Really, it is designed for multiplayer. It is like Diplomacy, I don't think you will get anything interesting with the AI.
It was originally designed by a 13 year old Harry Rowland as a game for fun, remember, and not something requiring a damn PhD in nuclear physics to figure out. It is not rocket science. At the highest level, each MP is making a few fundamental choices regarding who to ally with and who to go to war with and when, subject to change at certain event points during a game and dependent on the given MP's circumstances. This is complex to a point with 6 other MPs and various alliances to consider, but not impossible. If veteran players expect newbies to be able to play and enjoy this game, then don't try to make it more difficult than it is? And if newbies can be coached (programmed?) to provide "interesting" gameplay, then an AI can be too. This isn't likely to happen soon, but I'm optimistic that eventually it can.
From some of the stories I've seen here on this forum about real human players making poor diplomacy choices, spoiling games with questionable tactics, and/or quiting mid-game for whatever reasons (and I'm referring to board game players and not pbem glitches or other issues with EiANW), I reckon the bar is set low enough for even a modest AI to prove itself capable of being a halfway decent computer opponent for a PC wargame. Perhaps even better than some average players? That should be interesting enough.