Today, as we pause to remember those who died in the terrorist attacks in the US on 11 September 2001, we should also remember that much work still needs to be done to address the fallout from the Bush administration's extraordinary response to the attacks.
In Guantánamo, 225 men remain imprisoned, ostensibly in connection with these attacks, or with the "war on terror" that followed, even though, in all but a few dozen cases, they have never been charged with any crime, and only one man (Ali Hamza al-Bahlul) has been tried and convicted.
Two outstanding problems remain with Guantánamo. The first concerns the few dozen prisoners accused of involvement with the 9/11 attacks or other acts of international terrorism. As a result of the Bush administration's cavalier approach to the law, and its senseless and illegal approach to the use of torture, these men are still held without a trial date in sight.
If the Bush administration had treated 9/11 as a criminal act, and had built a criminal case against these men rather than torturing them in a network of secret prisons, they would probably have been tried and sentenced by now. As it is, however, only Ahmed Khalfan Ghailani has been put forward for a trial in a federal court, and the government plans to pursue other cases using a revamped version of the military commissions introduced by President Bush, which are damaged beyond repair.
To bring justice to these men - and for justice to be seen to be done - President Obama needs to pursue these cases in federal courts, knowing that no jury will fail to convict them if the government can produce any genuine evidence. The relatives of those who lost their lives on 9/11 deserve nothing less.
For the other prisoners at Guantánamo, the situation is more complicated. In June 2008, the US supreme court ruled that they had constitutionally guaranteed habeas corpus rights. Since then, the district courts have granted 29 out of 36 habeas appeals, deriding the government for relying on dubious informers within Guantánamo, multiple levels of hearsay and weak "mosaics" of evidence, and dealing a mortal blow to the Bush administration's allegations that Guantánamo held "the worst of the worst".
These are unsurprising results, given that prisoners were never adequately screened (either on capture, or in the years since), and that many were sold to US forces for bounty payments averaging $5,000 a head.
The prisoners' situation is further complicated by the fact that an interagency Guantánamo Task Force, established to review their cases and decide on their future, is effectively competing with the courts, even though it operates in secret and has only led, so far, to the release of a handful of prisoners.
However, even in the courts, problems remain with the government's definition of the prisoners. The courts are obliged only to consider whether the government has demonstrated, "by a preponderance of the evidence", that the men were connected to al-Qaida and/or the Taliban. As a result, judges have ruled, in other cases, that marginal characters in the inter-Muslim civil war between the Taliban and the Northern Alliance (which morphed into a war against the US after 9/11) can continue to be held.
I believe that, after eight years, it is time to examine whether it is plausible to continue holding men in connection with a "war on terror" that - despite being renamed by Obama - still seems to be regarded as a conflict that may go on forever, even though the specific conflict in which these men were captured - the overthrow of the Taliban - ended in November 2004, when Hamid Karzai was elected as the Afghan president.
Beyond Guantánamo, other problems remain. Obama is clinging to claims that foreign prisoners rendered to the US prison at Bagram - seized in similar circumstances to those at Guantánamo who were subjected to "extraordinary rendition" - can continue to be held without access to lawyers. In addition, Afghan prisoners in Bagram, who should be held as prisoners of war, according to the Geneva Conventions, still seem to be regarded as assets for whom rights are secondary to their perceived intelligence value.
Hovering over all these problems are even darker issues - the fate of the hundreds of men held in secret CIA prisons or rendered to other countries, and the long road to accountability for those who implemented these policies - but as the most bleakly iconic symbol of the Bush administration's response to 9/11, Guantánamo remains the most obvious challenge to Obama's stated ambition to "regain America's moral stature in the world".
On the eighth anniversary of 9/11, however, justice is being delivered neither to those regarded as genuinely dangerous, nor to those whose significance has been exaggerated.