It is often claimed in raising objections to the use of military commissions to try the prisoners at Guantanamo that these prisoners must be tried under the protection of the Sixth Amendment of the United States Constitution and perhaps according to the exact standards laid out in the Uniform Code of Military Justice for any such trials to be fair. The problem with this seemingly reasonable and humane position is that it is highly probable that neither the Sixth Amendment nor the Uniform Code of Military Justice applies to the great majority of foreign detainees held at Guantanamo.
The Sixth Amendment, while a bedrock ideal of American justice, pertains to those being tried under the US Justice system for acts committed on American soil, not extraterritorial acts:
http://bulk.resource.org/...
Therefore, an attack on a US Embassy or the WTC might fit the criteria for federal trials with 6th Amendment protection. Plotting attacks on American expeditionary forces during combat operations in foreign territory would probably not.
As for the Uniform Code of Justice, which is also sometimes suggested as a pre-existing structure for the Guantanamo prisoners to be tried under, that is for US service personnel not foreign soldiers, civilians or belligerents captured in combat.
So to determine what sort of legal process they should face (if at all), the definition of these prisoners' status must first be determined solely in accordance with the Geneva Conventions. This return to a proper reliance on the Geneva Conventions, too long abandoned by Bush 43, to define what rights these prisoners do or do not have under the laws of war codified therein will in turn lead to our renewed compliance with commonly accepted international standards for the treatment of detainees. This return to the norms of international justice will furthermore confer manifold benefits to our status within the community of nations.
Therefore, it must be decided, if it has not already been and even then perhaps it should be revisited for the sake of fairness, whether the prisoners fall into the category of POWs, civilians or terrorists/non-state belligerents, who are not generally covered by the Geneva Convention as a rule (although this determination is quite complex--see Jennifer Elsea's CRS Report for Congress "Terrorism and the Law of War: Trying Terrorists as War Criminals").
Military commissions, despite all their negative connotations due to their abuse as one-size-fits-all tribunals by Bush 43, are reasonable clearinghouses for these sorts of evidentiary procedures, with any further potential legal proceedings to be determined after said commissions make a finding, much as a grand jury operates in civil law.
Keep in mind that absent some sort of war crime, POWs are not supposed to be tried at all, only held for the duration of a declared conflict and then released to their native country (or a neutral one in the case of imminent danger to the prisoner to be released), so long as military authorities determine they are not a risk to return to the battlefield. The converse is also true, of course: that is, a POW may be held as long as deemed reasonable by military authorities and without access to legal appeal in most cases by cause of taking up arms against the United States during an active military conflict.
If there are alleged war criminals among these individuals after the determinations of detainee category are made, they should be tried according to the principals of the Nuremberg trials, the gold standard for war crimes prosecution.
However, continually insisting that these foreign prisoners, some of whom may have been captured during active combat against US military forces, are entitled to every legal benefit that would protect an accused American citizen or member of the US military is fallacious and not borne out by past precedents of American justice for captured enemy belligerents and soldiers. In fact, the legal rights that these prisoners are entitled to accrue not from American jurisprudence but from the internationally agreed upon rules of warfare contained in the Geneva Conventions. That is the sole standard that must guide our actions in determining their fate.