This seems to demonstrate to me that this code is based only on societal norms and not anyting else at all.

1: Do not harm pregnant women. (Period.)

2: Thou shalt not kill: except in justice. (Killing other human beings is only permitted if they are doing or have done something that the socity deems heinous enough that allowing it to continue is worse than murder. In almost all cases being part of or suporting "the enemy" falls into this catagory.)

3: Thou shalt not steal: except in justice. (Stealing is considered wrong, unless the person stolen from has violated social conventions with respect of obligation to help the broader socity with their wealth and accomplishments, then they become a valid target.)

4: Do not harm children without good cause. (Good cause in this case can sometimes be stretched quite far. The obvious example is that of parental discipline, but sometimes things like child slavery are justified thus saying things like "at least they have food and somewhere to sleep.")

5: Do not do to others what you would not wish them to do to you.*
* Unless they have made themselves acceptable targets by violating social convention.

I don't think that's an unfair assessment. I'd argue that morality is based on relationships (for religious people, that includes relationships with God). An individual with no relationships has no need of morality. Because society is nothing but a web of relationships (and war is the intentional destruction of those relationships) it would make sense that a 'universal morality' applies "only" to socialized people, and perhaps does not apply to war-time.