Some scholars of constitutional history suggest that the founding fathers intended Congress to take a more active role in directing combat. But an important qualification must be added. The conditions of warfare in 1787 essentially did not allow anyone other than a battlefield commander to make most basic command decisions. The naval engagements with France between 1798 and 1801 and the fighting with Britain that led to the War of 1812 occurred at a time when it often took weeks to deliver a command or learn the outcome of a battle. Under such circumstances, no Congress could dream of insinuating itself into the actual handling of a war effort. Only when the Civil War planted battles outside Washington, D.C., did Republicans in Congress seek to shame the Lincoln administration, by demanding repeated appearances of officers under the command of Gen. George B. McClellan. And even then, despite the calamitous early performance of the Union army, Lincoln strenuously resisted the attempts to erode his authority over the conduct of the war.
An incompetent executive and a disastrous war do not transform the role of Congress into military manager. Effective conduct of warfare requires hierarchical command and the ability to plan and execute effectively. Troop limits challenge this requirement, and while demands for total withdrawal are constitutional, they must proceed according to the same guideposts.
Beyond the constitutional issues, there is also a troubling policy dimension to proposals that peg troop withdrawals to dates, not events on the ground. A federal arrangement in Iraq, with oil revenues shared across regions and provinces, remains the best possible outcome there. Such an outcome might well require strategic deployment of American troops to patrol the emerging new borders, a deployment whose dimensions cannot now be calculated with any certainty. Or imagine that instead, Iraq continues its descent to genocidal civil war, and that the endgame demands the dissolution of the country. Such a disaster would not necessarily eliminate our military obligations. U.S. forces might well have to try to stem the killing of innocent civilians during a process of disorganized population transfer and border insecurity. We would not be able to escape either the practical or the moral obligation to protect vulnerable civilians. And we cannot know today what troop levels will be required to perform this role. Lest it be forgotten, Donald Rumsfeld's fetish for low troop numbers is a major reason the situation in Iraq is as bad as it is now.