I'm not really looking for an argument, but what I was trying to get across is that sacrifice can have rewards that extend beyond the individual. In the case of individual soldiers, their death & suffering didn't seem to maximize their own personal utility. Their sacrifice, however, did buy me my freedom.
I would think that the sacrifice of the individual is very much consistent with the Darwanian view that the survival of a species is also a goal. Not so much a religious argument, as questioning at what level one measures the utility of sacrifice.