Does the NDAA Authorize Detention of US Citizens?

[THIRD UPDATE (12/9/11): See here for my updated assessment as to US citizens captured abroad.] [SECOND UPDATE (12/7/11): Thanks to a flood of emails and calls, I am aware that a great many readers remain unaware that the Senate bill was amended after my original post below, in a manner that explicitly states that the NDAA should not be read as affirming or prohibiting citizen detention.  I've written this post to explain exactly what this would mean.] [UPDATE: As most readers know, the Senate subsequent to my post below adopted an amendment speaking directly to this issue.  A post noting this development appears here already, but I've been encouraged by some readers who do not normally follow this blog to include this update in this post in order to avoid confusion.  So, to be clear, what follows below is my original post from the morning of the 1st, reflecting the bill as it stood *before* the Senate adopted the Feinstein compromise.] I gather that there has been some confusion as to whether S. 1867, the NDAA bill currently pending in the Senate, should be read as (i) requiring the use of military detention for US citizens in some circumstances, (ii) authorizing it but not requiring it, or (iii) precluding it.  The best reading of the language currently in the bill is (ii): Section 1031 and 1032 when read in conjunction suggest that US citizens are included in the grant of detention authority contained in section 1031, while being expressly excluded from the language in section 1032 that appears on the surface to affirmatively requires resort to detention for a subset of the persons made detainable by section 1031. Here is why this is confusing: S. 1867 originally contained language to the effect that citizens are not subject to detention solely to the extent forbidden by the Constitution.  Put simply, that was a backwards way of saying that citizens are subject to detention, except of course where the constitution forbids it.  That drew lots of heat, and the language was altered.  Now, in the current bill, things work as follows: First, section 1031 is the explicit grant of detention authority.  It no longer says anything about US citizenship, one way or the other.  It is just like the AUMF in that respect.  Of course, we need to recall that the Supreme Court in Hamdi had no trouble concluding that insofar as the AUMF provided detention authority for persons captured in combat in Afghanistan, that authority extended to US citizens (Hamdi left open the question whether the AUMF provided detention authority to other contexts, and if so whether citizenship would remain irrelevant in those other contexts).  In any event, against this backdrop, section 1031 as currently written--and if examined in isolation--would not alter the somewhat uncertain status quo regarding the availability of detention for citizens.  But 1031 does not stand in isolation.  Consider section 1032. Section 1032 is the supposedly-mandatory military detention provision—i.e., the idea that a subset of detainable persons (“covered persons” in the lingo of the statute) are not just detainable in theory, but affirmatively must be subject to military detention (though only until one of several disposition options, including civilian custody for criminal trial, is selected).  Section 1032 then goes on, in subpart (b), to state expressly that US citizens are exempt from this “mandatory detention” requirement (though lawful permanent residents are not). This obviously rules out the idea of a mandatory military detention for US citizens.  But note that it tends to rule in the idea that the baseline grant of detention authority in 1031 does in fact extend to citizens.  Otherwise there would be no need for an exclusion for citizens in section 1032, since the 1032 category is a subset of the larger 1031 category. So how does this compare to the status quo?  Well, here we should probably distinguish between captures inside the US and captures abroad. Only the former, in my view, was still an open question (vis-a-vis the relevance of citizenship) under the AUMF.