Awlaki, however, is no ordinary criminal defendant. He is accused of being a senior leader in a terrorist organization that has attacked the United States and its citizens on numerous occasions. He has been "linked" to both Major Nidal Malik Hasan, the Fort Hood shooter, and Faisal Shahzad, the would-be Times Square bomber. And he was residing in Yemen in the midst of an al-Qaeda stronghold.

Had his Yemeni parents not been working in New Mexico at the moment he was born, few would question the authority of the U.S. government to conduct this operation. Since they were, however, Awlaki is a United States citizen and entitled to the same protections as any of the rest of us. What, precisely, those protections are is not quite clear in this case.

In the 1942 case Ex Parte Quirin , a unanimous Supreme Court upheld the right of President Roosevelt to try eight German saboteurs, one of whom had American citizenship, in a military tribunal. They note that "one of the objects of the Constitution, as declared by its preamble, is to 'provide for the common defense'" and note the many powers given to Congress as part of their authority to declare war and raise an army and navy and to the president as commander-in-chief. Further, they declared: "Citizenship in the United States of an enemy belligerent does not relieve him from the consequences of a belligerency which is unlawful because in violation of the law of war. Citizens who associate themselves with the military arm of the enemy government, and with its aid, guidance and direction enter this country bent on hostile acts are enemy belligerents within the meaning of the Hague Convention and the law of war."

Of course, al-Qaeda is not a country, which makes the unending global war on terror (or whatever it is we're calling it these days) murkier than World War II. But the 2006 case of Hamdan v. Rumsfeld, Boumediene v. Bush , and others have established the precedent that the post-9/11 Joint Resolution authorizing the president to "use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed or aided" the attacks constitutes a state of war. But they also held that certain due process rights are owed to those being held as enemy belligerents -- even those who aren't citizens of the United States or held on American soil. Further, while recognizing the need to "accord proper deference to the political branches" in securing the nation against terrorists, they held that "security subsists, too, in fidelity to freedom's first principles, chief among them being freedom from arbitrary and unlawful restraint and the personal liberty that is secured by adherence to the separation of powers."

There's no question, therefore, that, if the U.S. government had Awlaki in its custody, he would be entitled to due process under the Constitution. Alas, that's not the situation that obtained here. He was instead, to the extent it can be said to exist in our murky state of hostilities with al-Qaeda, on the battlefield. In this case, then, the Quirin principle that Awlaki, regardless of his citizenship, became an enemy belligerent by his association with al-Qaeda would seem to obtain. And, again, if he were not an American citizen few would question his targeting.