socialist Parties (IWUSP) ("Second and a half International" or "Two-and-a-half International"), heavily influenced by Austromarxism.

In other parts of Europe, many democratic socialist parties were united in the International Working Union of Socialist Parties (the "Two and a Half International") in the early 1920s and in the London Bureau (the "Three and a Half International") in the 1930s.