against the churches, and Hitler needed to show caution. The Hitler regime responded to the ideological challenge of Christian morality using political repression and persecution and by challenging Christian teachings through education and propaganda. Some scholars, such as Richard Steigmann-Gall, argue that while there were anti-Christian Nazis, they did not represent the movement's position. Kirchenkampf Church Struggle Hitler possessed radical instincts in relation to the Nazi conflict with the Churches, and though he occasionally spoke of wanting to delay a struggle and was prepared to restrain his anti-clericalism out of political considerations, Kershaw considers that his "own inflammatory comments gave his immediate underlings all the license they needed to turn up the heat in the 'Church Struggle. According to Overy, Hitler "wanted to neutralise any political threat from organised religion ... The first step was to reach agreement with the Roman Catholic Church, whose theology was not susceptible to the new nationalist trends". Hitler dispatched the Catholic conservative Franz von Papen to negotiate a Concordat with the Vatican. He obtained an agreement that clergy would refrain from politics, in return for guarantees of Church rights. Hitler was delighted, and received the congratulations of German Catholic leaders. However, violations of the treaty began almost as soon as it was signed. Hitler promulgated the sterilization law, and began work to dissolve the Catholic Youth League. Clergy, nuns and lay leaders began to be targeted, leading to thousands of arrests over the ensuing years, often on trumped up charges of currency smuggling or "immorality". Catholic publications were shut down. The Gestapo began to violate the sanctity of the confessional. As Hitler's genocidal plans began to manifest, Catholic priests and bishops held no public protests. Instead, they prayed in support of Germany's cause, seeking to show that their support for Hitler was undiminished. By early 1937, the church hierarchy in Germany, which had initially attempted to co-operate with Hitler, had become highly disillusioned and Pope Pius XI issued the Mit brennender Sorge encyclicalaccusing Germany of violations of the Concordat and of sowing the tares of "open fundamental hostility to Christ and His Church", and denounced the pagan myth of "blood and soil". Hitler's invasion of the predominantly Catholic Poland in 1939 ignited the Second World War. Kerhsaw wrote that, in Hitler's scheme for the Germanization of the East, "There would, he made clear, be no place in this utopia for the Christian Churches". On