The U.S. military intervention in Libya, now in its fourth month, has brought two fundamental and recurrent constitutional questions to the fore. The first is whether the President can initiate a war, admittedly not in national self-defense or for the protection of U.S. persons or property abroad, without prior approval from Congress. The second is whether the provisions of the War Powers Resolution that require disengagement if the President has not obtained congressional sanction within two months of beginning such a war are constitutional...