 Pius warned the Allies of the planned German invasion of the Low Countries in 1940 . In Rome in 1942 , US envoy Myron C. Taylor , thanked the Holy See for the " forthright and heroic expressions of indignation made by Pope Pius XII when Germany invaded the Low countries " . After Germany invaded the Low Countries during 1940 , Pius XII sent expressions of sympathy to the Queen of the Netherlands , the King of Belgium , and the Grand Duchess of Luxembourg . When Mussolini learned of the warnings and the telegrams of sympathy , he took them as a personal affront and had his ambassador to the Vatican file an official protest , charging that Pius XII had taken sides against Italy 's ally Germany . Mussolini 's foreign minister claimed that Pius XII was " ready to let himself be deported to a concentration camp , rather than do anything against his conscience . " 
