For the past 11 days, since President Bush announced that he would like the detention camp “to be empty”, we have been able to assume that we are seeing the last of Guantanamo, at least on its present scale.

Bush’s startling reversal shows the dim recognition of the US, at last, of the calamitous effect of Guantanamo on its reputation among its allies and its potential enemies.

But that has crystallised, it seems, only in response to the world’s disbelieving outrage at the three recent prisoner suicides and the breathtakingly dismissive comments of two US officials, which exposed beyond parody the US’s inability to see itself as others do.

The Supreme Court could effectively shut down Guantanamo by ruling against the special tribunals set up by Bush to try the tiny minority who have been charged, and even against the principle of indefinite detention for the rest.

But if it says nothing clear-cut, there must be a suspicion that the US would then merely shrink the camp from the present number of about 465 to the point — say 100 prisoners or so — where it would hope the world would forget. If the US intended to send every prisoner away soon, it surely would not be building Guantanamo’s Camp Six, a high-security prison for 200 inmates.

“We’re waiting on our Supreme Court to act,” Bush said on June 14, a sign that he is prepared to follow the court’s lead. This in itself was surprising: the issue before the court is whether to uphold the “wartime” powers that Bush gave himself after September 11, 2001 — above all, the creation of special military tribunals for the Guantanamo prisoners.

The court’s decision, in a case brought by Salim Ahmed Hamdan, Osama bin Laden’s driver, will affect most directly only the ten prisoners who have been charged so far and are waiting for tribunals to begin. Hamdan argues that the tribunals are illegitimate and that he should be tried by a federal court.

But the court may also choose to comment on the principle of indefinite detention without charge, which affects all of those at Guantanamo.

Whatever the court’s eight justices decide — Chief Justice John Roberts excused himself because he took part in the appeals court stage of the case — they will go a long way to define how far a president can extend his “wartime” authority when fighting an unconventional enemy.

There has been a temptation among the strongest supporters of the US to say that Guantanamo was justified by the unconventional nature of the War on Terror. That is to gloss over its twin offences: the inherently unfair nature of the tribunals, and the principle of indefinite detention without charge.

The tribunals allow “witnesses” to give evidence against prisoners in unsworn statements instead of testimony. The prisoners may not know the evidence against them, if it is deemed to be “classified”, which may simply mean that it is what a prisoner in the next block has said after four years of interrogation.

There is no appeal outside the military, and the courts may impose the death penalty (although the Administration has not sought it for any of the ten charged so far).

There is no justification for this. If the US has adequate evidence against these people, then it should try them in conventional courts, military or otherwise, or send them back to their home countries to be tried.

And if it does not? The US has the right, under international laws of war, to remove an enemy from the battlefield for the duration of the war. But in the case of the War on Terror, the war has no defined end. And if the US chooses to stick by that distorted designation, then its “detainees” become prisoners of war, and cannot, for example, be interrogated.

The passage of 4½ years has magnified the ugliness of these excuses to the point where even the closest allies of the US cannot overlook them. Tony Blair has called for the camp to close, and if Anders Fogh Rasmussen, the Danish Prime Minister, a strong supporter of the Iraq war, calls Guantanamo a violation of “the very principle of the rule of law” then the US must know it has a problem.