Pope Francis is a bit of an idiot. The logic in these types of arguments is bizarre. "NATO goaded", "Moscow views", "complex", "NATO ultimately started", "were warned", all utter bullshit.
One country attacked another in a bid for total domination. It IS simple, Russia and Putin are 100% wrong. How hard is it to reason this out? It scares me a little that people can't. The aggressor is the one who sends their soldiers across the border and starts killing people. Putin and Russia did that. Ukraine and NATO did not, end of debate.
NATO did not "recruit" those Eastern European countries! Those countries ran to NATO for protection as fast as they could as soon as they could because they understand Russia, especially under Putin, is a violent aggressive power. They were just proved they were right 100%!
Just because Moscow has views or warned doesn't make it right even 1% never mind enough to start murdering people. If I ordered Shane Ralson to stop writing articles because I felt they threatened me and you didn't stop could I attack you violently? Of course not! If some students came to your lectures instead of mine could I attack you violently? Of course not! This is not difficult moral reasoning.