Re: Dishonouring Treaties.
The dishonoring treaties penalty applies regardless of the other clan's actions or any other events, I think.
Re: Dishonouring Treaties.
Ironically, as the Mori, I got rid of the Amako, then tried to annoy the Ouichi (the allies to your west) to declare on me. Then the Kikkawa declared on me, and so I then really needed to Ouichi to stay onside. Conveniently, my Daimyo under whose leadership many threats and the like had been made against the Ouichi, met an unfortunate end, and so suddenly everyone liked me again! The Ouichi are once again solid allies.
Re: Dishonouring Treaties.
Well, to update on what happened, Kikkawa didn't declare war on me at all. Even though I stole 5 provinces from them with my monk-ninja partnership. And my clan fame didn't rise as high as it should, which is good. And, when they did declare war on me (because of Realm Divide), there was no Dishonouring Treaties. So all is good. My allies, the Chosokabe, are incredibly helpful.