Rustic--while you do bring up an interesting point about technology, I think it ignores the basic fact that in most military jobs you are in fact a rifleman first (whether the service agrees or not). The Navy might be the exception, since they are not likely to be attack by ground forces in the middle of the ocean, but they have equally arduous duty, that requires them to maintain a minimal level of fitness. That is my position, fitness. It doesn't matter how carefully you train, if you are training hard enough to be in relatively decent enough shape to go to war, you will most likely suffer lasting injuries (most likely through accidents). Add to that the marginal medical care received at military hospitals and the formula for lasting physical injuries is developed. I had the saying while in, that I really didn't want to serve past 20 years, only because my body wouldn't last that long. At this point I know I was and still am on track to wanting to call it quits after 20 years, not likely to happen since I'm not in the military any longer, but I still have to maintain a high level of fitness. That level of fitness is becoming more and more painful to maintain due, in part, to some of the injuries I suffered while serving.
I would have no problem with the government going to a retirement program for the military similar, if not the same, to the 6(c)/12(d)retirement offered to federal civilian law enforcement, fire fighters, other high risk federal jobs. It allows for 25 and out, or 20 years service and I think it's 52 years old. I don't know what the difference in cost would be, but I don't think the military members should have to pay for the pension side of it.