Because civilians are SUCH capable people when it comes to military decisions. I won't bother citing the mountain of examples, but in war time, let the warriors do the thinking. Its what we get paid to do. I agree though, peace time decisions should be made by those who haven't ever left its comforts.
Soldiers are paid to obey, not think.
Generals are obsessed with victory.
No, no thank you. Power should
never ever be given to the military.
You say that were it not for the civilians, the US army would have defeated the Viet Cong and NVA? Who the hell cares about victory or defeat? What made that war justified to begin with? What hurt Vietnam wasn't the civil war or the government that followed, it was the invading armies with their abusive use of chemicals like Agent Orange. For military leaders, it totally makes sense to dump a ton of herbicides to remove the hideouts of the rebels. The soviets did it too, they cut down all the trees in Afghanistan. Totally makes sense when all you care about is killing the "enemy".
