Greetings, fellow galactic rulers! 

I just lost my first game in GalCiv IV: Supernova! I have been playing 4X games for thirty years, and I very rarely get out-played by the AI. Kudos to the team of GalCiv IV   So, I now wonder what my mistakes were and what I could have done better:

It was my second game of GalCiv IV, and my first against a Bright AI. I played as the Navigators on a medium sized map with two sectors. Two of my neighbors were the Festron Hunt and the Mimot Brotherhood. I didn’t do any “background checks” and just assumed the Festron Hunt were going to be trouble. 

I did a peaceful development without building much of a military fleet. I sent trade routes to my neighbors, including the Mimot Brotherhood. My plan was to have good relations with my neighbours so that I could eventually focus on the Festron Hunt. During the midgame, they declared war on me, juuust before I wanted switch to military research and ship production. Good timing by them! 

I immediately switched all my shipyards to military production. To have some breathing room, I browsed the diplomatic menu and “Proclaimed Friendship” to my neighbors, which were accepted. With the help of Artifacts, Commanders and Executive Orders, I was able to repel the Festron Hunt and recaptured my lost Colony. Eventually, I brought the war to their land (space?).

Then two things happened: First, the Thalan spawned near me and immediately declared war on me. Fortunately, they also spawned inside the Mimot Brotherhood’s borders. After I lost my strongest fleet to the Thalan, they were wiped off the map by the Mimot Brotherhood. At this point, I was still “hanging on”.

Unsuspectedly, the Mimot Brotherhood declared war on me ! This really puzzled me, because: a) they have the Pacifism ideology we had a Proclaimed Friendship c) we were trading d) we were both at war with the Festron Hunt. We only had positive diplomatic modifiers, besides the Common Border penalty. On the other hand, this was the perfect opportunity for them to strike, since my main fleet, which was protecting one of my Core Worlds near our common border, was just wiped out by the Thalan. In the end, I could not fight both the Festron Hunt and the Mimot Brotherhood. After the latter captured  one of my Core Worlds, I declared the game lost.

TL;DR: My main question is: Somewhere/somehow, could I have seen the war declaration by a Pacifistic AI coming? Is the AI always this opportunistic? Or was this a “one-in-a-hundred” situation where a Pacifist AI declares war?

Thanks for your advice!