Sadoul's letters to Thomas soon doubled as protests against the Allied (including French) intervention in support of the anti-Bolshevik White movement. On August 28, he wrote an anti-French letter addressed to the pacifist Romain Rolland, and also taken up in the Bolshevik press. The Swiss correspondent Robert Vaucher read it and concluded: "[Sadoul] is an irreducible Bolshevist in French uniform." Nevertheless, a Swiss newspaper, "La Feuille", reprinted it, and Jean Longuet read it out in front of the delegates to the SFIO Congress in October 1918.