Yeah this happened to me as Poland - vassalized Livonian Order, who dragged me into a war with Sweden, which Austria refused a Call to Arms for. Fortunately my opinion of Austria was high enough that it didn't take long for him to offer an alliance again, and the war allowed me to beat a few things out of Sweden, but if Austria hadn't been so interested in restoring the alliance then I would've lost my only strong ally.
Given that Austria was so keen on allying again, there must just be something that's coded improperly that makes allies always reject. It's not like he'd have to declare on a powerful friend - relations were neutral and Sweden was weak and far away.
Also, could we remove the "my country thinks this or that, about other country" it doesn't really make any sense ? as I am a person, not an AI (i hope)
Maybe you could think of it as what the populace/nobles think of the other country? That's how you make sense of relations between countries in a PU. If your people hate another country then maybe it'll be harder to ally since your troops will refuse to fight alongside them or something like that. Granted, this would make more sense if you got, say, a stability penalty from allying with a country your people don't like, but I guess it's better than nothing? They got rid of the attitude modifiers for human players early on, which was my main problem, I can deal with the rest.
