Everyone is anxious about the 16-page "white paper" that finally begins to detail the Obama administration's legal opinons on targeted assassination, but what seems to have even more people worried on the morning after — and less than 48 hours from CIA nominee and drone-program architect John Brennan's confirmation hearing — is what's missing from that argument. 

The key issue isn't that the memo authorizes the killing of American citizens in overseas drone strikes. There are plenty of human-rights activists who find that very idea deplorable, but it seems plausible that a legal framework could be created to justify killing a terrorist overseas, without violating his due process — even an American citizen. The problem with this Justice Department memo as it was presented to Congress, critics and politicians now say, is not only that it fails to make a concrete case for such an action — it doesn't even seem interested in trying. 

The essence of the memo is that if "an informed, high-level official" determines that an individual is "a senior, operational leader of al-Qa'ida or an associated force" and they post "a imminent threat" against the United States and "capture is infeasible," then wouldn't violate the Constitution to kill them. Yet, none of those terms in quotes are clearly defined, opening the door to a massive range of interpretation and wiggle room.

There are simply too many questions left unanswered by this document, leaving many advocates and even Senators to call for more answers both classified and simply witheld. Most people can't clearly define what al-Qaeda is, let alone who would be an "operational leader" of it. (And forget about choosing an "associated force.") How high does the "high-level official" have to be? Cabinet level? Lower? Could it be a general? A drone pilot? A Navy SEAL with a rifle and an unarmed terrorist right in front of him? As for the "imminent threat," the memo explicitly states that the phrase "does not require the United States to have clear evidence that a specific attack on U.S. persons and interests will take place in the immediate future." It's authorizing self-defense in a ticking-time bomb scenario — except you don't actually need the bomb.

It's important to note, however, that this "white paper" is not the beginning or end of the discussion. It's simply a declassified summation of a larger set of arguments that have passed around the Justice Department and White House counsel's office. That's why several Senators — both Democrat and Republican — have called on the president to give them the full legal opinions that have been crafted on the subject. They sent a letter to the President this week demanding a fuller explanation and even dropping veiled threats to sabotage the nominations of his new national security team in order to get them.

It's now widely assumed that one of these Senators or their staffers gave the white paper to NBC News, in order to drum up headlines about the legal issues surrounding targeted killing ahead of Brennan's hearing on Thursday. Senator Ron Wyden of Oregon has already made it clear he plans to make the drone issue the focal point of Brennan's day in front of the Intelligence Committee, and no one in the White House knows more about the issue the Brennan, who has essentially managed the drone program for the administration. He (and those legal memos) may not have the answer that Wyden or anyone else is looking for, but this latest leak will make sure he's not going to get away without having to face the questions.