Question about sp ai war declarations.
 

Well I know that when ai loses his province to some random monster raid and then I attack that province on same turn as ai does to reclaim it and I manage to win ensuing fights ai doesn't declare war.

My situation is a bit different as now ai has castle on province that random monsters raided. So can I attack province and kill defenders of castle and still get no war declared?

Re: Question about sp ai war declarations.
 

I very much doubt it. You can kill the indies fine I suspect, but storming the castle definitely seems like an act of aggression.

Re: Question about sp ai war declarations.
 

Storming castles never goes well for diplomacy. Even if you are sieging a mutual enemy, the turn that you capture the castle, the other AI player frequently takes your province and all of a sudden you're at war. It might actually be a big, but not a big one.

Re: Question about sp ai war declarations.
 

As far as I can tell it's treated as war if you attack a province the AI owned at the start of the turn. Even blowing out indies seiging a castle apparently caused a war once--I didn't want war, I wanted passage. I thought I was safe hitting the indies and moving on. I saw no war declaration but after that we were at war.