International Working Union of Socialist Parties
International Working Union of Socialist Parties Internationale Arbeitsgemeinschaft Sozialistischer Parteien | |
|---|---|
| Founded | 1921 |
| Dissolved | 1923 |
| Succeeded by | Labour and Socialist International |
| Ideology | Centrist Marxism Socialism |
| Political position | Left-wing |
| Colors | Red |
The International Working Union of Socialist Parties (IWUSP; also known as the 2½ International or the Vienna International; German: Internationale Arbeitsgemeinschaft Sozialistischer Parteien, IASP) was a political international for the co-operation of socialist parties.