As a veteran I agree with you about doing what it takes to keep soldiers alive.
However, engineering a person who sleeps only 2 hours a night is not something that can be done with popping a pill. I have my concerns about pill popping soldiers anyway, but engineering implies a redesign of the human body, or gentics, not a quick battlefield fix.
If the military were to chose to employ only people who were engineered to sleep 2 hours per night they would quickly build a very elite warrior class. It doesn't take a lot of hard thought to see the pitfalls with that. What if the military identified people before birth for re-engineering? Is that moral? How safe are we with a class of warriors waiting to go to war?
Just some food for thought.