The PCE and its Catalan referent, the United Socialist Party of Catalonia, had already been committed to the liberal possibilist politics of the Popular Front during the Spanish Civil War. The leader of the PCE, Santiago Carrillo, wrote Eurocommunism's defining book Eurocomunismo y estado (Eurocommunism and the State) and participated in the development of the liberal democratic constitution as Spain emerged from the dictatorship of Franco. The Communist parties of Great Britain, the Netherlands and Austria also turned Eurocommunist.
Western European communists came to Eurocommunism via a variety of routes. For some it was their direct experience of feminist and similar action. For others its was a reaction to the political events of the Soviet Union, at the apogee of what Mikhail Gorbachev later called the Era of Stagnation. This process was accelerated after the events of 1968, particularly the crushing of the Prague Spring.
The politics of détente also played a part. With war less likely, Western communists were under less pressure to follow Soviet orthodoxy yet also wanted to engage with a rise in western proletarian militancy such as Italy's Hot Autumn and Britain's shop steward's movement.
Eurocommunism became a force across Europe in 1977, when Enrico Berlinguer of the Italian Communist Party (PCI), Santiago Carrillo of the Communist Party of Spain (PCE) and Georges Marchais of the French Communist Party (PCF) met in Madrid and laid out the fundamental lines of the "new way". The PCI in particular had been developing an independent line from Moscow for many years prior, which had already been exhibited in 1968, when the party refused to support the Soviet invasion of Prague. In 1975 the PCI and the PCE had made a declaration regarding the "march toward socialism" to be done in "peace and freedom". In 1976 in Moscow, Berlinguer, in front of 5,000 Communist delegates, had spoken of a "pluralistic system" (translated by the interpreter as "multiform"), and described PCI's intentions to build "a socialism that we believe necessary and possible only in Italy". The compromesso storico ("historic compromise") with Democrazia Cristiana, stopped by Aldo Moro's murder in 1978, was a consequence of this new policy.
The collapse of the Soviet Union and the end of the Cold War put practically all Leftist parties in Europe on the defensive, and made neoliberal reforms the order of the day, many Eurocommunist parties split, with the Right factions (such as Democratici di Sinistra or Iniciativa per Catalunya) adopting social democracy more whole-heartedly, while the Left strove to preserve some identifiably Communist positions (Partito della Rifondazione Comunista or PSUC viu/Communist Party of Spain).
Other critics point out the difficulties the Eurocommunist parties had in developing a clear and recognisable strategy. They observe that Eurocommunists have always claimed to be different - not only from Soviet Communism but also from Social Democracy - while, in practice, they were always very similar to at least one of these two tendencies. Thus, critics argue that Eurocommunism does not have a well defined identity and cannot be regarded as a separate movement in its own right.
From a Trotskyist point of view, Ernest Mandel in From Stalinism to Eurocommunism: The Bitter Fruits of 'Socialism in One Country' views Eurocommunism as a subsequent development of the decision taken by the Soviet Union in 1924 to abandon the goal of world revolution and concentrate on social and economic development of the Soviet Union, the so-called "Socialism in One Country". Thus the Eurocommunists of the Italian and French Communist parties are considered to be nationalist movements, who together with the Soviet Union abandoned internationalism. This is analogous to the Social democratic parties of the Second International during the First World War, when they supported their national governments in prosecution of the war.
From an Anti-Revisionist point of view, Enver Hoxha in Eurocommunism is Anti-Communism views Eurocommunism as the result of Nikita Khrushchev's policy of peaceful coexistence. Khrushchev was accused of being a revisionist who encouraged conciliation with the bourgeoisie rather than adequately calling for its overthrow. He also stated that the Soviet Union's refusal to reject Palmiro Togliatti's theory of polycentrism encouraged Communist parties to moderate their views in order to join cabinets, which in turn forced them to abandon Marxism-Leninism as their leading ideology.
More generally, from the point of view of most revolutionary left-wing movements, Eurocommunism simply meant an abandonment of basic communist principles, such as the call for a proletarian revolution, which eventually led many Eurocommunists to abandon communism or even socialism altogether (by giving up their commitment to overthrow capitalism). Such critics felt strongly vindicated when several Eurocommunist parties scrapped their communist credentials following the fall of the Soviet Union.
More rhythmic criticisms of Euro Communism were presented by the poet John Cooper Clarke, in 'Euro Communist/Gucci Socialist.'