Machiavelli is considerably shorter than Diplomacy, IME, and suffers much less from the problem that eventually stopped me playing it - you lose, are out of the game and then have nothing to do for four-six hours while the mid-game and endgame are played out. In Mach the first player knocked out signals the beginning of the endgame - a winner is probably only an hour away.

Britannia or Maharaja might prove interesting - pretty much at the A&A level, but some real player interaction/diplomacy involved. Days of Decision II (played alone, without WiF) might appeal as a very much more political kind of WWII game than A&A, but there are some major rules problems with DoD alone which require a lot of clearing up - it makes *much* more sense if you have played WiF5 a few times.

On political games, Kremlin is tremendous fun and very quick.

Remember that there were very few wars with more than two sides, so most wargames that are multi-player are team vs. team rather than A v B v C. If you're happy to play in teams against each other, then there are lots of wargames that might appeal - try The Russian Campaign (certainly playable three or four a side). Most East Front games can be played like this.

American Civil War games can often be played two-a-side (one running the West, the other the East) - the new For The People uses a fair- ly straightforward system, especially if you've played We The People or Hannibal first. Successors (same system, but I've not played it yet) is multi-player and sounds like a lot of fun.