Offer peace is good, but I hope its not only possible to offer your own conditional surrender, but demand the enemies conditional surrender if your are actually winning as well?
Just got remembered about this game-breaking flaw in HoI3, where for example as China its just not possible to peace out the Japanese for anything more than Manchuria. I'd happily take Manchuria, Korea, Taiwan and some pacific islands, leave them their home territory and then be best friends without having to completely break them, but you just can't do it.