"Controversy continues over the appropriate role that Congress should play in regulating U.S. military operations against foreign entities. U.S. action against Libya reignited consideration of long-standing questions concerning the President's constitutional authority to use military force without congressional authorization, as well as congressional authority to regulate or limit the use of such force. As Congress considers defense authorization and appropriations bills for FY2012, there may be a renewed focus on whether or to what extent Congress has the constitutional authority to legislate limits on the President's authority to conduct military operations in Afghanistan, Iraq, Libya, or other locations. […] The report discusses Congress's ability to limit funding for U.S. participation in hostilities, examining relevant court cases and prior measures taken by Congress to restrict military operations, as well as possible alternative avenues to fund these activities in the event that appropriations are cut. The report then provides historical examples of measures that restrict the use of particular personnel, and concludes with a brief analysis of arguments that might be brought to bear on the question of Congress's authority to limit the availability of troops to serve in ongoing military operations. Although not beyond debate, such limitations appear to be within Congress's authority to allocate resources for military operations. Portions of this report are taken from an earlier report, CRS [Congressional Research Service] Report RL33837, 'Congressional Authority to Limit U.S. Military Operations in Iraq', by Jennifer K. Elsea, Michael John Garcia, and Thomas J. Nicola."
CRS Report for Congress, R41989