The question of whether al-Awlaki in fact took up arms against the United States is unanswered, at least in my mind. The evidence suggests that he was very much the “bin Laden of the Internet” rather than a man at arms. What perplexes me is that so many conservatives trust the same government authorities who got it so spectacularly wrong about al-Awlaki the first time around — feting him at the Pentagon, treating him as an Islamic voice of reason — to get it right the second time around. This is not a libertarian criticism but a conservative one. It is entirely possible that the same unique strain of stupidity that led to al-Awlaki’s being invited to the Pentagon as an honored guest of the U.S. military is alive and well in the Obama administration. This is precisely why we have institutions such as the separation of powers, congressional oversight, and trials. Killing a U.S. citizen in the heat of battle is one thing, but Al-Awlaki was not killed in a battle; he was not at arms, but at breakfast. Enemy? Obviously. Combatant? Not obviously.
If we accept the rest of Krauthammer’s argument, we still need an operative definition for “taking up arms against the United States.” I have not heard a convincing one, and I have not heard a convincing case that the president should be empowered to make these decisions free of oversight from at least one of the other branches of government. Andy McCarthy’s argument that the judiciary should remain at arm’s length from question of national defense is persuasive, but our constitutional arrangements clearly demand that Congress have a substantial role in questions of war, which only Congress is constitutionally empowered to declare.