In August 1985 the National Committee of the Democratic Socialist Party (then called Socialist Workers Party) voted to end the DSP’s affiliation to the Fourth International, the main international organisation of Trotskyist parties. The two articles in this pamphlet explain the reasons why this decision was taken. They are based on reports adopted by the DSP National Committee, in October 1984 and August 1985, respectively. The first, by then DSP National Secretary, the late Jim Percy, explains why the DSP no longer considers itself a Trotskyist organisation. The second, by DSP National Executive member Doug Lorimer, explains why the DSP decided to leave the Fourth International. The DSP’s decision to end its affiliation to the Fourth International culminated a process of rethinking within the DSP about many of the ideas it had shared in common with other Trotskyist parties. This process of rethinking the politics and perspectives of Trotskyism was stimulated by the 1979 victory of the Nicaraguan Sandinista National Liberation Front and by the increasing impact the Cuban revolution, and its vanguard, the Cuban Communist Party, has had on Latin American and world revolutionary politics.