A country wins wars by having great generals; what is the purpose of a general officer in command of an army or army group? To win. He alone should have complete control over how to do that including selecting the best strategic, operational and tactical strategies and COAs. Since WWII the executive branch has refused to permit this, first just for nuclear matters, but eventually for nearly everything; the civilian leadership makes the strategic decisions, and many of the operational decisions, and even suggests/approves the tactical operations. If you want to win wars, you let generals fight them their way, with their own ROEs and with the full support of the executive branch. If this were the case, the people back home could not influence war plans once congressional approval for declaration of war occurs (another thing that is necessary and omitted from each conflict since WWII).
This sounds good and I have often said this myself. Think about Gen. Wesley Clark and the many like him. The problem is that the military has become too much like other government and civilian bureaucracies. Generals are survivors. Often the ones who have risen to the top are just good at politics. They are afraid of risk and they are hyper-concerned with political correctness.