Friendly AI declares war, no vassal or master

[Tatran]

I was totally caught by surprise.
This must have happened.
I have a permanent alliance with Montezuma.
Washington hates Montezuma, but is friendly with me.

 

[alexman]

I can't see the problem from the screenshots. Can you explain better, and perhaps attach a save? A friendly AI can certainly declare war on your team, especially if he hates your teammate.

 

[Tatran]

In trade negotiations with single leaders, the leaders of a permanent
alliance show up together. You can't make a deal alone with one of them.

http://forums.civfanatics.com/uploads/20970/Victoria_AD-1784.CivWarlordsSave

 

[alexman]

Sorry, I'm a bit slow.
I still don't understand the problem. Could you explain in detail, from the beginning?

 

[Tatran]

This problem is harder to describe than I thought.

Washington is Friendly in the next picture, but the "we don't like you enough"
message indicates he is using other relation modifiers. The same thing for
declaring war. But, as shown in the picture, he's willing to trade a tech
with me individual, using the relation modifiers between him and me.
Now, he doesn't see me as a team, but he's helping Montezuma, his worst
enemy, this way too.
He also traded with Asoka and Wang Kon individual, but if I want to stop
Washington trading with one of them, he'll stop trading with both
of them and not individual.

 

[alexman]

I understand now. Thanks.
Although it is working as designed, so it's not really a bug.
The AI attitude towards a team is an average of their attitude towards each member.

 

[Tatran]

Another problem is the following situation :

Cyrus was once a vassal of Montezuma.
Montezuma didn't cancel that deal after Cyrus broke away from him.
Now Montezuma is my permanent ally, I can't cancel the deal as speaker
of our team and I can't make Montezuma cancel the deal.