We have a short Note on this issue in the new edition of International Criminal Law casebook by Paust, Bassiouni.
There should at least be provision of medical treatment for detainees who make the choice to die so that their death does not involve needless suffering.
If the US chooses to intervene in such a decision, the US should not engage in torture or cruel, inhuman or degrading treatment because such are absolutely unlawful under the laws of war, human rights law, and the CAT. But the critical criterion with respect to “torture” seems to be the non-self-applicative word “severe.” It appears that one criterion accepted by international tribunals regarding cruel or inhuman treatment is the non-self-applicative word “serious.” Of course, one wants to look at the trends in decision for guidance with respect to particular tactics or treatment.
If they want to starve themselves to death, they should be allowed to do so. Is this not a Human Right that should never be abridged ? As the anti-gun and "pro-life crowds make clear, government is supposed to force people that don't want to live to do so and it is supposed to deny them the means of killing themselves. So, the one thing these guys can do is refuse to eat. And what is the response? To torture them with forced eeding via nasal tube. Water boarding would have probably been less traumatic.
