You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Pope_Paul_VI

Context:
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."

Question:
What type of political stability was compromised as a result of violent nationalism?

Peace