What did the president do, and when did he do it? Critics of President Obama's use of air power over Libya are posing sharp questions, with some detractors likening Obama's actions to the lawlessness of Watergate and Abu Ghraib. The detractors are wrong.
On March 19, Obama authorized airstrikes to ground Libya's planes and thereby prevent what he reasonably feared might be a massacre of Libyan civilians. Though this deployment occurred without specific congressional authorization, for centuries American presidents have unilaterally used armed forces in emergency situations. In 1962, President Kennedy used the Navy to quarantine Cuba and prevent nuclear blackmail. In 1983, President Reagan sent troops to Grenada to undo a murderous coup and protect American students on the island. In 1994 President Clinton sent the military into Haiti to restore order and prevent an international refugee crisis. By its general design and actual language, the Constitution empowers presidents to react to fast-breaking events. When bad stuff happens, Congress might not even be in session.
Counterbalancing the president's "executive power" to address emergencies, the Constitution empowers Congress to "declare war" and regulate America's armed forces. When time permits deliberation without harm to America's vital interests, only Congress can decide whether to initiate a war of choice. Presidents may nonetheless act unilaterally in small-scale ways unlikely to trigger full-blown war; and may also react unilaterally to neutralize our foes' aggressive actions when time is of the essence.
Obama's March actions plausibly fall on the presidential side of this line. Events were unfolding rapidly. Had he not acted, there could have been mass murders and a refugee crisis, destabilizing the region and mocking basic principles and institutions of international human rights. Obama acted only after both the United Nations and the League of Arab States invited the United States to help avert disaster.
But why didn't Obama ask Congress—then in session—to authorize air power in late February or early March, well before the crisis climaxed? Partly because the situation was delicate, tactically and diplomatically. Obama did not want the world to think the United States was trigger happy, and any congressional resolution that occurred before an international consensus crystallized might have made it far more difficult to persuade the world of America's benign intentions. Only after an alliance of Arab and world leaders requested America's help would a congressional resolution have been appropriate—and by then massacres seemed imminent. Thus, even when Congress is able to act quickly, it is not always able to act at just the right moment, internationally.
Beyond the Constitution, the War Powers Resolution must also be considered. Enacted in 1973, the resolution aims to clarify the line between executive and legislative power. Alas, the act obscures as much as it clarifies. Its opening section, which purports to itemize the "only" occasions for presidential unilateralism under the Constitution, oddly mentions protecting America's "possessions" abroad but not its citizens abroad. This section defines the president's powers as "commander-in-chief" but says nothing about his powers under other constitutional clauses—or powers derived from statutory implications and customary practices, which undergird what lawyers call "federal common law." This section does not use the ordinary legal language of "shall" or "shall not," and presidents of both parties have consistently treated this itemization as nonexhaustive.
Another section of the law requires presidents to report to Congress in various situations when armed forces are introduced "into hostilities" or into foreign "territory, airspace, or waters." Consistent with this section, Obama submitted a letter to Congress less than 48 hours after the Libya mission began. The report explained that U.S. airstrikes were "limited in their nature, duration, and scope," and would "set the stage for further action by other coalition partners."