with his rejection of religious authority as a tool of oppression and his strategy of "patently explain," Soviet leader Joseph Stalin energetically pursued the persecution of the Church through the 1920s and 1930s. Lenin wrote that every religious idea and every idea of God "is unutterable vileness... of the most dangerous kind, 'contagion of the most abominable kind". Many priests were killed and imprisoned. Thousands of churches were closed, some turned into hospitals. In 1925 the government founded the League of Militant Atheists to intensify the persecution. The regime only relented in its persecution following the Nazi invasion of the Soviet Union in 1941. Bullock wrote that "A Marxist regime was 'godless' by definition, and Stalin had mocked religious belief since his days in the Tiflis seminary". His assault on the Russian peasantry, wrote Bullock, "had been as much an attack on their traditional religion as on their individual holdings, and the defense of it had played a major part in arousing peasant resistance . . . ". In Divini Redemptoris, Pius XI said that atheistic Communism being led by Moscow was aimed at "upsetting the social order and at undermining the very foundations of Christian civilization": The central figure in Italian Fascism was the atheist Benito Mussolini. In his early career, Mussolini was a strident opponent of the Church, and the first Fascist program, written in 1919, had called for the secularization of Church property in Italy. More pragmatic than his German ally Adolf Hitler, Mussolini later moderated his stance, and in office, permitted the teaching of religion in schools and came to terms with the Papacy in the Lateran Treaty. The Western Allies saw the war against Hitler as a war for "Christian Civilisation",Franklin D. Roosevelt, American Labor Day Address, 1 September 1941 while the atheist Stalin re-opened Russia's churches to steel the Soviet population in the battle against Germany.Geoffrey Blainey; A Short History of Christianity; Viking; 2011; p.494 The Nazi leadership itself held a range of views on religion. Hitler's movement said it endorsed a form of Christianity stripped of its Jewish origins and certain key doctrines such as belief in the divinity of Christ.In 1937, Hans Kerrl, the Nazi Minister for Church Affairs, explained "Positive Christianity" as not "dependent upon the Apostle's Creed", nor in "faith in Christ as the son of God", upon which Christianity relied, but rather, as being represented by the Nazi Party,