r_rolo1
King of myself
I was careful with my words, Dirk: I said plot a war and not declare war 
And you forgot 2 cases:
-AP
-Events ( there is atleast one that has a insta war as a option. Neal got it in the Tokugawa version of his King of the World games )
On topic: there is another factor in AI decision of warring, that is the closeness of the target ( this unfortunately does not work very well in unmodded BtS. Better BtS AI project has a fix for it ), but there are some AI that do not take distances in consideration when deciding to go to war ( like Sitting Bull )

And you forgot 2 cases:
-AP
-Events ( there is atleast one that has a insta war as a option. Neal got it in the Tokugawa version of his King of the World games )
On topic: there is another factor in AI decision of warring, that is the closeness of the target ( this unfortunately does not work very well in unmodded BtS. Better BtS AI project has a fix for it ), but there are some AI that do not take distances in consideration when deciding to go to war ( like Sitting Bull )