Why did Jean-Paul Sartre criticize the French Communist Party after the Hungarian Revolution?

Jean-Paul Sartre’s criticism of the French Communist Party (PCF) was triggered by the 1956 Hungarian Revolution. When the Soviet Union sent tanks into Budapest to suppress the uprising, Sartre was deeply disillusioned, as the event shattered his hopes for the promise of communism.1

In his article "Le Fantôme de Staline," published in Les Temps Modernes, Sartre condemned the Soviet military intervention. Crucially, he also attacked the PCF for its blind submission to the dictates of Moscow, arguing that the party failed to act independently or account for concrete, existential circumstances. This experience led Sartre to conclude that the Soviet form of Marxism had become ossified. He argued that instead of respecting individual freedom and adapting to specific historical situations, the party forced reality to fit a rigid, predetermined universal. This shift in perspective eventually informed his development of a more independent "Sartrian socialism," as explored in his work Critique of Dialectical Reason.1