The Guardian view on Guantánamo Bay: betraying the victims of terrorism too | Editorial

There is no neat exit point from grief. Each anniversary, each life event, each addition to or loss from the family, can bring renewed pain to the bereaved. For relatives of the almost 3,000 killed in the terror attacks on September 11, 2001, that suffering has been compounded by the lack of accountability for their deaths.

This week, the US announced that it had reached a plea deal with Khalid Sheikh Mohammed, described as the attack's architect, and two accomplices, Walid Muhammad Salih Mubarak Bin 'Attash, and Mustafa Ahmed Adam al-Hawsawi. They will avoid the death penalty, instead receiving life sentences in exchange for pleading guilty to all the offences with which they were charged. Negotiations continue with two more men. All have been in US custody since 2002, and are held at Guantánamo Bay, in Cuba. For many relatives, there is anger that there will be no trial, and in some cases that the men will not be executed. But for others there is some relief that after 23 years there is a kind of conclusion to the case, however partial and unsatisfactory.

Last year, Fionnuala Ni Aoláin, the first UN rights investigator to be allowed to visit since the camp's establishment, described its use of torture as "a betrayal of the rights of victims" of terrorism, as well as breaching the rights of those who had spent more than two decades in indefinite detention. Torture was not merely the standard operating procedure at Guantánamo Bay. It was its raison d'etre. Men were taken there because it lay outside the rule of law. The abuse, however, made it essentially impossible to proceed with material derived from their interrogations, even under the conditions of a military tribunal rather than a criminal trial. Victims of torture lie so that it will stop. This week's plea deals are not a vindication of the site's existence: quite the opposite. Over a decade of pretrial hearings have been absorbed by litigating torture, rather than establishing responsibility for terrorism.

While conditions have improved, Prof Ni Aoláin, then the special rapporteur on human rights and counter-terrorism, wrote that detainees were still subject to "cruel, inhuman and degrading treatment", in addition to living with the "unrelenting harms" from previous abuses. Several have killed themselves; others have been left with severe mental illness.

Guantánamo Bay should never have been opened. This was the conclusion not only of human rights groups and lawyers, but of the US general tasked with setting up the detention camp, Michael Lehnert. Even without considering the moral and legal case, he - like others - quickly concluded that many detainees had little intelligence value, and insufficient evidence linking them to war crimes. Of the hundreds kept there, only 18 have been charged with a crime. In 2009, Barack Obama, then US president, vowed to shut the facility within a year. But despite releases and transfers, around 30 men are still held, at a cost of around $14m each annually.

The conclusion of a legal process - however inadequate - means that for some, the detention camp will become more akin to a prison. But as Maj Gen Lehnert wrote almost a decade ago, it is hard to overstate the damage caused by its continuing existence. Repressive governments use it to deflect attacks on their own policies; violent extremists employ it as a recruiting tool. As long as it remains open, the place "where due process goes to die" will remain a stain upon the US.