Of all the victims of the political dysfunction in Washington, of a Congress determined to thwart the White House at all costs, the 166 inmates of Guantánamo Bay are surely the most ill-treated. The reason they are still there, four years after Barack Obama first promised to close the prison, has little to do with problems over their release or transfer, although those still exist. They are there largely because Congress has cut off the funds to move those accused to detention in the US and imposed conditions which make transfer out of the US all the more difficult – a hurdle signed into law, it also has to be remembered, by Mr Obama earlier this year. This means that 86 of the 166 still detained, who have been approved for transfer out of US custody, have been stuck in this hellhole for the last two and a half years.

These decisions have human consequences. There is growing desperation among the camp's inmates, 100 of whom are now on hunger strike. As the Observer revealed in a recent interview, the British resident Shaker Aamer does not now think he will make it out of the prison alive. Britain has officially maintained that it is committed to extracting Mr Aamer. His lawyers fear that darker motives are at work, as Mr Aamer is alone in having been cleared for release to one country – Saudi Arabia, where he faces an unsafe trial and long imprisonment. Britain might be less than keen on seeking Mr Aamer's return, as he alleges that a UK intelligence agent was present while he was being beaten. His case exemplifies the huge ambivalence which all of America's allies still share in closing this chapter in the dirty war on terror. The only damage that a free Mr Aamer can cause is reputational. He is already suing MI5 and MI6 for defamation.

In the process, public confidence in all these institutions continues to suffer. Even though his own standing has taken several knocks as a result of bending in the political wind, Mr Obama was right yesterday to say that he will try, again, to close the prison. Guantánamo still stains every country that colludes in its continued existence, including the UK and its security services. Indeed it weakens co-operation with allies. And it still serves as a recruitment tool for extremists. A country that fails to try those accused of planning or committing terrorists acts in its civilian courts is a society that admits defeat. A country that detains people without charge because it knows that any charges would be thrown out of a proper court is no different, in its behaviour to these inmates, from dictatorships which scorn the rule of law.

It has taken a mass hunger strike and the arrival of 40 navy nurses to bring this issue to a head. The situation inside the prison is unsustainable, and it is long past time for all of America's politicians to admit it.