AI diplomacy is very weird.

In my Rome game it's the second century BC and the Romans rule the western Mediterranean, the Ptolemies the eastern. The Ptolemies keep attacking me in Rhodos and then offering a cease-fire a turn later. I can demand Antiocheia in return and get it for free, and I even demanded their entire western seaboard (Antiochea, Tarsos, Damascos, Hierosolyma, Alexandria, Sidon, Bostra, Edessa) and I got it in return for a few 100.000 minai. I then reloaded because it didn't make any sense to me for them to sell their empire after a war that had seen 1 skirmish fought. And all this is on hard campaign difficulty.