The International Working Union of Socialist Parties (also known as 2½ International or the Vienna International) was an international organization for cooperation of socialists. IWUSP was founded on February 27, 1921 at a conference in Vienna, Austria by ten parties (including USPD, SFIO, Independent Labour Party (Britain), Social Democratic Party of Switzerland, Independent Socialist Party (Romania), and SPÖ). The founders of IWUSP were parties that saw neither the 2nd nor the 3rd International as alternatives for affiliation. In April 1921 the Spanish PSOE joined IWUSP. The color red and particularly the red flag are traditional symbols of Socialism. ... February 27 is the 58th day of the year in the Gregorian Calendar. ... Jump to: navigation, search 1921 was a common year starting on Saturday (see link for calendar). ... Vienna (German: Wien [viːn]; Hungarian: Bécs) is the capital of Austria, and also one of Austrias nine federal states (Bundesland Wien). ... USPD election poster, 1919 The Independent Social Democratic Party of Germany (Unabhängige Sozialdemokratische Partei Deutschlands, or USPD) was a short-lived political party in Germany during the Second Reich and the Weimar Republic. ... Sfio, or Safe/Fast I/O, is an I/O library developed by AT&T Research, with several improvements over the ANSI C stdio library. ... The Independent Labour Party (ILP) was a former political party in the United Kingdom. ... The Social Democratic Party of Switzerland (also rendered as Socialist Party of Switzerland, in German: Sozialdemokratische Partei der Schweiz (SPS), French Parti socialiste suisse (PSS), Italian Partito Socialista Svizzero, Romansh Partida Socialdemocrata de la Svizra. ... The Social Democratic Party of Austria (Sozialdemokratische Partei Österreichs, SPÖ) is a political party in Austria. ... The Second International was an organization formed in 1889 (after several years of preparation) by socialist and labour parties who wished to work together for international socialism. ... Jump to: navigation, search The Comintern (from Russian Коммунистичекий Интернационал (Kommunisticheskiy Internatsional) – Communist International), also known as the Third International, was an international Communist organization founded in March 1919 by Lenin, Trotsky and the Russian Communist Party (bolshevik), which intended to fight by all available means, including armed force, for the overthrow... Jump to: navigation, search 1921 was a common year starting on Saturday (see link for calendar). ... The Spanish Socialist Workers Party (Partido Socialista Obrero Español or PSOE) is one of the main parties of Spain. ...

IWUSP criticized the other two Internationals for what it perceived to be dogmatism, and meant that more consideration should be given to the particularities of the political situation in each country. IWUSP was heavily influenced by Austromarxism. Austromarxism was the left socialist ideology pursued by the Social Democratic Workers Party of Austria during the late decades of the Austro-Hungarian Monarchy and the Austrian First Republic (1918-1934). ...

IWUSP worked for the unification of the 2nd and 3rd Internationals, something which eventually failed. In 1922 a meeting was held with delegations from the three different international bodies to discuss a merger, but unity could not be achieved and the ComIntern withdrew from the talks. In Germany in the fall of 1922, the USPD, one of the main components of IWUSP, merged with the SPD, a member of the Second International. In the spring of 1923 IWUSP merged with the Second International to form the Labour and Socialist International. Some, such as the Independent Socialist Party (Romania) refused to join the new body. The Second International was an organization formed in 1889 (after several years of preparation) by socialist and labour parties who wished to work together for international socialism. ... Jump to: navigation, search The Comintern (from Russian Коммунистичекий Интернационал (Kommunisticheskiy Internatsional) – Communist International), also known as the Third International, was an international Communist organization founded in March 1919 by Lenin, Trotsky and the Russian Communist Party (bolshevik), which intended to fight by all available means, including armed force, for the overthrow... Jump to: navigation, search 1922 was a common year starting on Sunday (see link for calendar). ... Jump to: navigation, search 1922 was a common year starting on Sunday (see link for calendar). ... Social Democratic Party of Germany (Sozialdemokratische Partei Deutschlands in German) Serial Presence Detect of computer memory modules Categories: Disambiguation ... Jump to: navigation, search 1923 was a common year starting on Monday (link will take you to calendar). ... The Socialist International (SI) is an international organisation for social democratic parties. ...

The secretary of IWUSP was the Austrian Friedrich Adler of the SPÖ. IWUSP published Nachrichten der Internationalen Arbeitsgemeinschaft Sozialistischen Parteien (News of IWUSP). Friedrich Adler refers to: Friedrich Adler (1857-1938), Czech-Austrian politician, see also German article Friedrich Adler, (1879-1960), Austrian politician, son of Viktor Adler, see also German article Friedrich Adler (1827-1908), German architect, arcaeologist, see also German article Friedrich Adler (1878-1943), artist and designer, see also German... The Social Democratic Party of Austria (Sozialdemokratische Partei Österreichs, SPÖ) is a political party in Austria. ...

Official names of IWUSP in major languages:

• Union des Partis Socialistes pour l'Action Internationale (French)
• Unione dei Partiti Socialisti per l'Azione Internazionale (Italian)
• Internationale Arbeitsgemeinschaft Sozialistischer Parteien (German)

Since IWUSP was heavily dominated by Germanic parties, the German abbreviation IASP was commonly used.