After the founding conference
At the outbreak of World War II, in 1939, the International secretariat was moved to New York, where it came further under the influence of the Socialist Workers Party. In practice it was little more than a post box during the war years after which it was returned to Europe and lodged in Paris.
In 1940, the SWP split with Max Shachtman's group forming the Workers Party, almost the same size as the remaining SWP. The split was centered around the Shachtmanites disagreements with the SWP's internal regime but in the background was their rejection of Trotsky's degenerated workers state analysis of the Soviet Union. Secretariat members who supported Shachtman were expelled, with the support of Trotsky. A new secretary, Jean Van Heijenoort (a.k.a. Gerland), was appointed.
Gerland, Albert Goldman and Felix Morrow foresaw the revival of Stalinism and social democracy after the war and argued for transitional politics in response. The SWP under James P. Cannon adhered rigidly to their interpretation of Trotsky's works, refusing to acknowledge new perspectives. They held that capitalism would suffer a major crisis after the war, resulting in a revolutionary situation. The British Revolutionary Communist Party disagreed and held that capitalism was not about to plunge into massive crisis but rather that an upturn in the economy was already underway. The leadership of the French Parti Communiste Internationaliste argued a similar position until they broke away in 1947.
The SWP viewed this as incorrect and countered by rebuilding the International Secretariat of the International with Michel Raptis (also known as Pablo), a Greek resident in France, and Ernest Mandel (a.k.a. Germain), a Belgian. They were chosen because they were not prominent in large parties, but were thought to be loyal to the SWP. Pablo became the new secretary of the International, while Mandel became its chief theoretician.
Pablo and Mandel aimed to counter the perceived deviations of the RCP and PCI, initially by replacing their leaderships. They encouraged Gerry Healy's opposition in the RCP, and in France supported elements, including Pierre Frank, Bleibtreu and Favre, opposed to the leadership of the PCI for different reasons.
The Stalinist invasion of Eastern Europe was the issue requiring most immediate theoretical investigation. At first, the International held that the USSR was still a degenerated workers' state, but that the recently invaded East European states were bourgeois entities, because revolution from above was not possible. This position was revised later as the economies of the east European states and their political regimes came to resemble that of the USSR more and more. These states were described as deformed workers states in an analogy with the degenerated workers state in Russia. The term deformed being used rather than degenerated as no workers revolution had led to the foundation of these states.
Another issue that needed to be dealt with was the possibility that the economy would revive. This was denied by Mandel, later to become a Professor of Economics, who claimed that such a revival of the economy was impossible. The leadership of the RCP (Britain) opposed this idea in a polemical article written for them by Tony Cliff entitled All That Glitters Is Not Gold. In that article he pointed out that an economic revival was already underway and that the economic perspectives of Mandel, which related to his political perspectives, were simply wrong in reality.
The Second World Congress
At the Second World Congress in 1948, Pablo and Mandel, began a turn to supporting the Tito regime in Yugoslavia. The leadership of the British RCP (led by Jock Haston and supported by Ted Grant) were highly critical of this move. By this point the FI was united around the view that the Eastern European countries were deformed workers' states. The turn to supporting Tito was none the less a fundamental change in the policies of the International as no caveats were made as to the nature of the regime in Yugoslavia and the state was described simply as a workers state.
The Congress was also notable for bringing the International into much closer contact with Trotskyist groups from across the globe. The largest groups were the Bolivian Partido Obrero Revolucionario (POR) and the Lanka Sama Samaja Party in what then was Ceylon, while the previously large Vietnamese Trotskyist groups had largely been killed by Ho Chi Minh.
The Third World Congress
At the Third World Congress in 1951, following from this, Pablo predicted an imminent Third World War, in which the Stalinists, who were seen as an anti-imperialist force, would represent the workers of the world against the imperialist camp. The logical conclusion given the tiny forces within the FI was that its groups should join (enter) the mass Communist or Social Democratic parties. This policy was known as entrism sui generis to distinguish it from the short term entry tactic employed before World War Two.
This was opposed by Bleibteu and Favre backed by Lambert, who now controlled the French section. The International leadership had them replaced by a minority, leading to a major split. All of this became too much for the forces which had initially controlled and benefited from the International. In 1953 Cannon and the SWP issued an Open Letter to Trotskyists and organised the International Committee of the Fourth International. Ths included, in addition to the SWP, Gerry Healy's group The Club, the PCI in France now led by Lambert who had expelled the Bleibtreau-Favre grouping, Moreno's group in Argentina and some even smaller groupings.
The Fourth World Congress
The parts of the International loyal to the secretariat claimed still to be the Fourth International, while groups outside called them the International Secretariat of the Fourth International. They held a Fourth World Congress in 1954 to regroup and built new sections in Britain, France and the US.
They took a relentlessly optimistic view of the immediate possibilities for the International and undertook entrism into Communist Parties where these were in power, pressing for democratic reforms, ostensibly to encourage the left-wing they perceived to exist in the bureaucracy to join with them in a revolution.
The Fifth World Congress
By the Fifth World Congress was held in 1957. Mandel and Pierre Frank looked at the Algerian revolution and surmised that it was essential to orient toward guerrilla revolutions in former colonial states. This, they held, was confirmed by the Cuban revolution. This led to a reunification with the Socialist Workers Party, who agreed on this, and left the ICFI. The fused organisation, formed in 1963, was known as the United Secretariat of the Fourth International.
See also: List of Trotskyist internationals