In a recent game, my opponent declared war on me, and in a few turns, (i was on a Duel map.) thier ships are everywhere, but almost no transports. I send a fleet of frigates to scout thier homeworld for asn invasion, and i find that there are NO SHIPS gurading it. I invade the planet and soon discover that it was thier economic, manufacturing, AND cultural hub, so they ask for peace, and I accept. A few clicks later, I win a cultural victory.
Sometimes I think this kind of thing is the game mechanics trying to move things along a little. On a good number of occasions I get the feeling that some events / wars are taking place merely to "mark time" waiting for me to get on with it - because in those instances I look back and realise I could have attacked them earlier with less pain. ie the war forced on me was one I should have had earlier had I spotted the opportunity.
Cant really adequately describe it - but if you look at many events / instances from the point of view of game balance and keeping the game moving, its surprising what you turn up. Now, when I see what seems to be a silly event I tend to immediately think "ok, what did I miss"; sure enough, its sitting there staring me in the face.
Another example - the pop up most have seen - minor civ has nicked all techs from (whoever) and will trade for a star system. Tried trading? not a chance, you could offer multiple star systems, - no go. However, get in there and take the minor civ, the techs along with it. Lets not disect that one too much, the point is I believe many instances are game mechanics, and often help you along/point out what you should have spotted earlier.
There's a danger of falling into a trap of "conspiracy theory gone mad" of course, and its certainly not true in all cases, but enough to make me suspicious and thoughtfull from a different direction/mindset when a daft event/action/instance occurs.
Regards
Zy