Actually, that Civilization IV mod that I keep yammering on presented an interesting idea to me. If we managed to completely 100% automate warfare, for all sides of the conflict, then it could possibly create some sort of weird pacifism/ war fusion.
On the one hand, such a policy would mean that (theoretically) non-voluntary civilian casualties should be close to zero (barring a few accidents) although what happens to those citizens once they surrender (because they know that the robots will blow them to bits otherwise) is a whole different debate (civics I guess, since the war is technically over).
Additionally, non-civilian casualties would be much lower, due to most of the crime being fought by drones and missiles and robots and over computer networks. Robots can't do everything we can, but given enough time, they'll be able to do a whole lot-- enough that we could basically just have to command them from afar, with occasional interventions from actual humans who must be on the battlefield out of necessity, but a good deal of the threat to their well-being would be counter-acted with defensive automated stuff.
Also, a lot more money would be spent on technology rather than training, housing, supplying, etc. human troops since a better-developed firewall that makes your robots much harder to hack than your opponents, or the development of a better production method for machine parts, or the creation of a more-efficient microprocessor that would let the troops make judgements and follow orders more quickly would be much more helpful to a war effort (and can only be brought about with people putting their minds to science, math, engineering, and programming) than the number of human troops that could be "bought" with the same amount of grant money required to develop said technologies.
This idea's a bit less solid, but possibly, since "the face of war" would now be scientists, mathematicians, etc. plus robots, drones, etc. plus politicians, bureaucrats, strategists, etc. rather than soldiers and victims of war, then war itself will seem slightly less inhumane and it would be slightly harder for countries to paint each other as villains when both sides are doing practically the same thing, and it's robots that are doing most of the fighting.
Lastly, it would enable truly pacifist societies to defend their countries while (theoretically) never killing another human, since it would likely be possible to focus entirely on defensive measures without risking their own-well being, but at the same time, defending themselves in a way that does not promote or reward actions of suffering or cruelty, since the "greater good" would no longer require such measures.
I'm sure there's more than a few shaky points in this idea, but I find the idea fascinating, and I hope that if we can't achieve world-peace, and this doesn't lead to bad things that I haven't realized yet, then I think this would be a next-best solution that at least has more than just a very tiny chance of happening, even if that chance was still relatively small.