Although many details remain unknown, we now know a little bit more than we used to about the Obama administration’s legal rationale for this shadow war. Monday night, NBC News released a 2011 Justice Department white paper on the question of whether U.S. citizens overseas can be targeted. In the process of examining that question, the paper also offers the most detailed legal theory we’ve yet seen for the shadow war more generally.

The document is 16 pages long and full of legalese, so here’s the CliffsNotes version. If you were worried about whether it was okay for the U.S. government to secretly kill an American citizen overseas, you can relax: The Justice Department says such killings are hunky dory, as long as some “informed, high-level official” decides that citizen poses an “imminent threat” and capture would be “unfeasible.”

Like many legal documents, this one does fine on its own terms, but looks a lot less satisfying when taken out of its hermetically sealed legal universe. In other words, it’s all tree, no forest — and it nicely illustrates the fact that “legality” is not the same as morality or common sense.

Let’s take the white paper’s key claims one by one. In and of themselves, each appears uncontroversial — but the sum of the parts amounts to a recipe for legally sanctioned error and abuse. (Caveat: This is a quick analysis based on an initial quick read of the memo. If a closer and more careful read suggests any errors in my analysis, I will post a revised version of this column later.)

1. American citizens overseas can lawfully be targeted and killed by the U.S. government if they take up arms in an armed conflict against the United States. True, and uncontroversial under the law of war (and under U.S. law), as far as that goes. American citizens who joined the German army during World War II could be captured or killed just like any other German soldier.

But here’s the problem. This isn’t World War II. When the “enemy” (not just a few of the enemy, but all of the enemy) wears no uniform and appears on no traditional battlefield — when there’s substantial disagreement about what it means to be a “combatant,” a “belligerent,” or to “participate in hostilities” — stating the legal principle that even U.S. citizens can be targeted if they join the enemy in a war against the United States tells us nothing whatsoever.

It restates a legal truism, without offering any criteria for determining who’s an enemy beyond stating that U.S. citizens who are “senior operational leaders of Al Qaeda and its associated forces” are targetable anywhere on the globe. But what’s a “senior operational leader”? How is that defined? How many “senior operational leaders” are out there?

And what’s an “associated force” of al Qaeda? That’s not defined either. For that matter, no criteria are offered for determining whether or not there’s an armed conflict in the first place. Is the United States in an armed conflict with, for instance, al Shabaab in Somalia? Is al Shabaab an “associated force” of al Qaeda?

2. Anyone overseas — citizen or not — who poses an “imminent threat of violent attack” against the United States can be lawfully targeted based on the internationally recognized right to national self-defense, provided that the defensive force used by the United States is otherwise consistent with law of war principles. Again, uncontroversial, as far as it goes: if someone overseas is about to launch a nuclear weapon at New York City, the United States has a perfect right (and the president has a constitutional duty) to use force to prevent that attack, regardless of the attacker’s nationality.

But once again, the devil’s in the details. To start with, what constitutes an “imminent” threat? Traditionally, both international law and domestic criminal law understand that term narrowly: to be “imminent,” a threat cannot be distant or speculative. To the Justice Department, however, “distant and speculative” are apparently perfectly consistent with “imminent”: According to the white paper, the requirement of imminence “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.” On the contrary, since “certain members of al Qaeda are continually plotting attacks…and would engage in such attacks regularly [if] they were able to do so, [and] the US government may not be aware of all… plots as they are developing and thus cannot be confident that none is about to occur,” the United States can, in effect, target anyone deemed to be an operational leader of al Qaeda or its “associated forces.” In effect, the concept of “imminent threat” becomes conflated with identity: Under this definition, any “operational leader” of al Qaeda or its “associates” is, by definition, an imminent threat.

That concept of imminence is as squishy as they come. What’s more, although the DOJ paper notes that the use of force to prevent imminent threats of violent attacks must comply with general law of war principles of necessity, proportionality, humanity, and discrimination, it offers no guidance on how to determine if a use of force is “necessary.” From a traditional international law perspective, this inquiry relates both to imminence and to the gravity of the threat itself: no one would quibble over the necessity of a drone strike targeting a terrorist about to launch a nuclear weapon aimed at New York, for instance, but a drone strike targeting a teenager about to throw a rock at a U.S. embassy would strike most people as overkill.

Here again, the DOJ document leaves the most important questions unanswered: Is any threat of “violent attack” sufficient to justify killing someone in a foreign country, including a U.S. citizen? Is every potential suicide bomber targetable? Are we justified in drone strikes against targets who might, if they get a chance, place an IED that might, if successful, kill one person? Two people? Twenty? Two-thousand? How grave a threat must there be to justify the use of lethal force against an American citizen abroad — or anyone else, for that matter? Strategically — as well as legally — it would be nice to see some suggestion that the use of lethal force on foreign soil should be restricted to circumstances in which the threat of violent attack is both imminent and extremely serious. But don’t look to this document for guidance.

3. Killing is okay if capture is not feasible. Again, fine as far as that goes — but as ever, how do we define “feasible”? What level of risk should be borne before a U.S. citizen (or anyone) is killed in circumstances that permit him no opportunity to surrender, and no opportunity to offer evidence that he has been erroneously targeted? Who determines when capture is “feasible”?

4. The determination of whether an American citizen overseas can be killed can be made by “an informed, high-level official of the US government.” Okay, would that be the president? The CIA director? The secretary of defense? The head of Centcom? The head of JSOC? An Air Force colonel? A GS-15 who works for the director of national intelligence? What’s the chain of command here? And is one “informed, high-level official” enough? What if other officials disagree? What if that high-level official’s information is wrong (cf. Iraq WMD)? What if the information is correct but the high-level official draws the wrong inferences from it? What if the high-level official abuses his power?

5. This logic poses no threat to international legal principles of sovereignty because it’s okay to use force inside a foreign sovereign state if that state either consents or is “unwilling or unable to suppress the threat posed by the individual being targeted.” This sounds reasonable until you realize it’s completely circular. I’ll restate the principle to demonstrate the circularity: Using force inside the borders of a foreign sovereign state is acceptable if the foreign state consents. If the state doesn’t consent to a U.S. strike but “an informed, high level official” of the U.S. government believesan individual in the non-consenting state poses an imminent threat of violent attack, then — by definition! — the foreign sovereign state can be deemed “unwilling or unable” to suppress the threat itself, in which case, you guessed it, the use of force is also acceptable.

6. Checks and balances are for your bank statement, not for the U.S. government. After raising — and quickly rejecting — potential constitutional arguments against the targeting of U.S. citizens overseas, the DOJ paper concludes happily that “there exists no appropriate judicial forum to evaluate these constitutional questions.” That’s because “matters intimately related to foreign policy are rarely proper subjects for judicial interventions,” and such matters “frequently turn on standards that defy judicial application.”

This is restating the problem nicely: the standards put forth in the memo are effectively standardless. They consist of sweeping generalizations about legality, but offer no criteria for actually determining legality (or necessity, or strategic wisdom, needless to say).

But that’s not a reason to reject any notion of judicial review — it’s the very reason some sort of review outside the executive branch is essential. When you have a secret, standardless process that may result in the killing of U.S. citizens, it would be comforting to have some sort of review mechanism. Ideally, it would be good to have some disinterested , informed people looking at the evidence before kill decisions are made — and this is far from unfeasible. A judicial warrant procedure like that put in place by the Foreign Intelligence Surveillance Act could be established by Congress. Failing that, an ex post review could at least highlight abuse and error, and reduce the likelihood of further error or abuse.

I’ve written before about strategic and rule of law problems posed by targeted killings (some might say I’m droning on about them). I won’t reiterate those concerns here in detail, but let’s review the bottom line: This Justice Department memo tells us that our government believes itself legally justified in secretly killing any person (citizen or not), at any time, anywhere, based on a concept of imminence that includes distant and speculative threats and also appears to include even relatively trivial threats, rather than only grave or existential threats. The definition of “enemy” is squishy, and kill decisions can be made by unidentified officials who need not reveal their information, its sources, or the criteria used in their decisions. Sovereignty poses no barriers to U.S. strikes, and no one outside the U.S. executive branch can review any killings before or after they take place. Oh, yes — and the administration officially won’t even acknowledge the existence of the targeted killing program.

I’m not inherently opposed to drone strikes or other targeted killings. I’m ready to believe that some targeted killings can be justified, legally, morally, and strategically, and I’m inclined to think that when a practice is exceptional and genuinely rare, issues of legality and the rule of law may be less urgent. But U.S. targeted killings long ago ceased to be exceptional — they’ve now become the norm, part of the new American way of war, and we can’t afford to let them remain in the legal and moral shadows.

So here’s what I want the Obama administration to tell me:

Tell me if this shadow war has any limits, and how those limits will be enforced. Tell me what safeguards there are against abuse. Tell me how I can be confident that the targeted killing process isn’t rife with error and abuse. Tell me how many targeted killings equal a war. Tell me if we’ll be expanding our shadow war into additional foreign states. Tell me if there’s any limit at all on who we can target, and when, and where. Tell me our objectives in this shadowy war. Ending the operational effectiveness of al Qaeda? Ending terrorism? Reducing anti-American violence? Tell me how we’ll know if we’re achieving our objectives. Tell me if our shadow war is making us safer, or just making our world less stable.

Tell me how this ends.

Rosa Brooks is a law professor at Georgetown University and a Schwartz senior fellow at the New America Foundation. She served as a counselor to the U.S. defense undersecretary for policy from 2009 to 2011 and previously served as a senior advisor at the U.S. State Department. Her weekly column runs every Wednesday and is accompanied by a blog, By Other Means.