Well, you harm them by eliminating the population along with the workforce. Now I am not saying that you should directly attack civilians, but if they are in the way, oh well.
Take for example the missles fired by the Jews unto the pallestinian civilians. People think it's so wrong, why? They're the enemy no? It makes perfect sense to me to not give a damn if civilians of the enemy get hurt.
It's the governments job to protect it's people, if the government cannot protect its citizens from war then the citizens deserve to die for picking that country.
America specifically is so concerned about civilians and I'm sure a good chunk of our military is simply helping Iraqi civilians. This is stupid, we're at war not a hospital. You see a guy with a gun pointed at you you don't sit there and debate with him, you shoot him first.
It's not inhuman, it's war, that's the price, that's the method.