By Paul Reynolds
World affairs correspondent, BBC News website
Finally, there is the prospect that the Guantanamo Bay camp will close.
The prison camp at Guantanamo Bay has been controversial since it opened
President-elect Barack Obama's transition team has begun the debate about how this might be done - while stressing that no decisions have yet been taken.
In broad terms, the idea seems to be to abandon the military tribunals authorised under the Military Commissions Act 2006. These have begun to get under way at Guantanamo Bay. A trial procedure would be set up within the United States instead.
At the same time, a renewed effort would be made to find countries willing to take those prisoners already cleared for release.
The first is a legal problem and the second a practical one.
The legal problems involved in trying terrorist suspects have not yet been resolved. Some say that the prisoners should simply be brought before normal US courts. It is thought there are about 50 or so prisoners who might face trial, out of the 255 or so in the camp.
A new system would also come under the close scrutiny of the US courts and a case against it would probably go right up to the Supreme Court to test its constitutionality
The problem is that evidence against them might have been obtained either through coercion, or even torture, or from foreign agencies which have used similar methods.
Some of this evidence might be admitted in a trial before a military tribunal. So might hearsay evidence, in which someone relates what he or she was told, if the military judge decides that it would have "probative value to a reasonable person".
But neither would be acceptable under the normal rules of US courts.
Khalid Sheikh Mohammed, for example, charged at Guantanamo with responsibility for the 9/11 attacks, was subject to waterboarding.
It is true that he has expressed a wish to die but a civilian court in the US might not admit evidence against him gathered at Guantanamo Bay. Then what happens? It is hard to see him simply being released.
There is also the problem of whether the source of some evidence should be withheld from the prisoner.
So the idea being floated by one of Barack Obama's legal advisers, Laurence Tribe, a professor of law at Harvard University, is to explore the possibility of using a mixture of both civilian courts and courts martial.
Guantanamo Bay: search is now on for alternatives
"It would have to be some sort of hybrid legal system, rather than kangaroo courts," he said.
"I think the answer is going to be, they can be as securely guarded on US soil as anywhere else. We can't put people in a dungeon forever without processing whether they deserve to be there."
If the hybrid system under consideration did not distance itself from the military tribunals, it would attract criticism that Guantanamo Bay had simply been transposed to the United States.
A new system would also come under the close scrutiny of the US courts and a case against it would probably go right up to the Supreme Court to test its constitutionality.
There is likely to be political and legal opposition to the establishment of any new system for such a few cases.
Meanwhile, the question remains about what to do with the prisoners whose release has been approved. There is also a further group who are in limbo, with not enough presentable evidence against them nor confidence that they would not take up violence.
Despite considerable efforts, the US has not been able to persuade the home countries of the cleared suspects to have them back.
Often, of course, the prisoners oppose their home governments as much as they do that of the US and are seen a domestic danger.
Five human rights groups have now proposed that those prisoners whose home countries have refused to take them back should be taken in by European governments or the US itself.
Amnesty International's Daniel Gorevan said: "President-elect Obama has said that he will close [Guantanamo Bay]. Other governments can help make this happen by offering protection to individuals who cannot be released to their own countries."
Amnesty said that about 50 of the detainees currently held cannot lawfully be sent back to their countries of origin because "they would face a real risk of human rights violations such as torture or other ill-treatment". They come from countries including China, Libya, Russia, Tunisia, and Uzbekistan.
"Give us back America"
The American Civil Liberties Union called for Barack Obama to announce the closure of Guantanamo Bay on the first day of his presidency.
In a full page advertisement in The New York Times, it said: "Give us back the America we believe in."
However, the White House, which took years to evolve the current policy after constant legal challenges, has been more sceptical, suggesting that closure was easier said than done.
Spokeswoman Dana Perino said: "We've tried very hard to explain to people how complicated it is. When you pick up people off the battlefield that have a terrorist background, it's not just so easy to let them go.
"These issues are complicated, and we have put forward a process that we think would work in order to put them on trial through military tribunals."