We live in an age of limited war. Yet the legal structure for authorizing and overseeing war has failed to address this modern reality. Nowhere is this failure more clear than in the recent U.S. conflict in Iraq. Congress self-consciously restricted the war's aims to narrow purposes-expressly authorizing a limited war. But the Bush Administration evaded these constitutional limits and transformed a well-defined and limited war into an open-ended conflict operating beyond constitutional boundaries. President Obama has thus far failed to repudiate these acts of presidential unilateralism. If he continues on this course, he will consolidate the precedents set by his predecessor's exercises in institutional aggrandizement.
The presidency is not solely responsible for this unconstitutional escalation. Congress has failed to check this abuse because it has failed to adapt its central power over the use of military force-the power of the purse-to the distinctive problem of limited war. Our proposal restores Congress to its rightful role in our system of checks and balances. We suggest that the House and Senate adopt new "Rules for Limited War that would create a presumption that any authorization of military force will expire after two years, unless Congress specifies a different deadline. The congressional time limit would be enforced by a prohibition on future war appropriations after the deadline, except for money necessary to wind down the mission.
These new rules would not only prevent presidents from transforming limited wars into open-ended conflicts; they would also create incentives for more robust democratic debate. Under the Constitution, either the House or the Senate may adopt these rules unilaterally, thereby avoiding the threat of presidential veto. Building on this constitutional foundation, our proposal provides a practical way in which Congress may effectively reassert its constitutional power-and with it more effective democratic control-over the use of military force.