I want to know the answer to the following question:
What humanitarian concept did Montini see nationalism as violating?
All the background I'm provided with is that "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.". Is that enough to answer the question?
Answer: yes