@Perrin: albeit a very, *very* risky strategy, with lots of drawbacks. But, definitely in theory (and maybe sometimes in practice), you're right.
How about using [VortexWars](http://www.kongregate.com/games/Lopdo/vortexwars
) as inspiration? In one of their game modes, called "borders", your new armies are placed semi-randomly; territories facing enemies get reinforced first, then territories facing neutral and only after that will "internal" territories receive reinforcements. Note that for WL, internal territories will never receive reinforcements, as there is no cap on the number of armies per territory. This will also make it slightly more complicated to decide when to switch from reinforcing against real enemies to reinforcing to conquer neutrals (and this might seriously screw up in multi-attack games).
How about an option (with default on profile, overrideable per-game) "what happens when I miss my turn?". Possible values could be "turn neutral/AI (depending on game setting)", "let AI place my armies, make no moves", "let AI take one full turn in my place".