Why were Ilkhanetes fought every neighbour of theirs? I know about mongols tengrist ideas about conquering all of known world but aren't ilkhanetes are exceptional for fighting with Golden Horde? Those both were Chinggis Khan descenders and there are rules about it.
I answered a very similar question to this in the past, you can find that post here. I can always add information if this doesn't satisfy your hunger, of course.