President Obama’s military intervention in Libya may be — barely — constitutional so far. But if the fighting continues for long or escalates, it will require congressional authorization.
Article I of the Constitution unequivocally gives Congress, not the president, the “power . . . to declare War.” The Founding Fathers sought to avoid a situation where one man had the power to commit the nation to war by himself. Even Alexander Hamilton — the biggest supporter of sweeping presidential power among the framers of the Constitution — recognized that “the Legislature have a right to make war” and that “it is . . . the duty of the Executive to preserve Peace till war is declared.”
Some small-scale uses of force may not rise to the level of a war and therefore can be undertaken by the president alone under his authority as Commander in Chief of the armed forces. President Reagan’s 1986 airstrike on Libya might be an example, as were Bill Clinton’s 1998 missile strikes against al-Qaeda base camps. If the Libya intervention remains limited to a small number of missile attacks and airstrikes, perhaps it can be justified on the same basis. However, it seems possible that the administration plans to go beyond this.
A congressional vote also might not be needed if the president were responding to an ongoing or imminent attack. However, Qaddafi has not attacked the U.S. in recent years (though he did sponsor numerous anti-American terrorist attacks in the 1980s and early 1990s) and there is no evidence that he had any immediate intention of doing so.
There is some ambiguity about exactly where a small-scale “conflict” ends and “war” begins. But the fact that we cannot draw a precise line between the two does not mean that there aren’t cases that clearly fall on one side or the other. We can’t draw a precise line between people who are “short,” those who are of “average” height, and those who are “tall.” But we can still easily recognize that Shaquille O’Neal is tall. Similarly, a large-scale military action against a foreign government clearly qualifies as “war.”
— Ilya Somin is an associate professor of law at George Mason University, where he teaches constitutional law. He writes regularly for the Volokh Conspiracy law and politics blog.