What would it take to get the Mongols to invade India and hold it? I've got a timeline in my head where a strong Persian Empire is still standing, which would stop the Mongols from getting deep into the Middle East and result in them moving against India instead. Is that the kind of thing it would take to make the Mongols mount an invasion of India, or is there some POD after Genghis emerges that would result in the same thing?