The prosecution by a military court last week of the Australian David Hicks had a surface veneer of respectability (Australian's guilty plea at Guantánamo hearing, March 27). But this was a facade. Yes, Hicks "is the first terror suspect to face prosecution in revised military tribunals established after the US Supreme Court last year found the Pentagon's system for trying such detainees was unconstitutional". But that's a dubious distinction.The Australian government has talked publicly about their satisfaction in getting "this Australian to the head of the queue" for a military commission, saying it shows the "degree of influence" enjoyed by John Howard's government in Washington.

Some achievement. Securing a trial wholly run by the US military that allows coerced evidence from secret detention centres and can impose the death penalty (including for "spying") with limited means of appeal, doesn't seem much of a tribute to diplomacy.

"Under a diplomatic deal, Mr Hicks would serve that term in Australia," the article reported; but this will provide scant hope for the 385 prisoners still held at the prison. It seems highly unlikely that the Pakistanis, Yemenis, Bosnians, Saudis, Afghans, Chinese and at least seven long-term UK residents still imprisoned will be able to strike such deals.

Hicks was the only prisoner ever allowed a family visit at Guantánamo and, to this extent, Australian influence did make some difference. The US authorities and some of their defenders have hailed the Hicks sentence as an example of the justice system at Guantánamo finally working. But, in truth, the whole process is a travesty of justice. Even Hicks's case was handled chaotically and deeply unfairly. After being labelled an "enemy combatant", spending more than five years in detention (including long periods of isolation where torture is alleged), Hicks's decision to go for a deal may have owed as much to desperation as anything else.

When Hicks apparently "told his lawyers he grew his hair to block the constant light in his cell", he will have had good grounds. He was reportedly held in two of Guantánamo's isolation blocks, Camp 5 and Camp 6, where the regime is one of extreme isolation and where fluorescent lighting burns in the cells 24 hours a day. Detainees in these units are not allowed to sleep without their hands and face showing.

As we show today in a new report (www.amnesty.org.uk/guantanamo), with the US authorities now holding 80% of Guantánamo's 385 detainees in harsh and inhumane solitary confinement conditions, despairing prisoners are now dangerously close to full-blown mental and physical breakdown. There were three apparent suicides at the camp last year, and there will almost certainly be others unless the US authorities stop warehousing prisoners in solitary and allow independent medical personnel to examine all the men.

Hicks was able to secure a deal with Guantánamo's kangaroo court. But for the rest, marooned at Guantánamo, it's either a shabby show trial or no trial at all. As "enemy combatants", the US says it can keep them indefinitely, or until the "war on terror" is concluded. It's time to end this farce.

Kate Allen is the UK director of Amnesty International: director@amnesty.org.uk

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