The only foreign diplomatic experience Montini underwent was his time in the nunciature in Warsaw, Poland in 1923. Like Achille Ratti before him,[a] he felt confronted with the huge problem, not limited to Poland, of excessive nationalism: "This form of nationalism treats foreigners as enemies, especially foreigners with whom one has common frontiers. Then one seeks the expansion of one's own country at the expense of the immediate neighbours. People grow up with a feeling of being hemmed in. Peace becomes a transient compromise between wars." When he was recalled to Rome he was happy to go, because "this concludes this episode of my life, which has provided useful, though not always joyful, experiences."

What political problem did Montini feel he needed to address as a diplomat in Poland?