The WPR does not, as some claim, authorize presidential military action within its 60-day (or 90-day) window. But it does acknowledge an inherent presidential power to use military force within that window. As former Office of Legal Counsel chief Walter Dellinger explained in his official legal justification for the planned 1994 intervention in Haiti, the WPR, by requiring quick notice to Congress and termination after 60 or 90 days, “recognizes and presupposes the existence of unilateral Presidential authority to deploy armed forces” during that period. The WPR’s “structure makes sense,” he explained, “only if the President may introduce troops into hostilities or potential hostilities without prior authorization by the Congress.” Dellinger acknowledged that “the WPR announces that, in the absence of specific authorization from Congress, the President may introduce armed forces into hostilities only in ‘a national emergency created by attack upon the United States, its territories or possessions, or its armed forces,’ ” but noted that “even the defenders of the WPR concede that this declaration—found in the ‘Purpose and Policy’ section of the WPR—either is incomplete or is not meant to be binding,” especially since the WPR states that it is not “intended to alter the constitutional authority of the … President.”

In light of the long pattern of presidential unilateralism, Congress’ continued funding of a standing army in the face of this practice, and only very qualified restrictions in the WPR, it is hard to conclude that President Obama has acted unconstitutionally in his actions thus far in Libya. The best argument for the contrary conclusion is that no American lives or property, and no national security threat, is at stake; the Libya action seems purely humanitarian. Even if that were all it was, there are recent precedents for action, most notably Kosovo, but also Somalia, Haiti, and to some extent Bosnia. President Obama, moreover, indicated that the mission was more than humanitarian when he said that without it the “entire region could be destabilized, endangering many of our allies and partners” and the “words of the international community would be rendered hollow.” This last factor might be relevant because, as many executive branch legal opinions going back to the Korean War have maintained, the United States has a national security and foreign relations interest in effectuating the U.N. system that is implicated here, and the president may take that into account in deciding to use force.