Here's a similar example. The army stack sitting on the one tile wide land is someone I have a non aggression pact with. I believe they can't go forward because of my outpost. However, they've been sitting in that spot for ~15 turns without moving. I also can not move units through now because their army stack blocks my path. Because we have a non aggression pact, I can not tell them to leave my lands. Essentially, my kingdom is cut in half by this one pissant stack.
