Dimier was among the many early members of the Action Française who were practising Catholics (along with Bernard de Vésins and the and Léon de Montesquiou). They helped Charles Maurras (1868–1952) develop the royalist league's pro-Catholic policies.
In 1915, during the First World War, Dimier published Les troncons du serpent: idée d'une dislocation de l'empire allemnd at d'une reconstitution des Allemagnes in which he advocated partitioning Germany into around one hundred free cities and allocating German lands to Poland and Sweden, with the Rhineland and the Ruhr to constitute a workers' state entrusted to the trade unions.
- ‘Louis Dimier’, Dictionary of Art Historians
- Arnal, Oscar L. (1985-04-15), Ambivalent Alliance: The Catholic Church and the Action Française, 1899–1939, University of Pittsburgh Pre, p. 17, ISBN 978-0-8229-7705-6, retrieved 2017-07-27
- Jere Clemens King, Foch versus Clemenceau: France and German Dismemberment, 1918-1919 (Cambridge, Massachusetts: Harvard University Press, 1960), p. 9.