This morning, lawyers for Guantánamo detainee Mohamedou Ould Slahi–the international best-selling author of “Guantánamo Diary”–filed a new motion in the D.C. district court, seeking an order to show cause why Slahi has not yet been provided with a hearing before the Periodic Review Boards (PRBs) that were created by President Obama in 2011. As the motion argues, Executive Order 13,567 not only mandated the creation of the PRB process, but also that, “[f]or each detainee, an initial review shall commence as soon as possible but no later than 1 year from the date of this order,” which was signed on March 7, 2011. Even if one only begins counting from the date on which the Department of Defense finally began holding PRBs (November 20, 2013), it’s still been over 18 months without a PRB for Slahi–even though that process was intended to implement the Executive Order’s important concession that “continued law of war detention” is unwarranted when it is not “necessary to protect against a significant threat to the security of the United States.” In other words, under the Executive Order, even if the 2001 Authorization for the Use of Military Force could be argued to authorize an individual’s continuing military detention, the government ought not to detain that individual if, as Slahi’s lawyers argue is true for their client, they pose no continuing threat.

So long as Slahi is entitled to enforce the Executive Order through a habeas proceeding (and, as the motion explains quite forcefully, there’s strong case law from both the Supreme Court and the D.C. Circuit supporting such judicial enforcement of Executive Orders that create legal obligations), it’s hard to see what the government’s argument is on the merits for why it wasn’t obligated to at least begin Slahi’s PRB process long before now–or why it shouldn’t be ordered to proceed forthwith.

But lest the headline of this new filing be focused on the PRB process, it’s worth making one more observation about Slahi’s case: His is one of the six cases in which the D.C. Circuit overturned the district court’s grant of habeas relief (in addition to al-AdahiAlmerfediHatim Latif. and Uthman). But unlike the other five–where the Court of Appeals expressly reversed the district court and held the underlying detention to be lawful–the panel in Slahi’s case only vacated the district court’s decision, remanding the matter to the district court for further fact-finding. That decision came on November 5, 2010–and there has been no subsequent ruling from the district court on the underlying merits of Slahi’s claims.

Thus, whereas it’s easy to look at today’s filings on Slahi’s behalf as an effort to force the government to provide the PRB process to which Slahi is arguably entitled under the Executive Order (which would ask whether Slahi poses a continuing threat), it should also be understood as a reminder of the extent to which his underlying habeas petition (which asks whether he’s properly detained in the first place) continues to languish in litigation purgatory.