Summary of the thread until now:

Crono: If it is ok to kill soldiers it is ok to kill civilians. And vice versa. gjm: But wait there are important differences between soldiers and civilians. Soldiers kill and are often willing to be killed. We should consider these distinctions in evaluating this issue. Crono: Civilians are part of the war effort too and are willing to help in killing. (Adding after my comment: Collective punishment is a good tactic!) Me: Some people aren't part of the war effort. Protesters, children. Crono: If killing children prevents suicide bombers, do it. Also, look at these other cases where we should kill civilians.

You've given some arguments for why you think killing civilians is good strategy in some circumstances. But I don't see how this answers the issue gjm brought up. Even if there are circumstances in which killing civilians in justified it doesn't follow that reasons for killing soldiers are good enough reasons to kill civilians. It seems like the fact that soldiers are more willing to die and that they are likely to kill if they aren't killed first are very good reasons for requiring weaker justifications for soldier killing than civilian killing. Why is gjm's point wrong?

Also, as this is a discussion about international law the question is about setting norms for war fighting. As such, do you think collective punishment and killing the children of soldiers to deter them make sense as norms governing conduct during wars?