 Pius XII slowly eroded the Italian monopoly on the Roman Curia ; he employed German and Dutch Jesuit advisors , Robert Leiber , Augustin Bea , and Sebastian Tromp . He also supported the elevation of Americans such as Cardinal Francis Spellman from a minor to a major role in the Church . After World War II , Pius XII appointed more non @-@ Italians than any Pope before him . American appointees included Joseph P. Hurley as regent of the nunciature in Belgrade , Gerald P. O 'Hara as nuncio to Romania , and Monsignor Muench as nuncio to Germany . For the first time , numerous young Europeans , Asians and " Americans were trained in various congregations and secretariats within the Vatican for eventual service throughout the world . " 
