The 20th century saw the rise of various politically radical and anti-clerical governments. The 1926 Calles Law separating church and state in Mexico led to the Cristero War[218] in which over 3,000 priests were exiled or assassinated,[219] churches desecrated, services mocked, nuns raped and captured priests shot.[218] In the Soviet Union following the 1917 Bolshevik Revolution, persecution of the Church and Catholics continued well into the 1930s.[220] In addition to the execution and exiling of clerics, monks and laymen, the confiscation of religious implements and closure of churches was common.[221] During the 1936–39 Spanish Civil War, the Catholic hierarchy supported Francisco Franco's rebel Nationalist forces against the Popular Front government,[222] citing Republican violence directed against the Church.[223] The Church had been an active element in the polarising politics of the years preceding the Civil War.[224] Pope Pius XI referred to these three countries as a "terrible triangle" and the failure to protest in Europe and the United States as a "conspiracy of silence".[citation needed]