Enemy combatants do not have a right to a speedy trial and do not have the same rights as criminal defendants, but Senator Graham is incorrect in asserting that they may be held without trial "for as long as the government deems necessary." Instead, they may only be held so long as the "enemy" with whom the detainee is affiliated is still an "enemy" in the context of a Congressionally authorized use of military force.
Detention of an enemy combatant is a close cousin of detention of a prisoner of war. It is a basis for detention based upon the detainee's status, for which the military only has to justify the military detention by showing that the detainee is a combatant member of a group which is an "enemy", such as a soldier, covert operative, or terrorist for that group.
The term "enemy" is a term of art which means a country or non-military armed group with which Congress has declared war, or has authorized the use of military force against.
For example, since the U.S. does not have Congressionally declared wars or authorizations for use of military force in place at this time against Russia and China, members of the militaries of Russia and China are not "enemy combatants" even though a large share of the U.S. military budget is devoted to preparing for war with these countries.
Detention of enemy combatants is authorized to continue until the U.S. is no longer at war with, or no longer authorizes the use of military force against, the combatant force that the detainee is a part of (i.e. "for the duration"). This has happened in a recent case where the U.S. made a peace treaty with a particular group connected with the Afghan War discussed below.
If the Authorization For Use of Military Force (2001) were repealed and not replaced by Congress today, all enemy combatant detainees in the U.S. would have a legal right to be released except the five that are currently facing separate quasi-criminal charges for specific wrongful conduct before a military commission, discussed below, rather than merely being combatants affiliated with a U.S. military enemy.
The main due process protection is the right to bring a habeas corpus petition challenging your classification as an enemy combatant.
In addition, the military evaluates whether the detention of an enemy combatant is lawful because the person is an enemy combatant, and whether this detention continues to be lawful in a Combatant Status Review Tribunal, rather than in a quasi-criminal court-like military commission.
Since it is not a criminal offense/charge (instead, it is a military tactic), it is not subject to the speedy trial act requirement.
As the Lawfare blog explains:
On Oct. 19, Judge Amit Mehta of the U.S. District Court for the
District of Columbia did something we have not seen in many a year: He
granted a Guantanamo detainee’s petition for a writ of habeas corpus,
ordering the man’s release.
The man in question is Asadullah Haroon Gul (aka Haroon al-Afghani),
an Afghan citizen who was captured alongside six other men in an
operation by Afghan government forces in early 2007. All the men, it
appears, were members of the armed group known as Hezb-e-Islami
Gulbuddin (HIG) commanded by former Afghan Prime Minister Gulbuddin
Hekmatyar. Though not formally part of the Taliban, Hekmatyar’s
political movement and its armed expression, HIG, were aligned
theologically and politically with the Taliban. And after the fall of
the Taliban, HIG became one of the armed groups fighting against the
new Afghan government, U.S. forces and other allied forces. In short,
HIG for many years was a paradigm example of an “associated force”
engaged in hostilities against the United States in connection with
the larger conflict with al-Qaeda and the Taliban. Indeed, in 2011, a
U.S. Court of Appeals for the D.C. Circuit opinion authored by
now-Attorney General Merrick Garland expressly affirmed as much in
Khan v. Obama.
But here’s the thing about military detention authority: The scope of
that authority will grow or shrink in accordance with the scope of the
underlying armed conflict on which the claim of military detention
authority is based. And thus it mattered a great deal when, in fall
2016, the then-government of Afghanistan reached a peace agreement
with HIG. Thus, even without the eventual U.S. decision to withdraw
from Afghanistan and end the fight against the Taliban too, the legal
foundation for military detention in cases predicated solely on
membership in HIG appeared to be going or already gone by late 2016. .
. .
In 2018, the Justice Department responded by abandoning its claim of
authority to detain based on HIG membership alone. It argued that Gul
still could be held, however, based on the distinct claim that Gul
separately had been involved with al-Qaeda itself.
Gul denies that argument on factual grounds, and for a time that was
the central issue in the case.
Then, with the recent full withdrawal of the United States from
Afghanistan, Gul appears to have expanded his argument to include a
much broader claim about the expiration of the legal grounds for
detention. That claim, if accepted by the court, could have sweeping
implications for other Guantanamo detainees.
Courts have generally declined to enforce speedy trial protections for people detained as enemy combatants who are then transferred to civilian criminal courts such as Ahmed Khalfan Ghailani (who initially faced military commission charges discussed below) and Jose Padilla, the only U.S. citizen detained in the United States for conduct in the United States as an enemy combatant.
Padilla was subsequently transferred from military custody to civilian federal criminal justice system pre-trial detention and tried and convicted there of a federal crime, while he was appealing his detention as an enemy combatant to the U.S. Supreme Court. This made the case moot, but left the U.S. Circuit Court of Appeals precedents made earlier in his case, which had upheld his detention as an enemy combatant in these circumstances, on the books as a binding precedent that the U.S. government could invoke in a future case.
The leading modern case on the topic is Hamdi v. Rumsfield, 542 U.S. 507 (2004) which addresses the authority to detain an enemy combatant, and the scope of the habeas corpus remedy in the case of a U.S. citizen who is alleged to be an enemy combatant. The official syllabus summarizes the case as follows:
After Congress passed a resolution–the Authorization for Use of
Military Force (AUMF)–empowering the President to “use all necessary
and appropriate force” against “nations, organizations, or persons”
that he determines “planned, authorized, committed, or aided” in the
September 11, 2001, al Qaeda terrorist attacks, the President ordered
the Armed Forces to Afghanistan to subdue al Qaeda and quell the
supporting Taliban regime.
Petitioner Hamdi, an American citizen whom the Government has
classified as an “enemy combatant” for allegedly taking up arms with
the Taliban during the conflict, was captured in Afghanistan and
presently is detained at a naval brig in Charleston, S. C. Hamdi’s
father filed this habeas petition on his behalf under 28 U.S.C. § 2241
alleging, among other things, that the Government holds his son in
violation of the Fifth and Fourteenth Amendments. Although the
petition did not elaborate on the factual circumstances of Hamdi’s
capture and detention, his father has asserted in other documents in
the record that Hamdi went to Afghanistan to do “relief work” less
than two months before September 11 and could not have received
military training.
The Government attached to its response to the petition a declaration
from Michael Mobbs (Mobbs Declaration), a Defense Department official.
The Mobbs Declaration alleges various details regarding Hamdi’s trip
to Afghanistan, his affiliation there with a Taliban unit during a
time when the Taliban was battling U. S allies, and his subsequent
surrender of an assault rifle.
The District Court found that the Mobbs Declaration, standing alone,
did not support Hamdi’s detention and ordered the Government to turn
over numerous materials for in camera review.
The Fourth Circuit reversed, stressing that, because it was undisputed
that Hamdi was captured in an active combat zone, no factual inquiry
or evidentiary hearing allowing Hamdi to be heard or to rebut the
Government’s assertions was necessary or proper.
Concluding that the factual averments in the Mobbs Declaration, if
accurate, provided a sufficient basis upon which to conclude that the
President had constitutionally detained Hamdi, the court ordered the
habeas petition dismissed. The appeals court held that, assuming that
express congressional authorization of the detention was required by
18 U.S.C. § 4001(a)–which provides that “[n]o citizen shall be
imprisoned or otherwise detained by the United States except pursuant
to an Act of Congress”– the AUMF’s “necessary and appropriate force”
language provided the authorization for Hamdi’s detention. It also
concluded that Hamdi is entitled only to a limited judicial inquiry
into his detention’s legality under the war powers of the political
branches, and not to a searching review of the factual determinations
underlying his seizure.
Held: The judgment is vacated, and the case is remanded.
Justice O’Connor, joined by The Chief Justice, Justice Kennedy, and
Justice Breyer, concluded that although Congress authorized the
detention of combatants in the narrow circumstances alleged in this
case, due process demands that a citizen held in the United States as
an enemy combatant be given a meaningful opportunity to contest the
factual basis for that detention before a neutral decision-maker.
Justice Souter, joined by Justice Ginsburg, concluded that Hamdi’s
detention is unauthorized, but joined with the plurality to conclude
that on remand Hamdi should have a meaningful opportunity to offer
evidence that he is not an enemy combatant.
Military Commissions Compared
A Military Commission trial is different from detention as an enemy combatant.
On November 13, 2001, President Bush issued a Military Order governing
the “Detention, Treatment, and Trial of Certain Non-Citizens in the
War Against Terrorism.” The Military Order effectively established
the novel military commissions at Guantanamo Bay, which began in 2004
with charges against four Guantanamo detainees.
In 2006, the Supreme Court struck down the military commissions (in
Hamdan v. Rumsfeld), determining that the commissions violated both
the Uniform Code of Military Justice and the 1949 Geneva Conventions.
In response, and in order to permit the commissions to go forward,
Congress passed the 2006 Military Commissions Act (MCA). Congress
significantly amended the MCA in 2009. In 2019, exercising authority
granted to him under the MCA, the Secretary of Defense published an
updated Manual for Military Commissions, which sets forth the current
procedures that govern the commissions.
The enemy combatant detainees who face military commission trials are a small subset of the total number of detainees:
Of the 779 men detained at Guantanamo at some point since the prison opened on January 11, 2002, thirty two total have been charged in the
military commissions. Charges were dismissed in 12 of those cases, and stayed in another. The U.S. government has procured eight convictions
total, six of which were achieved through plea agreements with the
defendants. U.S. federal courts have overturned several of the eight convictions in whole or in part.
There are five cases are currently ongoing in the commissions—and
another two pending appeal—including United States v. Khalid Sheikh Mohammed, et al.—the prosecution of the detainees alleged to be most
responsible for the September 11, 2001 attacks. None of those five
cases has yet gone to trial.
Only one military commission case to date produced a conviction following a military commission trial, and that conviction was vacated on appeal in Hamdan v. United States (D.C. Cir. 2012).
Another military commission defendant had his case transferred to a civilian criminal court where he was convicted following a civilian criminal trial (Ahmed Khalfan Ghailani) where he was convicted and is currently serving a life sentence in a federal prison. He is the only person originally charged by a military commission who is still incarcerated by the U.S., and again, in that case, outside the military commission process.
Two of the six military commission guilty pleas were subsequently vacated in the cases of David Hicks, who was then deported to Australia, and Noor Muhammed, who was deported to Sudan.
Five military commission cases remain outstanding.
Footnote: Enemy Non-Combatants
The parallel case law for civilians who are not combatant is Korematsu v. United States, 323 US 214 (1944), which while deeply criticized, has never been overruled as applied to non-citizens.
This case held that the U.S. may detain a non-combatant civilian, even as U.S. citizen, who has ancestry from an "enemy" (with "enemy" defined in the same ways as in connection with "enemy combatant") in an interment camp for the duration of a military conflict with that "enemy."
In that particular case, the "enemy" was the Japanese Empire upon which Congress declared war after the December 7, 1941 bombing of Pearl Harbor, and the non-combatant civilians who were interred were ancestrally Japanese or families of people who were ancestrally Japanese.
While this precedent has never been formally overruled as as applied to non-citizens, it has received heavy criticism in legal scholarship and is no longer good law as applied to U.S. citizen who were merely born citizens of an "enemy" or shared the ethnicity of an "enemy".
The portion of the Korematsu holding that upheld this detention in the case of U.S. citizens was abrogated by a majority opinion of conservative justices in U.S. Supreme Court in the case of Trump v. Hawaii, 138 S.Ct. 2392, 2423 (2018), which stated (in a case upholding the legality of Trump's Muslim ban as modified from its original version):
Finally, the dissent invokes Korematsu v. United States, 323 U.S.
214, 65 S.Ct. 193, 89 L.Ed. 194 (1944). Whatever rhetorical advantage
the dissent may see in doing so, Korematsu has nothing to do with
this case. The forcible relocation of U.S. citizens to concentration
camps, solely and explicitly on the basis of race, is objectively
unlawful and outside the scope of Presidential authority. But it is
wholly inapt to liken that morally repugnant order to a facially
neutral policy denying certain foreign nationals the privilege of
admission. The entry suspension is an act that is well within
executive authority and could have been taken by any other
President—the only question is evaluating the actions of this
particular President in promulgating an otherwise valid Proclamation.
The dissent's reference to Korematsu, however, affords this Court
the opportunity to make express what is already obvious: Korematsu
was gravely wrong the day it was decided, has been overruled in the
court of history, and—to be clear—“has no place in law under the
Constitution.” 323 U.S., at 248, 65 S.Ct. 193 (Jackson, J.,
dissenting).
But, it might very well continue to be good law as applied to non-citizens in the U.S. who were nationals of an "enemy".