So I went and beat up Gandhi, took three of his cities including Delhi and one which I razed. He is now bottom score and pretty much out of the game, but refuses to make peace with me, even though I have 100 warscore. He had a defensive pact with Kamehameha who I've already made peace with (won that war, took gold etc) as well. War has been going for about 38 turns at this point, what are some possible reasons that he's refusing peace?