works, this time dealing with revolt—a novel La Peste (The Plague) and a play Le Malentendu (The Misunderstanding). By 1943 he was known because of his earlier work. He returned to Paris where he met and became friends with Jean-Paul Sartre. He also became part of a circle of intellectuals including Simone de Beauvoir, André Breton, and others. Among them was the actress María Casares, who would later have an affair with Camus. Camus took an active role in the underground resistance movement against the Germans during the French Occupation. Upon his arrival in Paris, he started working as a journalist and editor of the banned newspaper Combat. He continued writing for the paper after the liberation of France. Camus used a pseudonym for his Combat articles and used false ID cards to avoid being captured. During that period he composed four Lettres à un Ami Allemand (Letters to a German Friend), explaining why resistance was necessary. Post–World War II After the War, Camus lived in Paris with Faure, who gave birth to twins, Catherine and Jean, in 1945. Camus was now a celebrated writer known for his role in the Resistance. He gave lectures at various universities in the United States and Latin America during two separate trips. He also visited Algeria once more, only to leave disappointed by the continued oppressive colonial policies, which he had warned about many times. During this period he completed the second cycle of his work, with the essay L'Homme révolté (The Rebel). Camus attacked totalitarian communism while advocating libertarian socialism and anarcho-syndicalism. Upsetting many of his colleagues and contemporaries in France with his rejection of communism, the book brought about the final split with Sartre. His relations with the Marxist Left deteriorated further during the Algerian War. Camus was a strong supporter of European integration in various marginal organisations working towards that end. In 1944, he founded the Comité français pour la féderation européenne—(CFFE (French Committee for the European Federation))—declaring that Europe "can only evolve along the path of economic progress, democracy, and peace if the nation-states become a federation." In 1947–48, he founded the Groupes de Liaison Internationale (GLI) a trade union movement in the context of revolutionary syndicalism (syndicalisme révolutionnaire). His main aim was to express the positive side of surrealism and existentialism, rejecting the negativity and the nihilism of André Breton. Camus also raised his voice against the Soviet