An interventionist, after the war, he joined the fascist movement, becoming the organizer of the Fascist Central Committee in Milan between 1919 and 1921.

A 4° page on letterhead of the "Fasci italiani di Combattimento, Comitato centrale di via da Cannobio di Milano," dated October 2, 1921, addressed to Dino Perrone, Compagni.

Pasella, in view of the upcoming congress of the Fasci di Combattimento in Rome, asks Perrone to meet in Ferrara on October 10th for an intimate meeting—that is, a meeting that should not be made public in order to reach agreements. In the opening of his letter, Pasella speaks of two souls within Fascism: the first tied to nostalgic memories of the past, the second inspired by the new times and the "supreme" interest of the nation. He identifies his interlocutor as belonging to "this second category." From March 1919, Dino Perrone was president of the Fascio di azione liberale of Florence. At the first Fascist convention, held in Florence in October 1919, which was also attended by Benito Mussolini, he joined Fascism. From November 7 to 11, 1921, the Second Congress of the Fasci di Combattimento was held in Rome, during which the

National Fascist Party was officially born.