The U.S. intervention in Libya’s civil war, intervention that began with a surplus of confusion about capabilities and a shortage of candor about objectives, is now taking a toll on the rule of law. In a bipartisan cascade of hypocrisies, a liberal president, with the collaborative silence of most congressional conservatives, is traducing the War Powers Resolution. Enacted in 1973 over President Nixon's veto, the WPR may or may not be wise. It is, however, unquestionably a law, and Barack Obama certainly is violating it. It stipulates that a president must terminate military action 60 days after initiating it (or...