The politics of the IST are similar to the politics of many Trotskyist Internationals. Where it differs with many is on the question of the Soviet Union, the IST adopting the position that it was state capitalist, rather than a degenerated worker's state, and the theories of the permanent arms economy and deflected permanent revolution.
Unlike many international tendencies the IST has no formal organisational structures and has only ever made one publicly known decision, which was to expel the American International Socialist Organization from its ranks. However, the antecedents of the IST go back to the 1950s when the founders of the British Socialist Review Group (SRG), around Tony Cliff, were expelled from The Club and thus from the Fourth International. The lack of an international organization has been the source of criticism by dissident groups as the lack of a formal international democratic structure means that the leadership of the British SWP has enormous influence over the other sections without being democratically accountable.
In the 1960s the International Socialists (as the group was now called) established links with militants in a number of countries which led to the formation of IS groups in their countries. Perhaps the first such group was the Irish IS group founded in 1971, there then followed groups in Australia, Canada and Germany. Meanwhile links were built with the Independent Socialists, later International Socialists, in the USA. These links led to a split in the ISUS in 1978 and the formation of the ISO a group more closely linked to the IS Britain.
During the late 1960s the IS also attended a series of meetings held by the French Lutte Ouvriere group which were also attended by the American IS. In many quarters the IS and LO groups were seen as constituting a loose semi-syndicalist tendency within world Trotskyism in this period. The meetings were also attended by a wide variety of groups such as the Italian Autonomia Operaia but petered out.
Despite this growth there was no formal organisation. However, International Meetings of the leaderships of the IS tendency did develop, usually held in conjunction with the SWP's Marxism Summer School, which is held in London. This was the foundation of the IST which at some point in the 1990s came to be referred to thus with capitalisation.
Through the 1980s the IST grew internationally, in part as other revolutionary socialist tendencies entered into crisis thus removing competitors. New IS groups appeared in France, Belgium, Denmark, Netherlands, Norway and in Greece the Socialist Revolution Organisation which had been loosely linked to IS in the 1970s rejoined the tendency. A group of Turkish comrades was also recruited in exile during this period its members living in Germany and Britain.
The 1990s saw more international growth for the IST as groups were founded in yet more countries including Austria, Cyprus, Spain, Aotearoa/New Zealand, South Africa, Zimbabwe and Korea. Groups were also founded in the former Stalinist states as contact could be sustained in those countries for the first time, this led to the foundation of IS groups in Poland and the Czech Republic. A group linked to the IST existed in Russia but collapsed.
However, the 1990s also saw the beginning of serious problems for the IST. While there was a great deal of geographical expansion there were also losses and fragmentation. There were a number of splits which were unrelated to each other but seemed to have a common cause. Those causes were a concern among some members of the groups concerned that the internal regime of their own group had become bureaucratised and lacked in democratic accountability. Sometimes this was associated with the involvement in the internal affairs of the group by representatives of the SWP, as well as the political orientation of the group. Among the groups affected by such splits were those based in Germany, South Africa, Ireland, Zimbabwe, Australia, Aotearoa/New Zealand, Canada and France. In Belgium, the majority of the group joined the Belgian affiliate of the Committee for a Workers' International. (See entries on individual groups for details).
The last few years have seen contradictory developments for the IST. New groups have been formed in a number of countries for the first time as in Austria, Pakistan, Botswana, Lebanon, Uruguay, Finland, Sweden and Ghana. However the largest groups in the IST outside Britain have both split and sections of them have left the IST. Thus in the USA the International Socialist Organisation's leadership entered into a dispute with the leadership of the SWP as to the significance of the anti-capitalist or anti-globalisation movement following a demonstration in Seattle. This led to the ISO being expelled from the IST and a small faction leaving it to form Left Turn. Ironically Left Turn also left the IST in 2003 leaving the tendency with no affiliate in the United States. Meanwhile in Greece the OSE, which had renamed itself the Socialist Workers Party (SEK), split on similar lines with a substantial minority forming the Internationalist Workers Left (DEA).
It should be noted that the listing below is neither fully comprehensive, as there are additional groups not mentioned in official lists found on IST websites, nor completely accurate. IST sources often containing references to Suara Socialis in Indonesia and Malaysia which are in fact websites only. Many IST sources also refer to the OSI of Puerto Rico as being in the IST but it is actually close to the ISO of the USA. Some other small groups exist in various countries cannot be mentioned for legitimate security reasons. In addition there are IS type groups in a number of countries unconnected to the IST as in Germany, the USA, Australia and New Zealand. New Zealand's official group has recently triggered an international debate- Socialist Worker (Aotearoa) is part of the International Socialist Tendency. On May 1, 2007, it presented a MayDay Statement to the IST, calling for a positive engagement with the Venezuelan Revolution.
Note that the Socialist Workers Party in the United States has no formal connection to the IST nor ever has had one.
There are also a number of groups originating in the IST which hold to its basic positions but do not maintain any organizational relationship with it. These include:
Additionally there are several groups which originated in the IST but have significantly changed their political orientation. These include: