 In Summi Pontificatus , Pius expressed dismay at the killing of non @-@ combatants in the Nazi / Soviet invasion of Poland and expressed hope for the " resurrection " of that country . The Nazis and Soviets commenced a persecution of the Catholic Church in Poland . In April 1940 , the Vatican advised the US government that its efforts to provide humanitarian aid had been blocked by the Germans and that the Holy See had been forced to seek indirect channels through which to direct its aid . Michael Phayer , a critic of Pius XII , assesses his policy as having been to " refuse to censure " the " German " invasion and annexation of Poland . This , Phayer wrote , was regarded as a " betrayal " by many Polish Catholics and clergy , who saw his appointment of <unk> <unk> as the apostolic administrator for the Wartheland in May 1942 , a " implicit recognition " of the breakup of Poland ; the opinions of the Volksdeutsche , mostly German Catholic minorities living in occupied Poland , were more mixed . Phayer argues that Pius XII — both before and during his papacy — consistently " deferred to Germany at the expense of Poland " , and saw Germany — not Poland — as critical to " rebuilding a large Catholic presence in Central Europe " . In May 1942 , Kazimierz <unk> , Polish ambassador to the Vatican , complained that Pius had failed to condemn the recent wave of atrocities in Poland ; when Cardinal Secretary of State Maglione replied that the Vatican could not document individual atrocities , <unk> declared , " when something becomes notorious , proof is not required . " Although Pius XII received frequent reports about atrocities committed by and / or against Catholics , his knowledge was incomplete ; for example , he wept after the war on learning that Cardinal <unk> had banned German liturgical services in Poland . 
