Why did Pope Pius XI criticize Italian fascism in 1931?

In 1931, Pope Pius XI issued the encyclical Non abbiamo bisogno to denounce the Fascist regime's "pagan worship of the State" and its efforts to monopolize the lives of Italian youth.12

The conflict arose primarily because the Fascist government began curbing Catholic Action, a lay organization the Church viewed as essential for the apostolate of the laity. The regime, which viewed these youth groups as a front for anti-Fascist activity, forcibly closed them in 1931. In his encyclical, the Pope condemned the regime for a "revolution which snatches the young from the Church and from Jesus Christ, and which inculcates in its own young people hatred, violence and irreverence".132

While the Lateran Treaty of 1929 had initially fostered a period of cooperation between the Vatican and Benito Mussolini, this 1931 protest marked a significant confrontation over the regime's totalitarian encroachment on the Church's influence and moral authority.123