Of the organizations listed, two claim to be the originalFourth International founded in 1938: the reunifiedFourth International (USFI) and theInternational Committee of the Fourth International (ICFI). The Fourth International split into two factions 1953 over the question of historic perspective, with the International Secretariat (ISFI) turning in favour ofdeep entryism and supporting petty-bourgeois nationalist movements in less developed countries, and the International Committee (ICFI) upholding the need to form revolutionary parties. The factions reunited in 1963 resulting in the formation of reunified Fourth International (USFI), while parts of the ICFI did not. Both the USFI and ICFI went on to fragment further, giving rise to several new internationals.
Certain organizations which claim to be Trotskyist make no attempt to claim any relationship to the Fourth International in an organizational sense and argue that it no longer exists. Some claim to represent a continuity from the Fourth International or to have re-established it: for example the Fourth International (ICR) International Centre/Center of Reconstruction, also known as the FI (La Verité), also calls itself the "Fourth International".
The various organizations listed here range in size from those having thousands of adherents in dozens of countries to tendencies which can barely claim a dozen members in three or four countries.
Revolutionary Communist International, split from CWI in 1992. Previously named International Marxist Tendency (IMT) (2004–2024), and the Committee for a Marxist International (1992–2004)[1]
Liaison Committee for the Reconstruction of the Fourth International (CERCI), founded by the Bolivian party POR which broke off with the original Fourth International in the 1950s.[16]
Organising Committee for the Reconstitution of the Fourth International (OCRFI), split from the defunct Fourth International (ICR) in 2016. The latter was formed after a split from the ICFI in 1972.[24]
International Trotskyist Committee (ITC), founded by former members of the defunct Trotskyist International Liaison Committee in 1984. The latter was founded by expelled members of the ICFI in 1974.[25]
Liaison Committee for the Fourth International, founded by former members of the ITC.[26][27]
^INTERNATIONAL SOCIALIST ALTERNATIVE EDITORIAL BOARD (8 February 2020)."International Socialist Alternative Launched".International Socialist Alternative. International Socialist Alternative. Retrieved28 October 2020.
