Defenders of the detention provisions in the defense funding bill currently under debate in Congress are arguing that they do not authorize the indefinite military detention of American citizens. They're saying the Supreme Court already did that.
"There is no bar to this nation's holding one of its own citizens as an enemy combatant," Sen. Carl Levin (D-Mich.) said during his floor speech defending the detention provisions Tuesday. "That's not me, that's not Sen. Graham, that's not Sen. McCain. That's the Supreme Court of the United States recently."
Levin was referring to 2004's Hamdi v. Rumsfeld case, in which the Supreme Court ruled that Yaser Esam Hamdi, a US national captured during the 2001 invasion of Afghanistan, could be held in military detention but not without habeas review.
That case, however, involved an actual battlefield in an actual war. The current version of the defense funding bill—formally known as the National Defense Authorization Act, or NDAA—goes further. It says the military can detain anyone deemed to be "a part of" or deemed to have "substantially supported" Al Qaeda, the Taliban, or "associated forces." Terror suspects would not have to be on an actual battlefield or fighting in an actual war, as Hamdi was, to be detained by the military. And although Americans, unlike foreigners, are not required to be held in military detention if apprehended on American soil, the NDAA affirms that they can be, based on the 2001 Authorization to Use Military Force (AUMF) against Al Qaeda. (Levin said in his floor speech that despite its threat to veto the bill, the administration had approved that language.)
Benjamin Wittes, a Brookings Institution scholar who thinks the government should have the option to put Americans in domestic military detention under some circumstances, described Hamdi's capture as "a very traditional battlefield-type capture where they guy happens to be US citizen. It's very different from yanking someone out of the criminal-justice system or picking someone up at O'Hare airport."
Crucially, the Hamdi case didn't actually settle the issue of whether or not a US citizen apprehended domestically by law enforcement could be put into military detention. It's happened before: Twice, individuals captured in the United States were detained by the military. In both cases, one involving a citizen and the other a legal resident, the detainees were ultimately shunted into the criminal system for fear that the Supreme Court would find military detention unconstitutional. Perhaps more significantly, both examples, Jose Padilla and Ali Saleh al-Marri, occurred years ago, and until Obama took office there was no effort by Congress to force the executive branch to use the military to detain people suspected of terrorism.
The shift toward using military detention authority means that Americans could someday be subject to the standards of proof crafted by Guantanamo Bay legal cases, standards that over the years have shifted substantially in the government's favor. Early on, detainees were winning many of their cases because the evidence the government was using to hold them was often based on intelligence reports judges found unreliable. So the courts simply shifted the standards so that judges would have to assume the government's evidence was true.