Game Operators should not deal with in-game politics. We should be focused on players cheating or breaking the Terms of Service or Game Rules.

My personal opinion on the issue is that if players (or Kingdoms) consistently break their word, then they shouldn't be trusted. Deal with them instead of trusting them and don't let them get into a position where breaking their word is advantageous for them because you already know they will do what's best for them and not uphold their agreements.