It is five years since US President Barack Obama first vowed to close the Guantanamo Bay prison camp in Cuba. Time is now running out for him to make good on that pledge.
A total of 166 prisoners are being held in the camp, at a US naval base, ostensibly under international laws that will expire at the "end of hostilities".
Some lawyers argue that that has already occurred; others say it certainly will be the case when American troops withdraw completely from Afghanistan next year.
While there appears to be no impediment to the release of the majority of these inmates, 50 of them have been classified as "too dangerous" to be set free.
Yet, as The National reported yesterday, the American military says these men can't be prosecuted, in some cases because doing so might reveal sensitive information.
A lawyer for one of those 50 prisoners says the allegations against her client are no more serious than those against men who have already been freed. But without a trial, the public cannot judge the validity of this claim.
When, in 2001, former US president George W Bush declared "war on terror" in the aftermath of the September 11 attacks, it was clear that the world was entering unchartered territory.
This war has given us a prison camp like no other at Guantanamo, and has given rise to the concept of "extraordinary rendition", where a suspect can be transferred from one country to another without legal extradition proceedings.
It has also seen the emergence of new weapons, including pilotless drone aircraft that have killed suspects, including American citizens, well beyond the field of engagement.
It is probable that many of the Guantanamo detainees were jailed for good reasons. But after so many years, some are no longer a threat. The problem remains with those deemed "too dangerous".
A trial would evaluate the accuracy of this determination and reveal better options than the penal version of suspended animation.
Mr Obama cannot simply ignore the problem and hope it goes away.