After nearly four years of failing to provide meaningful oversight of the Iraq war, it is no wonder that the newly Democratic Congress is eager to make up for lost time. Congressional proposals for reversing the course of the war are flying fast and furious. They include Sen. Barack Obama's call for a drawdown by May 2007 and a complete withdrawal by the end of March 2008, and various suggestions to amend the original authorization for the Iraq war to limit the troops to peacekeeping and fighting al-Qaida.
Given the Bush administration's generally disastrous conduct of the Iraq war and occupation, and its unrivalled claims of unilateral executive war powers, these reassertions of congressional authority are understandable. But are they constitutional? And are they wise?
The Constitution gives Congress the power to declare wars, fund them, and oversee the way they are fought. Yet the Constitution never says exactly how these powers are to be reconciled with the president's authority as commander in chief. The Constitution surely must empower the president to fight wars effectively enough to win them. That means that war must be conducted under the president's direction, not run by committee. In the modern era, no country—not even a parliamentary democracy—has been so foolhardy as to place a war under the guidance of a legislative body, rather than a single, unified command.
Many questions about the constitutional division of powers never make it to court, so we often cannot look to Supreme Court precedent to give us the answers. Historical practice cannot always be translated into practical guidance, since the nature of our government has changed almost as much as the nature of warfare over the last couple of centuries.
We are not totally at sea, however. The most influential modern Supreme Court opinion on separation of powers, Justice Robert Jackson's concurrence in the so-called Steel Seizure case, makes it clear that the realities of the modern world must be considered in tandem with institutional capacities of the different branches. The best approach to the constitutionality of the recent proposals therefore must take account of how modern war is fought. Justice Jackson's insight was that the Constitution must be read to promote the coordination of the expertise of each of the political branches, and to create a measure of constitutional distrust whenever one branch seeks to assume the responsibilities of the other.
The short answer to the question of institutional competence is that Congress is good at expressing the popular will about whether we should be at war or not, and what kind of a war it should be, while the president is good at actually fighting the war (or at least he should be). The Constitution should therefore be understood to allow Congress to declare and define the nature of the war while guaranteeing the president's authority to make decisions that are crucial to the tactical conduct of it.
In practice, that means Congress can declare that a war must come to an end. Congress can even say the conflict must be over by a specific date, as Sen. Obama has proposed. But once Congress has authorized the president to fight, it has neither the competence nor the authority to tell him which troops should be placed where on the battlefield. Nor can it order him to withdraw particular troops—or particular numbers of troops—by a specified date, as Obama's proposal, among others, would do. Finally, Congress cannot limit the number of troops who may fight.
The tactical essence of war is the decision to place some number of soldiers in a particular place at a particular time. Whoever controls that decision controls the war. To give this power to Congress would be to leave the president without true command authority over his forces and the flexibility needed to respond to military exigencies. For Congress to say how many troops must or must not be in the theater of war at a particular moment would make Congress into the effective commander in chief.
That is not to say that when Congress authorizes war, it gives the president a blank check. Just as Congress may transgress the constitutional boundary, so too may the president—and indeed, the threat to proper allocation of power comes most frequently from the executive's claim to broad emergency powers. Congress can define the laws of war. And so, the Bush administration's views to the contrary notwithstanding, it can order the president not to torture or mistreat detainees, and not to engage in certain kinds of espionage.
Just as important, Congress may specify the geographical scope of the war, limiting it to Iraq and not Iran, or Vietnam and not Laos, as it did (rather ineffectually) in the 1970s. Similarly, Congress may define the nature of a war, authorizing for example an air war but not a ground war, as it did in Kosovo, or a blockade on ships entering port but not on ships leaving port, as it did in the late 18th century during a limited sea conflict with France. Congress could tell the president that a given war should be conventional, not nuclear.
The constitutional test, in the spirit of Justice Jackson, should be whether Congress is defining the conflict in a way that makes realistic sense in the light of how modern conflict is actually fought and understood by modern combatants. It would be practically impossible for forces in Iraq to fight only al-Qaida and no one else, since al-Qaida wears no uniforms and cannot in combat be distinguished from other elements of the Iraqi insurgency. So, a law ordering our troops to fight al-Qaida and no one else in Iraq would be unconstitutionally vague, as well as unrealistic.
Finally, through the power of the purse, Congress inevitably determines the resources the president has to fight the war. If Congress has only paid for a certain number of battleships or up-armored Humvees or, indeed, troops, these are what the president will have at his disposal. But it does not necessarily follow from this that Congress can tag certain weapons for service only in one place and not in another once we are at war. Or that it can direct money allocated for troops to be used only if the troops are stateside.
In exceptional cases, Congress has in the past limited troop numbers in a particular theater, as when the Vietnam conflict came to a close. But this occurred only as part of a withdrawal of all troops, and only after a final peace treaty had been signed. In a January letter to Congress, a group of distinguished constitutional scholars argued that Congress could permissibly place a "ceiling" on the number of troops assigned to Iraq.
But in practice, specifying the number of troops comes perilously close to the kind of micromanagement by Congress that the same scholars specifically repudiated as unconstitutional in their letter.
It might conceivably be argued that adding troops in Iraq changes the nature of the war and so must trigger a new authorization of war. But the realities of this war contradict this imaginative interpretation. Troop levels have fluctuated up and down by more than 20,000 troops with some regularity since March 2003, depending upon the strategy and tactics chosen by the president and the schedule of deployment and redeployment. These fluctuations were part of a (failed) attempt to win the war, not some fundamental change in its nature or geographical scope.
Preventing Congress from capping troop levels in Iraq suggests that the president could tomorrow reassign troops from Afghanistan to Iraq—or, indeed, from Fort Bragg to Iraq—and Congress could do nothing about it. But there is nothing especially strange about this. The president does just this every day when he decides which troops will be assigned where (through the secretary of defense). What would be strange would be Congress telling the president that a particular unit must serve in Iraq or Afghanistan, or must be ordered home.
Indeed, as far as we are aware, at no time in our history has Congress claimed the right to exercise any war power beyond the following: 1) to declare, undeclare, and provide funds for war; 2) to define the field of battle and the nature of the conflict; 3) to enforce law-of-war limitations on the conduct of warfare; 4) and to demand that the president report emergency military actions to Congress for its approval within a fixed period of time.
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.