So here I was thinking... finally a melite who understands!
And then I read the rest.
So let's take a quick look at the actual history of Melhed-Thalmarkin relationships: alliance for 82/~84 months, war for 2/~84 months (started by Thalmarkin for....reasons n stuff).
In my mind, the revival of good relations was not at all unthinkable (Because ya'll got exactly what ya'll set out to get, treaty n all) and in fact started when Maya accepted the peace treaty (which was totally designed to bridge the gap between the two warring peoples...not)...
.. And ended when Kalixta burnt our her duchy to the ground (only the shiny, melite bits).
Yes yes, how horrible it must seem from a Thal perspective. Simply awful.
If only Kalixta HAD starved all the regions of Agyr to nothing. At least then the whining would be validated by something. Really, ya'll should thank her for removing all traces of Melite influence. Of course, the Golden Palace is still there, but that's a minor detail.
End of the day, you have a whole new duchy, shiny from the clear-install she gave it, full of people, AND fed. It cost you a single battle and some gold. Why not just enjoy? It's done and gripping will help ya'll just as much as it helped Melhed.