[Sammas]

I find that the AI is actually quite good for this kind of game, considering its quick response time. Also the target market is not 100% hardcore strategy gamers.

Judging from what I've seen, I think the AI is probably searching the game tree a few ply deep, and choosing the best move based on some pre-defined valuations. That's why it isn't good at long-term strategy, and why it sometimes goes for cities/capitals when it doesn't have a chance at holding them for long enough to capture.