War makes friends

[ViterboKnight]

A strange behavior during my last game. Playing at Monarch, with Isabella (BTS v3.13).
Mehmet, although in good relations with me, declared war on me and fought for several years, and eventually accepted a peace declaration.
After few turns, he showed up again proposing a trade, and his relations were still GOOD, even after a war! It was not later than 10 turns after our war!! And no bad note or "minus" signs on our relations history (like "-3, this war spoils our relations" or similar. I don't know how it's written in English, I play the Italian version).
How is it possible??

 

[Sempronio]

"This war spoils our relationship" goes away once you sign the peace treaty.
After the war relations go back to the pre-war situation unless you were the one declaring war (declared war on us penalty) or raze some of his cities.
If you declare on a leader that is pleased with you it's quite possible that he'll be pleased again after the war ends.
Maybe the AI leaders take the war as a chance to eliminate all his political opponents .