The white paper suggests that, independent of congressional authorization, the president has some amorphous reservoir of authority — created by a combination of his general Article II powers and international law (particularly the latter’s recognition of a self-defense right) — to instigate military operations on his own. The administration would comfort us regarding this imperious claim by purporting to limit it to “imminent” attack situations, and stipulating that lethal force should be used against Americans only when capture is “infeasible.” But the guidelines provide Orwellian definitions of imminence and feasibility — such that these are not really limitations at all.

What emerges instead, at least in theory, is an unbound, unreviewable license to kill any American the commander-in-chief, acting through some unspecified subordinate, decides is dangerous.

Let’s try to be more concrete about it by considering a hypothetical based on the Libya war. Obama launched that war unilaterally: There was no congressional authorization, no threat of attack against the United States, and no vital American interest imperiled. Let’s say the president or, even worse, some unidentified subordinate decided some American mercenary in, say, northern Chad (a non-battlefield) was training non-uniformed forces to conduct covert operations in support of Qaddafi. The administration appears to take the position that the president or his mysterious subordinate could legitimately dispatch a drone to kill that American citizen.

This is plain wrong. That the Constitution, as construed by the Supreme Court, abides the wartime killing of American enemy combatants is not a bright green light. It is a reluctant allowance, a grudging resolution of a very close question. The Constitution remains, primarily, every American citizen’s protection against federal-government abuse.