Jerry Pournelle muses about the American government's authority to assassinate American citizens.
The obvious question for discussion is whether this activity - summary execution of citizens without trial - is permissible or desirable under Constitutional Government as part of the discretionary war powers of the President, and if so, do they apply within the United States as well as in foreign nations? It is not a simple question. What acts must a citizen perform to earn a place on the proscription list? One of those killed was "Samir Khan, who edited an online magazine that spread the word on ways to carry out attacks inside the United States", but is that the totality of his acts that made him an enemy of the people? (I say enemy of the people, but I don't know what designation is given to people who may be killed on sight without trial.) What agents of the Republic are authorized to carry out the act of proscription?
Could a private citizen who somehow got wind of the fact that a given person was on the list plead that as a defense? I killed him because he is proscribed. You cannot prosecute me. (As we certainly cannot prosecute the members of Seal Team Six for the execution of Osama, although I suspect the government of Pakistan would do just that if they could get custody of the team. As for example, suppose that one of the operators of an armed drone, told to kill a certain American citizen on sight if found in Oman or Pakistan, sees that person coming out of a casino in Las Vegas and takes the opportunity to gun him down. Would that be a valid plea in Nevada? Or suppose he follows this proscribed American to federal property and shoots him the instant he sets foot on federal soil? Improbable, or course. Probably impossible, although it might make for a good novel.
The bolding is mine, and my favorite part.
I think that the "assassinations"/non-judicial killings can be justified as a component of war. If American citizens join an army that fights against America then we can kill them without trial. That's war. Is that a lot of power to entrust to the President? Yes it is. That's why we should be careful about who we elect.