In all cases, Inward Perfection pacifist/xenophobes. (one case w/materialist, one w/spiritual.) In this last game it was a couple of jerks with a Defense Pact that interrupted my whuppin' on the FP -- one democratic militarists, the other, slavin' jerks of one sort or another.
It seemed odd to me that they declared war, because
1) In both cases, they had a message about stopping my evil warlike threat or some such bullshit
2) In my experience, it's very rare for folks to declare a war on me while their fleet strength is 'Equivalent' to mine. In my experience, unless they have a very good reason, they wait until they have more of an advantage.
That's why I am thinking that in the end, the final trigger was me going after the FP. Which is kinda annoying! :-/ Maybe I'm wrong, though. In any case, I can handle a war on 2 fronts. 3 fronts, ugh. Not with Glavius AI, at least!