Some drone-strike defenders try to evade this reality. Says David Frum:

But that is nonsense.

There are quite literally hundreds of secrets here, as Senator Ron Wyden has pointed out on many occasions. If John Brennan told me all he knows about drone strikes and innocents killed in them, he could be imprisoned for years, because he'd be guilty of leaking classified secrets. In fact, he'd likely be permitted to give me the most information about innocents inadvertently killed on Afghan and Iraqi battlefields but the least information about innocents killed in the course of premeditated CIA drone strikes, where culpability for killing innocents is highest.

Marc Ambinder acknowledges the lack of accountability for unjust killings, and suggests what he thinks is a remedy.

"I don't think Congress has the wherewithal to determine, ahead of time, who belongs on a target list and who doesn't. I don't think the judicial branch would want that responsibility, especially given the time constraints that accompany the targeting process," he writes, as if the judiciary's wants rather than the nation's needs are the appropriate standard. Ambinder goes on:

What I would like to see, and what I think IS feasible, is a system of post-facto accountability. It would require more transparency by the executive branch but would not interfere with their decision-making. The lawyer or 'informed person' who signed off on the killing would be required to submit a dossier to a judge, perhaps on a special panel, who would review the decision chain and determine whether the government met its own criteria both literally and substantively. The court would release to Congress and the public redacted versions of its decisions. If it found that the president was using these powers indiscriminately, we, the people, would know. We would know well after the fact, which is a necessary evil, but we would be able to do something about it.

As I see it, the Constitution demands due process. It's right there in the Fifth Amendment. Our founding document even calls for a trial in open court when a citizen is accused of capital treason. I'll acknowledge that a presidency held accountable for the people it kills would be a huge improvement on the status quo, in which the executive branch is effectively above the law.

Any anyway, I doubt that Ambinder's alternative is available to us in practice.

Even Ambinder, in his hypothetical about a president killing people "indiscriminately," can't bring himself to say that we'd arrest, try, and imprison him. Instead, he merely says that "we, the people, would know" that he abused his power, and that "we would be able to do something about it." But would we do anything? George W. Bush abused his power. Obama has abused his power too. Everyone paying attention knows this. We're just unwilling to do anything about it. Like a misbehaving Wall Street bank that pursues short-term goals while corrupting the system to which it belongs, every presidency is treated as if it is too big to fail. After the fact, we'll always bail out presidents.