Russia attacked Ukraine because of threats to Russian national security. The "legal framework" or "rules based order" that allowed NATO countries to create those threats to Russia created the conditions under which Russia had two choices - follow the rules exactly and let their belligerent opponents (the North Atlantic empire) continue to build up the threat level, or break the rules and protect itself.

This is why for years the conversation around Russia has been a debate between people who say a security framework must guarantee security for all, on the one side, and on the other side, people who said we only need to guarantee our security and we can threaten the security of others and they can't do anything about it.