Let's change the format a little. Instead of the victory condition being annihilation of the enemy, let's make it point-based. Destroying an enemy unit gets you points. Destroying an enemy building gets you a lot of points. After all's said and done, the forces can choose to retreat intact if they wish, abandoning the buildings to the other player. Or multiple players can choose to withdraw at the same time - a sort of "I'm not leaving until he leaves" deal. Perhaps some battles won't be won by annihilating the opponent, merely by doing a lot of damage to them.
Let's play a little more. Let's set it up so that tanks and such have to be manned. We'll decrease the value of a "tank kill" a little, of course, because now it's a tank-and-crew kill most of the time.
Perhaps we should add something a bit evil.
Human deaths make you lose points.
Doesn't matter which side they're on. If you kill someone, you lose points.
Of course, if it's an enemy, you might gain more points than you lose. Better be really careful of friendly fire though.
Come to think of it, we'd better add a way to surrender - to preserve what points you have left. There'll be a penalty, of course, but it might not be as big as it would be for having all your soldiers killed. And we'll need a much larger human-death penalty for killing a human who's surrendered.
Of course, if you can surrender, you can unsurrender. Perhaps a penalty, perhaps not. I suppose it really depends on whether the public hears about it. Wouldn't it be nice to add roaming camera crews? Big penalty for accidentally (or intentionally?) killing them, but human-death penalties are at a big bonus where they can see it. Some player-controlled, of course - some autonomous.
We've already got one type of civilian, how about more? Let's put in some villages. Men, women, and children, all AI-controlled of course. You could go round them up and move them out of the battlefield. They might resist. What will you do? You'll either have to spend a lot of resources training troops good enough to get them out of there without resistance, or alternatively, you could force them out.
Might have to kill one or two, but it'll be worth it in the long run - at least they won't get killed in the inevitable battle, and you could get some extra points for rescuing them. Why are we talking points? Let's rename it.
I think Popularity would be a good name.
Of course, Popularity implies a public to care about your actions, and we really haven't done anything with them yet. So let's add different nations. Say one with better technology, but a higher human-death penalty.
Or we could go the other way around. Low technology, no human-death penalty.
Congratulations. We've just made suicide bombers profitable.
It doesn't matter if they kill civilians by accident.
We could even go all the way in this direction. Low to medium technology, low resources, and profit for killing any non-affiliated human. This is what we call a terrorist.
So, can the benevolent technologists defeat the terrorists? The technologists can't catch anyone in crossfire, can't lose many people, or they practically lose straight off. The terrorists are just intent on causing as much destruction as possible. Then again, the technologists have much much better weapons and search strategies. The terrorist could surrender their units, though, and when they move in to capture to surrendered unit . . . boom.
It'd be better to shoot them on sight, whether they've surrendered or not.
You'd have to keep the camera crews out though.
I wonder how well this game would sell.