(smarter & more aggressive AI)
How do you plan to make the AI more aggressive and smarter ?
Aggressive could be done via giving it more stuff, like releasing more threat as discussed here. (Or, preventing AIP to be reduced, so it has more stuff). But smarter ?
If the player set-ups multiple choke points, the smarter idea is to siege you out, which the AI already does. That's just asking for being nuked, though. Also sieging the player kinds of fails because you don't actually need anything from the outside.
Actually, I kind of remember than in those case, one of the AI plot got some kind of teleporter thingy capable of targetting something beyond your defenses. I don't have the game at the moment, can't check. While, possibly not the right idea...
Shouldn't the game require the player to go out more ?