He became a journalist and a poet and was involved with the integralist and monarchist journal Action Française, but turned towards the Left after the Spanish Civil War (1936–39).
In February, they organised the distribution of 10,000 propaganda flyers, but one of the distributors was caught by the police, leading to the arrest of d'Astier's niece and uncle.
D'Astier was one of the founders of the Stockholm Committee; he denounced the Soviet Union leadership under Nikita Khrushchev after the crushing of the Hungarian uprising, and broke ties with communists.
His brother, Henri d'Astier de la Vigerie, was from the far right, and, initially a member of the Action Française, may even have been involved with the Cagoule terrorist group.
Family friend Joan Baez wrote and recorded a song, "Luba the Baroness", about learning of the death of the oldest son, Jean-François.