Background

The Attorney General announced on June 10, 2002, that an American citizen, Jose Padilla,also known as Abdullah Muhajir, was arrested May 8, 2002 upon his return from Pakistan, allegedlywith the intent of participating in a plot to use a radiological bomb against unknown targets withinthe United States. Padilla was detained under a court order as a material witness until theDepartment of Justice faced a court deadline to either bring charges or release him. Afterprosecutors reportedly either lacked the physical evidence or were unwilling to disclose classifiedevidence necessary to bring charges against Padilla, President Bush signed an unspecified orderdeclaring him to be an "enemy combatant," and transferred him to the custody of the Department ofDefense. (9) TheAdministration takes the position that the law of war allows the United States to detain indefinitelymembers, agents or associates of Al Qaeda and other terrorist organizations, without charging themwith a crime under either criminal statutes or the international law of war, notwithstanding theirAmerican citizenship. (10) The Administration also initially denied Padilla access to his attorney, (11) arguing that he has noconstitutional right to an attorney because he has not been charged with a crime. (12) After a federal judge ruledthat Padilla has a right to challenge his detention and the concomitant right to consult with anattorney, (13) the government moved for a reconsideration of the order based on its assertion that no conditions werepossible that would permit Padilla to communicate with his lawyer without endangering nationalsecurity, which the judge considered but rejected. (14) The judge certified the case for interlocutory appeal to the U.S.Court of Appeals for the Second Circuit, including the issue of the President's authority to orderPadilla's detention as an enemy combatant. (15) The Second Circuit held that the President does not have theinherent authority, nor has Congress authorized him to declare U.S. citizens captured on U.S.territory in non-combat circumstances to be enemy combatants and place them under militaryjurisdiction. (16) Thegovernment granted Padilla a limited right to meet with his attorney under government monitoringand appealed the decision to the Supreme Court, which heard the case on expedited appeal. TheCourt disposed of the case without deciding the merits, in a 5-4 order vacating the decision belowand holding that the petition should have been brought in the Fourth Circuit, where Padilla is beingheld, rather than New York. 
The Supreme Court decided the petition of another American citizen who was detainedwithout charges as an "enemy combatant" on the same day. (17) Yaser Eser Hamdi, whohad been captured in Afghanistan, was initially detained at the U.S. Naval Station in GuantÃ¡namoBay, Cuba with other detainees captured in Afghanistan and other countries, until it was discoveredthat he was born in Baton Rouge and thus had a colorable claim to U.S. citizenship. He was thentransferred to a high-security naval brig in South Carolina, where he was held in military custodywithout criminal charge. After an attorney filed a petition for habeas corpus on his behalf, thegovernment asserted it had the unreviewable prerogative to detain him without trial and withoutproviding him access to an attorney, as a necessary exercise of the President's authority asCommander-in-Chief to provide for national security and defense. (18) The Fourth Circuit largelyagreed with the government's position, reversing two orders issued by the district court and orderingthe case dismissed. (19) The Supreme Court reversed in part, affirming the President's authority to detain Hamdi as an"enemy combatant" under the AUMF, but ruling that Hamdi was entitled to a hearing to challengehis status. (20) Thegovernment subsequently negotiated an agreement that would allow Hamdi to return to SaudiArabia, obviating the need for a hearing and a determination of whether Hamdi was entitled to theassistance of counsel. The government interprets the decision in Hamdi to apply to Padilla as wellas the detainees at GuantÃ¡namo Bay.
These two cases are distinguishable because the government reportedly captured Hamdi onthe battlefield, possibly creating a presumption that he is a combatant. (21) Unlike Padilla, Hamdi wasnot alleged to have committed specific acts which could violate the law of war if committed by alawful soldier. Padilla, even if he were a legitimate enemy combatant, would not likely be entitledto combat immunity for his alleged involvement in an enemy plot to commit acts of terrorism onAmerican soil. (22) Inboth cases, the Government invoked its authority under the international law of war, and thePresident's authority as Commander-In-Chief, to justify the detention. (23) The Administration alsoargued that if congressional authorization were necessary, it could be found in the Authorization toUse Force ("AUMF") (24) and other statutes. The Supreme Court agreed that the AUMF authorizes the detention ofcombatants captured during hostilities, but did not elaborate on the scope of that authority, nor didit decide whether the President has inherent authority to order detentions or if other statutoryauthority also applied.

	Status and Detention of Persons in War

The law of war divides persons in the midst of an armed conflict into two broad categories:combatants and civilians. (25) This fundamental distinction determines the international legalstatus of persons participating in or affected by combat, and determines the legal protections affordedto such persons as well as the legal consequences of their conduct. (26) Combatants are thosepersons who are authorized by international law to fight in accordance with the law of war on behalfof a party to the conflict. (27) Civilians are not authorized to fight, but are protected fromdeliberate targeting by combatants as long as they do not take up arms. In order to protect civilians,the law of war requires combatants to conduct military operations in a manner designed to minimizecivilian casualties and to limit the amount of damage and suffering to that which can be justified bymilitary necessity. To limit exposure of civilians to military attacks, combatants are required, as ageneral rule, to distinguish themselves from civilians. Combatants who fail to distinguishthemselves from civilians run the risk of being denied the privilege to be treated as prisoners of warif captured by the enemy.
The treatment of all persons who fall into the hands of the enemy during an internationalarmed conflict depends upon the status of the person as determined under the four GenevaConventions of 1949. Under these conventions, parties to an armed conflict have the right to captureand intern enemy soldiers (28) as well as civilians who pose a danger to the security of thestate, (29) at least for theduration of hostilities. (30) The right to detain enemy combatants is not based on the supposition that the prisoner is "guilty" asan enemy for any crimes against the Detaining Power, either as an individual or as an agent of theopposing state. POWs are detained for security purposes, to remove those soldiers as a threat fromthe battlefield. The law of war encourages capture and detention of enemy combatants as a morehumane alternative to accomplish the same purpose than by wounding or killing them. 
Enemy civilians may be interned for similar reasons, although the law of war does not permitthem to be treated as lawful military targets. As citizens of an enemy country, they may be presumedto owe allegiance to the enemy. The law of war traditionally allowed for their internment and theconfiscation of their property, not because they are suspected of having committed a crime or evenof harboring ill will toward the host or occupying power; but rather, they are held in order to preventtheir acting on behalf of the enemy and to deprive the enemy of resources it might use in its warefforts. Congress has delegated to the President the authority, during a declared war or byproclamation, to provide for the restriction, internment or removal of enemy aliens deemeddangerous. (31) TheSupreme Court has upheld internment programs promulgated under the Alien Enemy Act. (32) This form of detention,like the detention of POWs, is administrative rather than punitive, and thus no criminal trial isrequired. (33) 
The Detaining Power may punish enemy soldiers and civilians for crimes committed priorto their capture as well as during captivity, but only after a fair trial in accordance with the relevantconvention and other applicable international law. However, it is unclear whether a person who isneither a POW nor an enemy alien may be detained without criminal charges, (34) and if such detention islawful, what process is due the detainee under the Constitution or international law. The conditionsof detention may also give rise to the question of whether they amount to punishment, in this case,notwithstanding DoD's recognition that the purpose for detaining "enemy combatants" is not punitivein nature. (35) 

	U.S. Precedent for Detention of Citizens as Enemy Combatants

The Department of Justice reads the Hamdi decision as supporting its reliance primarily ontwo cases to support its contention that the Constitution permits the detention without criminalcharge of American citizens under certain circumstances. The government argues that the 1942Supreme Court decision in Ex parte Quirin (the German saboteurs case) and the 9th Circuit case Inre Territo , read together, permit the government to hold American citizens as "enemy combatants,"regardless of their membership in any legitimate military organization. Others, however, distinguishthose cases as dealing with occurrences during a war declared by Congress and involving membersof the armed forces of hostile enemy states, and further argue that the Civil War case Ex parteMilligan forecloses this theory. 

		Ex Parte Quirin

After eight Nazi saboteurs were caught by the Federal Bureau of Investigation (FBI), thePresident issued a proclamation declaring that "the safety of the United States demands that allenemies who have entered upon the territory of the United States as part of an invasion or predatoryincursion, or who have entered in order to commit sabotage, espionage or other hostile or warlikeacts, should be promptly tried in accordance with the law of war." (36) The eight Germansaboteurs (one of whom claimed U.S. citizenship) were tried by military commission for enteringthe United States by submarine, shedding their military uniforms, and conspiring to use explosiveson certain war industries and war utilities. In the case of Ex parte Quirin , the Supreme Court deniedtheir writs of habeas corpus (although upholding their right to petition for the writ, despite languagein the Presidential proclamation purporting to bar judicial review), holding that trial by such acommission did not offend the Constitution and was authorized by statute. (37) It also found thecitizenship of the saboteurs irrelevant to the determination of whether the saboteurs were "enemybelligerents" within the meaning of the Hague Convention and the law of war. (38) 
To reach its decision, the Court applied the international common law of war, as Congresshad incorporated it by reference through Article 15 of the Articles of War, (39) and the President'sproclamation that 
[A]ll persons who are subjects, citizens or residents ofany nation at war with the United States or who give obedience to or act under the direction of anysuch nation, and who during time of war enter or attempt to enter the United States ... through coastalor boundary defenses, and are charged with committing or attempting or preparing to commitsabotage, espionage, hostile or warlike acts, or violations of the law of war, shall be subject to thelaw of war and to the jurisdiction of military tribunals. (40) 
Whether the accused could have been detained as "enemy combatants" without any intent totry them before a military tribunal was not a question before the Court, (41) but the Court suggestedthe possibility. It stated: 
By universal agreement and practice, the law of wardraws a distinction between the armed forces and the peaceful populations of belligerent nations andalso between those who are lawful and unlawful combatants. Lawful combatants are subject tocapture and detention as prisoners of war by opposing military forces. Unlawful combatants arelikewise subject to capture and detention , but in addition they are subject to trial and punishment bymilitary tribunals for acts which render their belligerency unlawful. (42)
In its discussion of the status of "unlawful combatant," the Court did not distinguish betweenenemy soldiers who forfeit the right to be treated as prisoners of war by failing to distinguishthemselves as belligerents, as the petitioners had done, and civilians who commit hostile acts duringwar without having the right to participate in combat. Both types of individuals may be called"unlawful combatants," yet the circumstances that give rise to their status differ in ways that may belegally significant. (43) However, the Court did recognize that the petitioners fit into the first category, (44) and expressly limited itsopinion to the facts of the case:
We have no occasion now to define with meticulouscare the ultimate boundaries of the jurisdiction of military tribunals to try persons according to thelaw of war. It is enough that petitioners here, upon the conceded facts, were plainly within thoseboundaries, and were held in good faith for trial by military commission, charged with being enemieswho, with the purpose of destroying war materials and utilities, entered or after entry remained inour territory without uniform -- an offense against the law of war. We hold only that those particularacts constitute an offense against the law of war which the Constitution authorizes to be tried bymilitary commission. (45) 

		In Re Territo

In the case In re Territo , (46) an American citizen who had been inducted into the Italian armywas captured during battle in Italy and transferred to a detention center for prisoners of war in theUnited States. He petitioned for a writ of habeas corpus , arguing that his U.S. citizenship foreclosedhis being held as a POW. The court disagreed, finding that citizenship does not necessarily "affect[]the status of one captured on the field of battle." (47) The court stated:
Those who have written texts upon the subject ofprisoners of war agree that all persons who are active in opposing an army in war may be capturedand except for spies and other non-uniformed plotters and actors for the enemy are prisoners of war. (48)
The petitioner argued that the Geneva Convention did not apply in cases such as his. Thecourt found no authority in support of that contention, noting that "[i]n war, all residents of theenemy country are enemies." (49) The court also cited approvingly the following passage:
A neutral, or a citizen of the United States, domiciledin the enemy country, not only in respect to his property but also as to his capacity to sue, is deemedas much an alien enemy as a person actually born under the allegiance and residing within thedominions of the hostile nation. (50) 
While recognizing that Quirin was not directly in point, it found the discussion of U.S. citizenshipto be "indicative of the proper conclusion":
Citizens who associate themselves with the military armof the enemy government, and with its aid, guidance and direction enter this country bent on hostileacts are enemy belligerents within the meaning of the Hague Convention and the law of war. (51)
The court had no occasion to consider whether a citizen who becomes associated with anarmed group not affiliated with an enemy government and not otherwise covered under the termsof the Hague Convention could be detained without charge pursuant to the law of war, (52) particularly those notcaptured by the military during battle. 
Confining the Territo and Quirin opinions to their facts, they may not provide a solid foundation for the President's designation and detention of Padilla as an enemy combatant. It maybe argued that the language referring to the capture and detention of unlawful combatants --seemingly without indictment on criminal charges -- is dicta ; the petitioners in those cases did notchallenge the contention that they served in the armed forces of an enemy state with which theUnited States was engaged in a declared war. We are unaware of any U.S. precedent confirming theconstitutional power of the President to detain indefinitely a person accused of being an unlawfulcombatant due to mere membership in or association with a group that does not qualify as alegitimate belligerent, with or without the authorization of Congress. (53) The Supreme Courtrejected a similar contention in the Civil War case of Ex parte Milligan , discussed infra , whereCongress had limited the authority to detain persons in military custody.
At most, arguably, the two cases above may be read to demonstrate that, at least in thecontext of a declared war against a recognized state, U.S. citizenship is not constitutionally relevantto the treatment of members of enemy forces under the law of war. Neither case addresses theconstitutionality of the process used to determine who is a member of an enemy force and whethera detainee qualifies for POW privileges. Inasmuch as the President has determined that Al Qaedais not a state but a criminal organization to which the Geneva Convention does not apply, (54) and inasmuch as the HagueConvention would seem to apply to neither Al Qaeda nor the Taliban for the same reasons that havebeen given to preclude their treatment as prisoners of war, (55) it may be argued that AlQaeda is not directly subject to the law of war and therefore its members may not be detained as"enemy combatants" pursuant to it solely on the basis of their association with Al Qaeda. (56) Taliban fighters capturedin Afghanistan are a closer fit within the traditional understanding of who may be treated as enemycombatants, but may be able to contest the determination that they are not entitled to POWstatus. (57) 

		Ex Parte Milligan

In Ex parte Milligan, (58) the Supreme Court addressed the question whether a civiliancitizen of Indiana who was allegedly a member of the Sons of Liberty, an organized group ofconspirators with alleged links to the Confederate States that planned to commit acts of sabotageagainst the North, could constitutionally be tried by military commission. The Court recognizedmilitary commission jurisdiction over violations of the "laws and usages of war," but stated thoselaws and usages "... can never be applied to citizens in states which have upheld the authority of thegovernment, and where the courts are open and their process unobstructed." (59) The Supreme Courtexplained its reasoning:
It will be borne in mind that this is not a question of thepower to proclaim martial law, when war exists in a community and the courts and civil authoritiesare overthrown. Nor is it a question what rule a military commander, at the head of his army, canimpose on states in rebellion to cripple their resources and quell the insurrection .... Martial lawcannot arise from a threatened invasion. The necessity must be actual and present; the invasion real,such as effectively closes the courts and deposes the civil administration. (60)
The government had argued in the alternative that Milligan could be held as a prisoner of war"as if he had been taken in action with arms in his hands," (61) and thus excluded fromthe privileges of a statute requiring courts to free persons detained without charge. The governmentargued:
Finally, if the military tribunal has no jurisdiction, thepetitioner may be held as a prisoner of war, aiding with arms the enemies of the United States, andheld, under the authority of the United States, until the war terminates, then to be handed over by themilitary to the civil authorities, to be tried for his crimes under the acts of Congress, and before thecourts which he has selected. (62)
Milligan, however, argued "that it had been 'wholly out of his power to have acquired belligerentrights, or to have placed himself in such relation to the government as to have enabled him to violatethe laws of war,'" (63) ashe was charged. The Court appears to have agreed with Milligan, replying:
It is not easy to see how he can be treated as a prisonerof war, when he lived in Indiana for the past twenty years, was arrested there, and had not been,during the late troubles, a resident of any of the states in rebellion. If in Indiana he conspired withbad men to assist the enemy, he is punishable for it in the courts of Indiana; but, when tried for theoffence, he cannot plead the rights of war; for he was not engaged in legal acts of hostility againstthe government, and only such persons, when captured, are prisoners of war. If he cannot enjoy theimmunities attaching to the character of a prisoner of war, how can he be subject to their pains andpenalties? (64)
In Quirin , the Supreme Court distinguished its holding from Milligan, finding that thepetitioners were enemy belligerents and that the charge made out a valid allegation of an offenseagainst the law of war for which the President was authorized to order trial by a militarycommission. (65) TheCourt noted that Milligan had not been a part of or associated with the armed forces of the enemy,and therefore was a non-belligerent, not subject to the law of war. (66) The Sons of Liberty, itseems, did not qualify as a belligerent for the purposes of the law of war, even though it was allegedto be plotting hostile acts on behalf of the Confederacy. Milligan was interpreted by some statecourts to preclude the trial by military commission of persons accused of participating in guerrillaactivities in Union territory, (67) and despite Congress' efforts to immunize executive officials foractions done under military authority during the Civil War, (68) the Supreme Court ofIllinois upheld damages awarded to Madison Y. Johnson, who, accused of being "a belligerent" butnever charged with any offense, was confined under orders issued by the Secretary of War. (69) 
The Hamdi Court found that Milligan did not apply to a U.S. citizen captured in Afghanistan. Justice O'Connor wrote that Milligan 
does not undermine our holding about the Government'sauthority to seize enemy combatants, as we define that term today. In that case, the Court maderepeated reference to the fact that its inquiry into whether the military tribunal had jurisdiction to tryand punish Milligan turned in large part on the fact that Milligan was not a prisoner of war, but aresident of Indiana arrested while at home there. That fact was central to its conclusion. HadMilligan been captured while he was assisting Confederate soldiers by carrying a rifle against Uniontroops on a Confederate battlefield, the holding of the Court might well have been different. TheCourt's repeated explanations that Milligan was not a prisoner of war suggest that had these differentcircumstances been present he could have been detained under military authority for the duration ofthe conflict, whether or not he was a citizen. (70)

		Moyer v. Peabody

The government cites Moyer v. Peabody (71) to support its contention that the President has the authorityduring war, subject only to extremely deferential review by the courts, to detain an individual thegovernment believes to be dangerous or likely to assist the enemy. (72) The government furtherasserts that the case supports the historical "unavailability" of due process rights, such as the rightto counsel, in the case of enemy combatants. (73) In Moyer , the Supreme Court declined to grant relief to theplaintiff in a civil suit against the governor of Colorado based on the former's detention withoutcharge during a miners' strike (deemed by the governor to be an insurrection), stating:
So long as such arrests are made in good faith and inthe honest belief that they are needed in order to head the insurrection off, the governor is the finaljudge and cannot be subjected to an action after he is out of office, on the ground that he had notreasonable ground for his belief. (74)
The Court based its views in part on the laws and constitution of the state of Colorado, whichempowered the governor to repel or suppress insurrections by calling out the militia, which the Courtnoted, envisioned the 
ordinary use of soldiers to that end; that he may killpersons who resist, and, of course, that he may use the milder measure of seizing the bodies of thosewhom he considers to stand in the way of restoring peace. Such arrests are not necessarily forpunishment, but are by way of precaution, to prevent the exercise of hostile power. (75) 
The Court further clarified:
If we suppose a governor with a very long term ofoffice, it may be that a case could be imagined in which the length of the imprisonment would raisea different question. But there is nothing in the duration of the plaintiff's detention or in theallegations of the complaint that would warrant submitting the judgment of the governor to revisionby a jury. It is not alleged that his judgment was not honest, if that be material, or that the plaintiffwas detained after fears of the insurrection were at an end. 
Based on the context of the case, the holding may be limited to actual battles and situations ofmartial law where troops are authorized to use deadly force as necessary. (76) While the Court notes that"[p]ublic danger warrants the substitution of executive process for judicial process," (77) it also noted that 
[t]his was admitted with regard to killing men in theactual clash of arms; and we think it obvious, although it was disputed, that the same is true oftemporary detention to prevent apprehended harm. As no one would deny that there was immunityfor ordering a company to fire upon a mob in insurrection, and that a state law authorizing thegovernor to deprive citizens of life under such circumstances was consistent with the 14thAmendment, we are of opinion that the same is true of a law authorizing by implication what wasdone in this case. (78)
It may also be argued that, as a claim for civil damages rather than a direct challenge in theform of a petition for habeas corpus , the Moyer case does not stand for a general executive authorityto detain individuals deemed to be dangerous, without the ordinary constitutional restrictions. Asan interpretation of Colorado's constitution rather than that of the United States, the decision maynot apply to Presidential action. Other courts have reached the opposite conclusion -- that thosewrongfully detained by order of the President may recover damages from their captors. (79) 

	U.S. Practice - Detention of Enemies on U.S. Territory

The following sections give a brief treatment of the twentieth-century history of theinternment of individuals who are deemed "enemies" or determined to be too dangerous to remainat liberty during a national emergency. A survey of the history reveals that persons who areconsidered likely to act as an enemy agent on U.S. territory traditionally have been treated as alienenemies rather than prisoners of war or "enemy combatants" by the military, even when theindividuals were members of the armed forces of enemy nations, although in the latter case theymight also be tried by military commission or court-martial, if accused of a crime. Persons actingwithin the territory of the United States on behalf of an enemy state who were not members of thearmed forces of that state, including American citizens accused of spying or sabotage, have beentried in federal court. Individuals captured on the battlefield abroad have been handled in accordancewith government regulations interpreting the law of war. (80) 

		Internment of Enemy Aliens during World War I

The Alien Enemy Act was originally enacted in 1798 as part of the Alien and SeditionAct, (81) but saw greateruse during World War I than in previous wars. (82) The statute grants the President broad authority, during a declaredwar or presidentially proclaimed "predatory invasion," to institute restrictions affecting alienenemies, including possible detention and deportation. On April 6, 1917, the date Congress declaredwar against Germany, President Wilson issued a Proclamation under the Alien Enemy Act warningalien enemies against violations of the law or hostilities against the United States. (83) Offenders would besubject not only to the applicable penalties prescribed by the domestic laws they violated, but wouldalso be subject to restraint, required to give security, or subject to removal from the United Statesunder regulations promulgated by the President. (84) 
The government urged the courts to uphold the constitutionality of the act as a properexercise of Congress' power over the persons and property of alien enemies found on U.S. territoryduring war, a power it argued derives from the power of Congress to declare war and make rulesconcerning captures on land and water, (85) and which was also consistent with the powers residing insovereign nations under international law. The law was vital to national security because "[a]n armyof spies, incendiaries, and propagandists may be more dangerous than an army of soldiers." (86) The President reportedto Congress a list of 21 instances of "improper activities of German officials, agents, andsympathizers in the United States" prior to the declaration of war. (87) The government furtherargued that the statute did not require a hearing prior to internment, because the power and duty ofthe President was to act to prevent harm in the context of war, which required the ability to act basedon suspicion rather than only on proven facts. (88) 
While the act would permit regulations affecting all persons within the statutory definitionof alien enemy, (89) it wasthe practice of the United States to apply restrictions only to alien enemies who were found toconstitute an active danger to the state. (90) Aliens affected by orders promulgated under the act did not haverecourse to the courts to object to the orders on the grounds that the determination was not made inaccordance with due process of law, but could bring habeas corpus petitions to challenge their statusas enemy aliens. (91) 
In at least two instances, enemy spies or saboteurs entered the territory of the United Statesand were subsequently arrested. Pablo Waberski admitted to U.S. secret agents to being a spy sentby the Germans to "blow things up in the United States." Waberski, who was posing as a Russiannational, was arrested upon crossing the border from Mexico into the United States and charged with"lurking as a spy" under article 82 of the Articles of War. (92) Attorney General T. W. Gregory opined in a letter to thePresident that the jurisdiction of the military to try Waberski by military tribunal was improper,noting that the prisoner had not entered any camp or fortification, did not appear to have been inEurope during the war, and thus could not have come through the fighting lines or field of militaryoperations. (93) Anensuing disagreement between the Departments of War and Justice over the respective jurisdictionsof the FBI and military counterintelligence to conduct domestic surveillance was resolved bycompromise. (94) 
Waberski, an officer of the German armed forces whose real name turned out to be LotharWitzke, was sentenced to death by a military commission. Subsequently, the new Attorney General,A. Mitchell Palmer, reversed the earlier AG opinion based on a new understanding of the facts ofthe case, including proof that the prisoner was a German citizen and that there were militaryencampments close to the area where he was arrested. (95) President Wilson commuted Witzke's sentence to lifeimprisonment at hard labor in Fort Leavenworth and later pardoned him, possibly due to lingeringdoubts about the propriety of the military tribunal's jurisdiction to try the accused spy, (96) even though Congress haddefined the crime of spying and provided by statute that it was an offense triable by militarycommission. (97) 
The question of military jurisdiction over accused enemy spies arose again in the case of United States ex rel. Wessels v. McDonald , (98) a habeas corpus proceeding brought by Herman Wessels tochallenge his detention by military authorities while he was awaiting court-martial for spying. Theaccused was an officer in the German Imperial Navy who used a forged Swiss passport to enter theUnited States and operated as an enemy agent in New York City. He was initially detained as analien enemy pursuant to a warrant issued in accordance with statute. He contested his detention onthe basis that the port of New York was not in the theater of battle and courts in New York wereopen and functioning, arguing Milligan required that he be tried by an Article III court. (99) The court found that itsinquiry was confined to determining whether jurisdiction by court martial was valid, which itanswered affirmatively after examining relevant statutes and finding that, under international law,the act of spying was not technically a crime. (100) The court concluded that the constitutional safeguardsavailable to criminal defendants did not apply, noting that whoever "joins the forces of an enemyalien surrenders th[e] right to constitutional protections." The Supreme Court did not have theopportunity to address the merits of the case, having dismissed the appeal per stipulation of theparties. (101) However,two American citizens who were alleged to have conspired to commit espionage with Wessels weretried and acquitted of treason in federal court, (102) and subsequently released. 
In 1918, a bill was introduced in the Senate to provide for trial by court-martial of personsnot in the military who were accused of espionage, sabotage, or other conduct that could hurt the wareffort. (103) In a letterto Representative John E. Raker explaining his opposition to the idea, Attorney General T.W.Gregory provided statistics about war-related arrests and prosecutions. (104) According to the letter,of 508 espionage cases that had reached a disposition, 335 had resulted in convictions, 31 personswere acquitted, and 125 cases were dismissed. (105) Sedition and disloyalty charges had yielded 110 convictionsand 90 dismissals or acquittals. (106) Acknowledging that the statistics were incomplete, theAttorney General concluded that the statistics did not show a cause for concern. (107) He also reiterated hisposition that trial of civilians for offenses committed outside of military territory by court-martialwould be unconstitutional, and attributed the complaints about the inadequacies of the laws or theirenforcement to:
the fact that people, under the emotional stress of thewar, easily magnify rumor into fact, or treat an accusation of disloyalty as though it were equal toproof of disloyalty. No reason, however, has as yet developed which would justify punishing menfor crime without trying them in accordance with the time-honored American method of arriving atthe truth. (108)
The record does not disclose any mention of the option of deeming suspects to be unlawfulcombatants based on their alleged association with the enemy, detaining them without any kind oftrial.

		Internment of Enemies during World War II

During the Second World War, President Roosevelt made numerous proclamations underthe Alien Enemy Act for the purpose of interning aliens deemed dangerous or likely to engage inespionage or sabotage. (109) At the outset of the war, the internments were effected undercivil authority of the Attorney General, who established "prohibited areas" in which no aliens ofJapanese, Italian, or German descent were permitted to enter or remain, as well as a host of otherrestraints on affected aliens. The President, acting under statutory authority, delegated to theAttorney General the authority to prescribe regulations for the execution of the program. AttorneyGeneral Francis Biddle created the Alien Enemy Control Unit to review the recommendations ofhearing boards handling the cases of the more than 2,500 enemy aliens in the temporary custody ofthe Immigration and Naturalization Service (INS). (110) 
In February of 1942, the President extended the program to cover certain citizens (111) as well as enemyaliens, and turned over the authority to prescribe "military areas" to the Secretary of War, who furtherdelegated the responsibilities under the order with respect to the west coast to the CommandingGeneral of the Western Defense Command. The new order, Executive Order 9066, (112) clearly amended thepolicy established under the earlier proclamations regarding aliens and restricted areas, but did notrely on the authority of Alien Enemy Act, as the previous proclamations had done. (113) Although theDepartment of Justice denied that the transfer of authority to the Department of War was motivatedby a desire to avoid constitutional issues with regard to the restriction or detention of citizens, theHouse Select Committee Investigating National Defense Migration found the shift in authoritysignificant, as it appeared to rely on the nation's war powers directly, and could find no support inthe Alien Enemy Act with respect to citizens. (114) The summary exercise of authority under that act to restrainaliens was thought by the Committee to be untenable in the case of U.S. citizens, and the WarDepartment felt congressional authorization was necessary to provide authority for itsenforcement. (115) 
Congress granted the War Department's request, enacting with only minor changes theproposed legislation providing for punishment for the knowing violation of any exclusion orderissued pursuant to Executive Order 9066 or similar executive order. (116) A policy of massevacuation from the West Coast of persons of Japanese descent -- citizens as well as aliens --followed, which soon transformed into a system of compulsive internment at "relocationcenters." (117) Personsof German and Italian descent (and others) were treated more selectively, receiving prompt (thoughprobably not full and fair) loyalty hearings (118) to determine whether they should be interned, paroled, orreleased. The disparity of treatment was explained by the theory that it would be impossible or tootime-consuming to attempt to distinguish the loyal from the disloyal among persons of Japanesedescent. (119) 
In a series of cases, the Supreme Court limited but did not explicitly strike down theinternment program. In the Hirabayashi case, the Supreme Court found the curfew imposed uponpersons of Japanese ancestry to be constitutional as a valid war-time security measure, even asimplemented against U.S. citizens, emphasizing the importance of congressional ratification of theExecutive Order. (120) Hirabayashi was also indicted for violating an order excluding him from virtually the entire westcoast, but the Court did not review the constitutionality of the exclusion measure because thesentences for the two charges were to run concurrently. (121) Because the restrictions affected citizens solely because oftheir Japanese descent, the Court framed the relevant inquiry as a question of equal protection,asking
whether in the light of all the facts and circumstancesthere was any substantial basis for the conclusion, in which Congress and the military commanderunited, that the curfew as applied was a protective measure necessary to meet the threat of sabotageand espionage which would substantially affect the war effort and which might reasonably beexpected to aid a threatened enemy invasion. (122)
In a concurring opinion, Justice Douglas added that in effect, due process considerations didnot apply to ensure that only individuals who were actually disloyal were affected by the restrictions,even if it were to turn out that only a small percentage of Japanese-Americans were actuallydisloyal. (123) However, he noted that a more serious question would arise if a citizen did not have an opportunityat some point to demonstrate his loyalty in order to be reclassified and no longer subject to therestrictions. (124) 
In Korematsu , (125) the Supreme Court upheld the conviction of an Americancitizen for remaining in his home, despite the fact that it was located on a newly declared "MilitaryArea" and was thus off-limits to persons of Japanese descent. Fred Korematsu also challenged thedetention of Japanese-Americans in internment camps, but the Court declined to consider theconstitutionality of the detention itself, as Korematsu's conviction was for violating the exclusionorder only. The Court, in effect, validated the treatment of citizens in a manner similar to that ofenemy aliens by reading Executive Order 9066 together with the act of Congress ratifying it assufficient authority under the combined war powers of the President and Congress, thus avoidinghaving to address the statutory scope of the Alien Enemy Act. 
In Ex parte Endo , (126) however, decided the same day as Korematsu , the SupremeCourt did not find adequate statutory underpinnings to support the internment of loyal citizens. TheCourt ruled that the authority to exclude persons of Japanese ancestry from declared military areasdid not encompass the authority to detain concededly loyal Americans. Such authority, it found,could not be implied from the power to protect against espionage and sabotage during wartime. (127) The Court declined todecide the constitutional issue presented by the evacuation and internment program, insteadinterpreting the executive order, along with the act of March 27, 1942 (congressional ratification ofthe order), (128) narrowly to give it the greatest chance of surviving constitutional review. (129) Accordingly, the Courtnoted that detention in Relocation Centers was not mentioned in the statute or executive order, butwas developed during the implementation of the program. As such, the authority to detain citizenscould only be found by implication in the act, and must therefore be found to serve the endsCongress and the President had intended to reach. Since the detention of a loyal citizen did notfurther the campaign against espionage and sabotage, it could not be authorized by implication. 
The Court avoided the question of whether internment of citizens would be constitutionallypermissible where loyalty were at issue or where Congress explicitly authorized it, but the Court'suse of the term "concededly loyal" to limit the scope of the finding may be read to suggest that thereis a Fifth Amendment guarantee of due process applicable to a determination of loyalty ordangerousness. While the Fifth Amendment would not require the same process that is due in acriminal case, it would likely require at least reasonable notice of the allegations and an opportunityfor the detainee to be heard. 
At least one American with no ethnic ties to or association with an enemy country wassubjected to an exclusion order issued pursuant to Executive Order 9066. Homer Wilcox, a nativeof Ohio, was excluded from his home in San Diego and removed by military force to Nevada,although the exclusion board had determined that he had no association with any enemy and wasmore aptly described as a "harmless crackpot." (130) He was the manager of a religious publication that preachedpacifism, and was indicted along with several others for fraud in connection with thepublication. (131) Thedistrict court awarded damages in favor of Wilcox, but the circuit court reversed, finding theexclusion within the authority of the military command under Executive Order 9066 and 18 U.S.C.Â§ 1383, and holding that 
the evidence concerning plaintiff's activities andassociations provided a reasonable ground for the belief by defendant ... that plaintiff had committedacts of disloyalty and was engaged in a type of subversive activity and leadership which mightinstigate others to carry out activities which would facilitate the commission of espionage andsabotage and encourage them to oppose measures taken for the military security of Military AreasNos. 1 and 2, and that plaintiff's presence in the said areas from which he had been excluded wouldincrease the likelihood of espionage and sabotage and would constitute a danger to military securityof those areas. (132)
The court also found that the act of Congress penalizing violations of military orders underExecutive Order 9066 did not preclude General De Witt from using military personnel to forciblyeject Wilcox from his home. (133) 
The Japanese internment program has since been widely discredited, (134) the convictions of somepersons for violating the orders have been vacated, (135) and the victims have received compensation, (136) but theconstitutionalityof detention of citizens during war who are deemed dangerous has never expressly been ruled perse unconstitutional. (137) In the cases of citizens of other ethnic backgrounds who wereinterned or otherwise subject to restrictions under Executive Order 9066, courts played a role indetermining whether the restrictions were justified, sometimes resulting in the removal ofrestrictions. (138) Because these persons were afforded a limited hearing to determine their dangerousness, a court laterruled that the Equal Protection Clause of the Constitution did not require that they receivecompensation equal to that which Congress granted in 1988 to Japanese-American internees. (139) 
It may be argued that Hirabayashi and the other cases validating Executive Order 9066 (upto a point) support the constitutionality of preventive detention of citizens during war, at least insofaras the determination of dangerousness of the individual interned is supported by some evidence andsome semblance of due process is accorded the internee. However, it was emphasized in these casesthat Congress had specifically ratified Executive Order 9066 by enacting 18 U.S.C. Â§ 1383,providing a penalty for violation of military orders issued under the Executive Order. Thus, eventhough the restrictions and internments occurred in the midst of a declared war, a presidential ordercoupled with specific legislation appear to have been required to validate the measures. Theinternment of Japanese-American citizens without individualized determination of dangerousnesswas found not to be authorized by the Executive Order and ratifying legislation (the Court therebyavoiding the constitutional issue), although the President had issued a separate Executive Order toset up the War Relocation Authority (140) and Congress had given its tacit support for the internmentsby appropriating funds for the effort. (141) 
The only persons who were treated as enemy combatants pursuant to Proclamation No.2561 (142) weremembers of the German military who had been captured after landing on U.S. beaches from Germansubmarines. (143) Collaborators and persons who harbored such saboteurs were tried in federal courts for treason orviolations of other statutes. (144) Hans Haupt, the father of one of the saboteurs, was sentencedto death for treason, but this sentence was overturned on the ground that procedures used during thetrial violated the defendant's rights. (145) On retrial, Haupt was sentenced to life imprisonment, but hissentence was later commuted on the condition that he leave the country. Another person chargedwith treason for his part in the saboteurs' conspiracy, Helmut Leiner, was acquitted of treason butthen interned as an enemy alien. (146) Anthony Cramer, an American citizen convicted of treasonfor assisting one of the saboteurs to carry out financial transactions, had his conviction overturnedby the Supreme Court on the grounds that the overt acts on which the charge was based wereinsufficient to prove treason. (147) Emil Krepper, a pastor living in New Jersey, came undersuspicion because his name was found printed in secret ink on the saboteur's handkerchief, althoughhe never met with any of the saboteurs. He was indicted for violating TWEA and receiving a salaryfrom the German government without reporting his activity as a foreign agent. (148) 
These cases involving collaborators with the Quirin eight, as well as other unrelated casesof sabotage or collaboration with the enemy during World War II, did not result in any militarydeterminations that those accused were enemy combatants. It is thus not clear what kind ofassociation with Germany or with other enemy saboteurs, short of actual membership in the Germanarmed forces, would have enabled the military to detain them as enemy combatants under the lawof war. (149) It appearsthat Quirin was not interpreted at the time as having established executive authority to detain personsbased on their alleged hostile intent, particularly without any kind of a trial.
After the Quirin decision, the Attorney General asked Congress to pass legislation tostrengthen criminal law relating to internal security during wartime. (150) Attorney GeneralBiddle wrote that new law was necessary to cover serious gaps and inadequacies in criminal law,which he argued did not provide sufficient punishment for hostile enemy acts perpetrated on theterritory of the United States. (151) The House Committee on the Judiciary endorsed the proposedWar Security Act, pointing to the fact that it had been necessary to try the eight Nazi saboteurs bymilitary commission due to the inadequacy of the penal code to punish the accused for acts that hadnot yet been carried out. (152) It also suggested that military jurisdiction might beunavailable to try enemy saboteurs who had not "landed as part of a small invasion bent upon actsof illegal hostilities." (153) The bill passed in the House of Representatives, but was notsubsequently taken up in the Senate.

		The Cold War

After the close of World War II, the Congress turned its attention to the threat ofcommunism. Recognizing that the Communist Party presented a different kind of threat from thatof a strictly military attack, members of Congress sought to address the internal threat withinnovative legislation. (154) Introduced in the wake of the North Korean attack on SouthKorea, the Internal Security Act (ISA) of 1950 (155) was the culmination of many legislative efforts to providemeans to fight what was viewed as a foreign conspiracy to infiltrate the United States and overthrowthe government by means of a combination of propaganda, espionage, sabotage, and terroristacts. (156) TheAttorney General presented to the Congress a draft bill that would strengthen the espionage statutes,amend the Foreign Agents Registration Act, and provide authority for U.S. intelligence agencies tointercept communications. (157) According to the Attorney General, the legislation wasnecessary because
[t]he swift and more devastating weapons of modernwarfare coupled with the treacherous operations of those who would weaken our country internally,preliminary to and in conjunction with external attack, have made it imperative that we strengthenand maintain an alert and effective peacetime vigilance. (158)
S. 4037 combined the proposed legislation with other bills related to nationalsecurity, including measures to exclude and expel subversive aliens, to detain or supervise aliensawaiting deportation, and to deny members of communist organizations the right to travel on a U.S.passport. The bill also contained a requirement for Communist-controlled organizations andCommunist-front organizations (159) to register as such. President Truman and opponents of theso-called McCarran Act thought the registration requirements and other provisions likely to be eitherunconstitutional or ineffective, and expressed concern about possible far-reaching civil libertiesimplications. (160) 
Opponents of the McCarran Act sought to substitute a new bill designed to address thesecurity concerns in what they viewed as a more tailored manner. Senator Kilgore introduced theEmergency Detention Act (161) (Kilgore bill) to authorize the President to declare a nationalemergency under certain conditions, during which the Attorney General could enact regulations forthe preventive incarceration of persons suspected of subversive ties. At the time of the debate, 18U.S.C. Â§ 1383 was still on the books and would have ostensibly supported the declaration of militaryareas and the enforcement of certain restrictions against aliens or citizens deemed dangerous. Proponents of the Kilgore bill argued that the proposed legislation would create a program forinternment of enemies that would contain sufficient procedural safeguards to render it invulnerableto court invalidation based on Ex parte Endo . (162) 
The final version of the ISA contained both the McCarran Act and the Emergency DetentionAct. President Truman vetoed the bill, voicing his continued opposition to the McCarran Act. ThePresident did not take a firm position with regard to the Emergency Detention Act, stating that 
it may be that legislation of this type should be on thestatute books. But the provisions in [the ISA] would very probably prove ineffective to achieve theobjective sought, since they would not suspend the writ of habeas corpus, and under our legal systemto detain a man not charged with a crime would raise serious constitutional questions unless the writof habeas corpus were suspended. (163)
The President recommended further study on the matter of preventive detention for national securitypurposes. Congress passed the ISA over the President's veto. (164) 
The Emergency Detention Act, Title II of the ISA, authorized the President to declare an"Internal Security Emergency" in the event of an invasion of the territory of the United States or itspossessions, a declaration of war by Congress, or insurrection within the United States in aid of aforeign enemy, where the President deemed implementation of the measures "essential to thepreservation, protection and defense of the Constitution." (165) The act authorized themaintenance of the internment and prisoner-of-war camps used during World War II for use duringsubsequent crises, and authorized the Attorney General, during national emergencies under the act,to issue warrants for the apprehension of "those persons as to whom there is a reasonable ground tobelieve that such persons probably will engage in, or conspire to engage in acts of sabotage orespionage." Detainees were to be taken before a preliminary hearing officer within 48 hours of theirarrest, where each detainee would be informed of the grounds for his detention and of his rights,which included the right to counsel, the privilege against self-incrimination, the right to introduceevidence and cross-examine witnesses. (166) The Attorney General was required to present evidence to thedetainee and to the hearing officer or board "to the fullest extent possible consistent with nationalsecurity." (167) Evidence that could be used to determine whether a person could be detained as dangerous includedevidence that a person received training from or had ever committed or conspired to commitespionage or sabotage on behalf of an entity of a foreign Communist party or the Communist Partyof the United States, or any other group that seeks the overthrow of the government of the UnitedStates by force. (168) 
No internal emergencies were declared pursuant to the Emergency Detention Act, despite theUnited States' involvement in active hostilities against Communist forces in Korea and Vietnam andthe continued suspicion regarding the existence of revolutionary and subversive elements within theUnited States. (169) Nevertheless, the continued existence of the act aroused concern among many citizens, who believedthe act could be used as an "instrumentality for apprehending and detaining citizens who holdunpopular beliefs and views." (170) Several bills were introduced to amend or repeal the act. (171) The JusticeDepartment supported the repeal of the act, opining that the potential advantage offered by the statutein times of emergency was outweighed by the benefits that repealing the detention statute wouldhave by allaying the fears and suspicions (however unfounded they might have been) of concernedcitizens. (172) 
Congress decided to repeal the Emergency Detention Act in toto in 1971, and enacted in itsplace a prohibition on the detention of American citizens except pursuant to an act of Congress. (173) The new language wasintended to prevent a return to the pre-1950 state of affairs, in which "citizens [might be] subject toarbitrary executive authority" without prior congressional action. (174) Executive Order 9066was formally rescinded in 1976. (175) Congress repealed 18 U.S.C. Â§ 1383 later that year. (176) 
It may be argued that Congress, in passing the Emergency Detention Act in 1950, waslegislating based on its constitutional war powers, to provide for the preventive detention duringnational security emergencies of those who might be expected to act as enemy agents, though nottechnically within the definition of "alien enemies." It does not, therefore, appear that Congresscontemplated that the President already had the constitutional power to declare such individuals tobe enemy combatants, subject to detention under the law of war, except under very narrowcircumstances. The much earlier legislative history accompanying the passage of the Alien EnemyAct may also be interpreted to suggest that the internment of enemy spies and saboteurs in war wasnot ordinarily a military power that could be exercised by the President alone, or at least, not a powerwith which Congress could not constitutionally interfere. (177) 
The repeal of the Emergency Detention Act and the enactment of 18 U.S.C. Â§ 4001(a) maybe interpreted to preclude the detention of American citizens as enemy agents or traitors unlessconvicted of a crime. If the law of war traditionally supports the detention of such persons as enemycombatants or unlawful combatants, it may be questioned why such an approach has not beenutilized during past conflicts, during which the internal security risk of hostile action by "fifthcolumnists," spies, and saboteurs was frequently perceived to equal the danger of military clasheson the battlefield.

	Recent and Current "Enemy Combatant" Cases

One U.S. citizen is known to remain in custody in the United States as an enemy combatant;the other has been released. It was reported that one Canadian citizen was being held in U.S. militarycustody in the United States after his arrest by the Canadian Security Intelligence Service. (178) It is unclear whetherthe man, Mohamed Mansour Jabarah, is considered an "enemy combatant," but he reportedly washeld for interrogation and not charged with any offense. A Qatari national who was lawfully presentin the United States has also been declared an "enemy combatant" and turned over to militarycustody. The man, Ali Saleh Kahlah Al-Marri, was originally detained as a material witness onDecember 12, 2001, in connection with the investigation into the attacks of September 11, 2001. He was later charged with credit card fraud and scheduled to stand trial beginning July 21, 2003. However, on June 23, 2003, President Bush designated him an "enemy combatant" and directed thathe be transferred to the Naval Consolidated Brig in Charleston, South Carolina, where he is currentlybeing held. His attorneys filed a petition for habeas corpus on his behalf in the District Court forthe Central District of Illinois, which dismissed the petition for improper venue. (179) 

		The Case of Yaser Esam Hamdi

Hamdi's case may be likened to Territo in that he was captured on a field of battle and wasnot charged with committing any offense. In Territo, the court cited the 1929 Geneva ConventionRelative to the Treatment of Prisoners of War as the legal authority for the detention of the petitioneras a prisoner of war, and the petitioner did not dispute that he had served as a member of the Italianarmed forces, with which the United States was then at war. The sole question before the court waswhether a U.S. citizen could lawfully be treated as a prisoner of war under U.S. law and the law ofwar. Territo did not contest his capture as a war prisoner or claim that his rights under the 1929Geneva Convention had been violated.
Hamdi, however, reportedly claimed that he is not a member of Al Qaeda or the Taliban andwas present in Afghanistan only to provide humanitarian assistance. (180) The Fourth Circuitagreed that "[i]t has long been established that if Hamdi is indeed an 'enemy combatant' who wascaptured during hostilities in Afghanistan, the government's present detention of him is a lawfulone." (181) The FourthCircuit ordered the district judge to dismiss the petition, holding essentially that a determination bythe military that an individual is an enemy combatant is conclusive, so long as it is supported bysome evidence. (182) 
In the first interlocutory appeal, the Fourth Circuit vacated a district court order that theprisoner be provided immediate, unmonitored access to an attorney, urging the district court to showdeference to the government in its examination of the issue, but expressly declining to embrace the"sweeping proposition" that "with no meaningful judicial review, any American citizen alleged tobe an enemy combatant could be detained indefinitely without charges or counsel on thegovernment's say-so." (183) On remand, the district court ordered the government toprovide additional information to support its conclusion that Hamdi is an enemy combatant. (184) The court found thepetitioner to be entitled to due process of law under the Fifth Amendment, and expressed the intentto inquire into the authority of the person making the determination of Hamdi's status, whether thescreening criteria used to determine such status meet due process requirements, the national securityaims served by his continued detention, and whether the relevant military regulations andinternational law require a different procedure. (185) 
On appeal to the Fourth Circuit, the government argued that the proof already submitted tothe court, which consisted of a declaration by Michael Mobbs, a special advisor to the UnderSecretary of Defense for Policy, was sufficient as a matter of law to establish the legality of thedetention. (186) TheFourth Circuit agreed, (187) declaring that since the Hamdi petition conceded that Hamdihad been seized in Afghanistan during a time of military hostilities, there were no disputed facts thatwould necessitate the evidentiary hearing ordered by the district court, which could also involve asignificant interference with the war effort. (188) The court also disposed of the legal arguments put forth onHamdi's behalf, finding that 18 U.S.C. Â§ 4001(a) does not apply and that the Geneva Conventionsare non-self-executing treaties and therefore do not give individuals a right of action. The courtvacated the production order issued by the district court and ordered the petition to be dismissed.
The Supreme Court vacated the Fourth Circuit decision and remanded it to allow Hamdi ameaningful opportunity to contest his status as an "enemy combatant." However, the Justices couldnot reach a consensus for the rationale. Justice O'Connor, joined by the Chief Justice as well asJustices Kennedy and Breyer wrote the opinion for the Court. The plurality found that althoughdetention such as Hamdi's is an ordinary aspect of war-fighting and thus was authorized byimplication by the AUMF, "due process demands that a citizen held in the United States as an enemycombatant be given a meaningful opportunity to contest the factual basis for that detention beforea neutral decisionmaker. (189) Declaring that "a state of war is not a blank check for thePresident when it comes to the rights of the Nation's citizens," the Court rejected the Government'sview that separation of powers principles "mandate a heavily circumscribed role for the courts insuch circumstances." (190) It also rejected the Fourth Circuit's characterization of thecircumstances surrounding Hamdi's seizure as "undisputed," (191) and held that for Hamdito continue to be detained as an enemy combatant, (192) he would need to be found to have been "part of or supportingforces hostile to the United States or coalition partners" and "engaged in an armed conflict againstthe United States," (193) and that his detention was authorized only so long as activehostilities continue in Afghanistan.
At the same time, the plurality did not call for a hearing that would comport with all of therequirements the Constitution applies to a criminal trial. Instead, a balancing test to weigh the riskof erroneous deprivation of a detainee's liberty interest against the government's interest in fightinga war may suffice. Such a procedure, the plurality suggested, could eliminate certain procedures thathave "questionable additional value in light of the burden on the Government," (194) so that "enemycombatant proceedings may be tailored to alleviate their uncommon potential to burden theExecutive at a time of ongoing military conflict." (195) However, at least in the case of citizens, the "some evidence"standard urged by the government would be insufficient. (196) 
The plurality emphasized that its interpretation of the AUMF's grant of authority for the useof "necessary and appropriate force" is "based on longstanding law-of-war principles," but that "[i]fthe practical circumstances of a given conflict are entirely unlike those of the conflicts that informedthe development of the law of war, that understanding may unravel." (197) Based on theconventional understanding of the conflict as limited to the hostilities in Afghanistan, the pluralitystated that "indefinite detention for the purpose of interrogation is not authorized." (198) 
The United States may detain, for the duration of thesehostilities, individuals legitimately determined to be Taliban combatants who "engaged in an armedconflict against the United States." If the record establishes that United States troops are stillinvolved in active combat in Afghanistan, those detentions are part of the exercise of "necessary andappropriate force," and therefore are authorized by the [AUMF].
Justice Souter, joined by Justice Ginsburg, agreed that Hamdi is entitled to due process,including the right to counsel (but without the qualifications suggested by Justice O'Connor), andjoined the plurality to provide sufficient votes to vacate the decision below. (199) However, finding noexplicit authority in the AUMF (or other statutes) to detain persons as enemy combatants, they wouldhave determined that 18 U.S.C. Â§ 4001(a) precludes the detention of American citizens as enemycombatants altogether. Justice Scalia, joined by Justice Stevens, dissented from the pluralityopinion, arguing that the detention of a U.S. citizen under the circumstances described could onlyoccur after a trial on criminal charges or where Congress has suspended the Writ of Habeas Corpus. Only Justice Thomas would have affirmed the decision below.

		The Case of Jose Padilla

The Supreme Court did not resolve the case of Jose Padilla, who was arrested in Chicago andinitially alleged to be involved in a plot to detonate a "dirty bomb." Instead, a majority of fiveJustices vacated the Second Circuit's opinion favorable to Padilla based on the lack ofjurisdiction. (200) FourJustices would have found jurisdiction based on the "exceptional circumstances" of the case (201) and affirmed theholding below that detention is prohibited under 18 U.S.C. Â§ 4001(a). The dissenters indicated theymight find preventive detention to be acceptable under some circumstances:
Executive detention of subversive citizens, likedetention of enemy soldiers to keep them off the battlefield, may sometimes be justified to preventpersons from launching or becoming missiles of destruction. It may not, however, be justified bythe naked interest in using unlawful procedures to extract information. Incommunicado detentionfor months on end is such a procedure. Whether the information so procured is more or less reliablethan that acquired by more extreme forms of torture is of no consequence. For if this Nation is toremain true to the ideals symbolized by its flag, it must not wield the tools of tyrants even to resistan assault by the forces of tyranny. (202)
The case is now in the Fourth Circuit. The District Court for the District of South Carolinagranted Padilla's motion for summary judgment and ordered the government to release Padilla frommilitary detention, while suggesting Padilla could be kept in civilian custody if charged with a crimeor determined to be a material witness. Padilla's attorneys had based their argument on thedissenting opinion of four Supreme Court Justices, who would have found Padilla's detention barredby the Non-Detention Act, and the language in Hamdi seemingly limiting the scope of authorizationto combatants captured in Afghanistan. The government argued that Padilla's detention is coveredunder the Hamdi decision's interpretation of the AUMF because he is alleged to have attended anAl Qaeda training camp in Afghanistan before traveling to Pakistan and then to the UnitedStates, (203) apparentlybased on information obtained from interrogations of Padilla and other persons detained as "enemycombatants." The judge disagreed, finding that express authority from Congress would be necessaryand that the AUMF contains no such authority:
[S]ince Petitioner's alleged terrorist plans were thwartedwhen he was arrested on the material witness warrant, the Court finds that the President's subsequentdecision to detain Petitioner as an enemy combatant was neither necessary nor appropriate. (204)
Accordingly, the court found that Padilla's detention is barred by 18 U.S.C. Â§ 4001(a).
The government further argued that even if Congress had not intended to permit the captureand detention of persons outside of the battlefield, the President's interpretation and application ofthe AUMF is entitled to great deference because he was operating under a broad grant of authorityfrom Congress in an area where he "possesses independent constitutional authority." (205) The court was notpersuaded:
Certainly Respondent does not intend to argue here that,just because the President states that Petitioner's detention is "consistent with the laws of the UnitedStates, including the Authorization for Use of Military Force" that makes it so. Not only is such astatement in direct contravention to the well settled separation of powers doctrine, it is simply notthe law. Moreover, such a statement is deeply troubling. If such a position were ever adopted by thecourts, it would totally eviscerate the limits placed on Presidential authority to protect the citizenry'sindividual liberties. (206)
The court disagreed that the President has inherent authority as Commander-in-Chief of theArmed Forces to determine wartime measures, quoting the Hamdi Court that
[w]here the exercise of Commander-in-Chief powers,no matter how well intentioned, is challenged on the ground that it collides with the powers assignedby the Constitution to Congress, a fundamental role exists for the courts. (207)
The government has appealed the case to the Fourth Circuit Court of Appeals, and has askedfor a stay of the district court's order to release Padilla from military detention. The governmentargues that the facts of Padilla's case are very similar to the facts behind Ex parte Quirin . A federaljudge in the Second Circuit had agreed with this argument, finding that the allegation that Padillatraveled to the United States to detonate a "dirty bomb" on behalf of Al Qaeda, if true, wouldvalidate the government's authority to detain him under military custody. (208) The petitioner arguedthat Quirin is inapposite, given that the eight saboteurs in 1942 were charged and tried by militarycommission, and were given access to an attorney. The Court of Appeals for the Second Circuitagreed with the petitioner, reversing the district court's finding. (209) The district court inthe Fourth Circuit followed the Second Circuit opinion.
Padilla's attorneys argue that the case bears closer resemblance to the Civil War case Ex parte Milligan (210) than toeither the Quirin or Territo cases. The government argues that Milligan is inapposite to the petitionof Padilla on the grounds that Padilla, like petitioners in Quirin , is "a belligerent associated with theenemy who sought to enter the United States during wartime in an effort to aid the enemy'scommission of hostile acts, and who therefore is subject to the laws of war." (211) (This, presumably, isto be contrasted with the case of Milligan, who was a civilian and had never traveled outside the stateof Indiana.) 
The government does not allege that Padilla entered the country illegally or landed as partof a military offensive. (212) In Quirin , the petitioners were members of the German armedforces and admitted to having entered the country surreptitiously by way of German naval submarine. The government's argument appears to presume that there is no relevant difference between thelanding of the German saboteurs and Padilla's entry into the United States by means of a commercialflight, neither under disguise nor using false identification. (213) Under this theory, therelevant factor would appear to be whether the petitioner had ever left the country and traveled to"enemy territory," regardless of how he re-entered the country. 
However, it may be argued that under Quirin , the surreptitious nature of the petitioners'arrival onto the territory of the United States through coastal defenses, by means of enemy vesselsthat would have been lawful targets had the Navy or Coast Guard identified them as such, was amajor determinant of the petitioners' status as enemy combatants. (214) Had they entered thecountry openly and lawfully, they might not have lost their right to be treated as prisoners of war. Padilla's arrival by apparently lawful means arguably has no bearing on whether he is subject tomilitary jurisdiction. 
The government disputes Padilla's claim that the laws of war do not apply to Al Qaeda andthus could never apply to him. The government finds support for the opposite claim in the AUMFand The Prize Cases . (215) Because the President has, by Executive Order, recognizeda state of war against Al Qaeda, the government argues the laws of war must apply, and anyoneassociated with Al Qaeda may therefore properly be deemed to be an "enemy belligerent." However,it is not clear that Al Qaeda is a belligerent under the law of war, because such status wouldordinarily imply belligerent rights that the Administration has been unwilling to concede.
The government argues that Milligan is inapposite; "whereas Milligan was not engaged inlegal acts of hostility against the government, ... the President determined that Padilla engaged inhostile and war-like acts." (216) However, the quoted language from Ex parte Quirin may besomewhat misleading, inasmuch as Milligan was indeed alleged to have engaged in hostile andwarlike acts, but these were not legal acts of hostility because Milligan was not a lawful combatant. Thus, whether Milligan applies may depend on the emphasis placed on the legality of the acts ofhostility of which Milligan was accused, rather than whether Milligan was engaged in acts ofhostility at all. The Milligan opinion seems to view the nature of the legality of the acts to be basedon Milligan's legitimacy as a belligerent rather than the nature of the acts. It may be argued thatPadilla, like Milligan, was not engaged in legal acts of hostility, because he is not a lawfulbelligerent. Milligan's membership in the Sons of Liberty did not secure his legitimacy as abelligerent, but neither did it give the government the right to detain him as a prisoner of war. (217) 
The government further argues that Milligan is inapposite in this case because Milligan, "notbeing a part of or associated with armed forces of the enemy," could not be held as a belligerent,while Padilla, in contrast, is alleged to be associated with the armed forces of the enemy. However,it might be recalled that the government had argued that Milligan was allegedly associated with theConfederate Army, a recognized belligerent, and that he was in effect accused of acting as anunlawful belligerent. (218) Therefore, it may be argued that the important distinction in Quirin was the nature and status of the enemy forces with whom he was associated, rather thanwhether he was associated with a hostile force at all. The petitioners in Quirin were all conceded tobe working for the armed forces of an enemy State in a declared war. What association with theenemy short of membership in its armed forces might have brought the saboteurs under militaryjurisdiction is unclear. 
The continuing validity of Milligan has been questioned by some scholars, even though the Quirin Court declined to overrule it, while others assert that the essential meaning of the case hasonly to do with situations of martial law or, perhaps, civil wars. Furthermore, it has been noted thatthe portion of the plurality in Milligan asserting that Congress could not constitutionally authorizethe President to use the military to detain and try civilians may be considered dicta withcorrespondingly less precedential value, inasmuch as Congress had implicitly denied such authority. However, the Hamdi Court, in distinguishing Milligan from Hamdi , placed emphasis on the fact thatMilligan was not considered a prisoner of war, suggesting that it may recognize the distinctionbetween Milligan and Quirin as a function of combatant status.

	Legal Authority to Detain "Enemy Combatants"

The law of war permits belligerents to seize the bodies and property of enemy aliens. (219) The Administrationhas taken the view that the authority to detain "enemy combatants" belongs to the President alone,and that any interference in that authority by Congress would thus be unconstitutional. (220) However, theConstitution explicitly gives to Congress the power to make rules concerning captures on land andwater, (221) which haslong supported Congress' authority to regulate the capture and disposition of prizes of war as wellas confiscation of property belonging to enemy aliens. (222) 
Both sides point to the Steel Seizure Case (223) to provide a framework for the courts to decide the extent ofthe President's authority. In that Korean War-era case, the Supreme Court declared unconstitutionala presidential order seizing control of steel mills that had ceased production due to a labor dispute,an action justified by President Truman on the basis of wartime exigencies, despite the absence oflegislative authority. Justice Jackson set forth the following oft-cited formula to determine whetherPresidential authority is constitutional:
1. When the President acts pursuant to an express orimplied authorization of Congress, his authority is at its maximum, for it includes all that hepossesses in his own right plus all that Congress can delegate. . . . A seizure executed by thePresident pursuant to an Act of Congress would be supported by the strongest of presumptions andthe widest latitude of judicial interpretation, and the burden of persuasion would rest heavily uponany who might attack it.
2. When the President acts in absence of either acongressional grant or denial of authority, he can only rely upon his own independent powers, butthere is a zone of twilight in which he and Congress may have concurrent authority, or in which itsdistribution is uncertain. Therefore, congressional inertia, indifference or quiescence maysometimes, at least as a practical matter, enable, if not invite, measures on independent presidentialresponsibility. In this area, any actual test of power is likely to depend on the imperatives of eventsand contemporary imponderables rather than on abstract theories oflaw.
3. When the President takes measures incompatiblewith the expressed or implied will of Congress, his power is at its lowest ebb, for then he can relyonly upon his own constitutional powers minus any constitutional powers of Congress over thematter. Courts can sustain exclusive Presidential control in such a case only by disabling theCongress from acting upon the subject. Presidential claim to a power at once so conclusive andpreclusive must be scrutinized with caution, for what is at stake is the equilibrium established by ourconstitutional system. (224)
The parties disagree as to where in this formula the present actions fall. Padilla and Hamdi,and their supporters generally argue that such constitutional authority, if it exists, is dependant uponspecific authorization by Congress, which they argue is missing (or even explicitly denied pursuantto 18 U.S.C. Â§ 4001(a)) in the present circumstances, placing the controversy into the second or thirdcategory above. The government, on the other hand, sees the issue as one that falls squarely into thefirst category, asserting that Congressional authority for the detentions clearly exists, although suchauthority is not strictly necessary. Congressional authority, the government argues, may be foundin the Authorization to Use Force (225) and a provision of title 10, U.S.C., authorizing payment forexpenses related to detention of prisoners of war. Accordingly, the following sections examine theconstitutional authority to take prisoners in war and, if congressional authority is required, whetherCongress has provided it, or, with respect to U.S. citizens, prohibited it.

		The Authorization to Use Force

The government argues, and the Supreme Court has agreed, that the identification anddetention of enemy combatants is encompassed within Congress' express authorization to thePresident "to use force against those 'nations, organizations, or persons he determines' wereresponsible for the September 11, 2001 terrorist attacks." The scope of that authority, however,remains open to debate. Some argue that since Congress only authorized force and did not formallydeclare war, that the absence of language explicitly addressing the detention of either alien enemiesor American citizens captured away from any battlefield cannot be read to imply such authority. (226) 
The government asserts that the lack of a formal declaration of war is not relevant to theexistence of a war and unnecessary to invoke the law of war. While a declaration is unnecessary forthe existence of an armed conflict according to the international law of war, it may be argued thata formal declaration is necessary to determine what law applies domestically, whether to aliens orcitizens. (227) Forexample, the Alien Enemy Act and the Trading with the Enemy Act (TWEA), (228) both of which regulatethe domestic conduct of persons during a war, expressly require a declared war and are not triggeredby the authorization to use force. (229) The Emergency Detention Act, in effect from 1950 to 1971,had similar requirements prior to the invocation of its measures. 
At least one statutory provision in the Uniform Code of Military Justice (UCMJ) that mightauthorize the military to detain certain civilians "in time of war" has been interpreted to mean onlya war declared by Congress. (230) There is also military jurisdiction to try any person "caughtlurking as a spy" during time of war, (231) including citizens, (232) or anyone suspected of aiding or abetting the enemy. (233) It has not been decidedwhether the phrase "in time of war" or reference to "the enemy" in the these articles of the UCMJalso require a declaration of war by Congress; however, the same reasoning applied in Averette (234) and followed in Robb could be found to apply here, at least with respect to persons who may not claim combatant status:
A recognition [that the conflict in Vietnam qualifies asa war in the ordinary sense of the word] should not serve as a shortcut for a formal declaration ofwar, at least in the sensitive area of subjecting civilians to militaryjurisdiction
On the other hand, the Manual for Courts Martial (MCM) defines "time of war" to include declaredwar as well as "a factual determination by the President that the existence of hostilities warrants afinding that a 'time of war'" exists for the punitive portions of the MCM. (235) Likewise, with respectto conduct on the part of military members, the MCM does not restrict references to "enemy" tomean an enemy government or its armed forces. (236) For example, the offense of "misbehavior before the enemy"does not require a declaration of war. (237) It should be noted that these offenses are associated withconduct on the battlefield.
The government notes that its military practice has long been to detain enemy combatantsin conflicts where war was not formally declared and Congress did not expressly authorize thecapture of enemies. However, we are not aware of any modern court ruling as to whether and underwhat circumstances citizens may be held as "enemy combatants," where no formal declaration of warhas been enacted. Hamdi confirms that the authorization to employ ground troops against an enemyarmy necessarily encompasses the authority to capture battlefield enemies, because it is an essentialaspect of fighting a battle. International law does not permit the intentional killing of civilians orsoldiers who are hors de combat, preferring capture as the method of neutralizing enemies on thebattlefield. (238) However, the war powers involving conduct off the battlefield, such as those authorizing thedetention of alien enemies or regulating commerce with the enemy, are not necessarily a vital aspectof the use of the military, and have traditionally been subject to legislation and not implied bycircumstance. For example, the Supreme Court held that the President has no implied authority topromulgate regulations permitting the capture of enemy property during hostilities short of a declaredwar, even where Congress had authorized a "limited" war. (239) 
It may be argued that, because the internment of enemy aliens as potential spies and saboteurspursuant to the Alien Enemy Act (240) requires a declaration of war or a presidential proclamation,it would seem reasonable to infer that the express permission of Congress is necessary for otherforms of military detention of non-military persons within the United States, especially those whoare U.S. citizens. (241) To conclude otherwise would appear to require an assumption that Congress intended in this instanceto authorize the President to detain American citizens under fewer restrictions than apply in the caseof enemy aliens during a declared war. (242) 
However, it might also be argued that the United States is a battlefield in the war againstterrorism in more than just a metaphorical sense. The AUMF appears to authorize the use of forceanywhere in the world, including the territory of the United States, against any persons determinedby the President to have "planned, authorized, committed, or aided the terrorist attacks" or "harboredsuch organizations or persons." Under this view, the United States is under actual and continuingenemy attack, and Congress delegated to the President the authority to declare those persons hedetermined to be subject to the AUMF to be wartime enemies. The U.S. military would beauthorized to use force to kill or capture persons it identifies as "enemy combatants," even withinthe United States. (243) However, those seeking a less expansive interpretation of the AUMF might argue that it must beread, if possible, to conform to international law and the Constitution. Under this view, for example,it might be questioned whether those sources of law provide adequate basis for a war against allegedmembers of a criminal organization and those who harbor them. (244) 

		Title 10, U.S.C

Before the Second Circuit, the government argued that Congress also authorized thedetention of enemy combatants in 10 U.S.C. Â§ 956(5), which authorizes the use of appropriatedfunds for "expenses incident to the maintenance, pay, and allowance of prisoners of war" as well as "other persons in the custody of the Army, Navy, or Air Force whose status is determined by theSecretary concerned to be similar to prisoners of war." The Administration interprets the phrase"similar to prisoners of war" to include "enemy combatants" who are not treated as prisoners of war.The Supreme Court plurality did not address this contention, having found the AUMF to provide thenecessary authority. The Second Circuit in Padilla rejected it based on its interpretation of Ex parteEndo requiring that language authorizing funds must "clearly" and "unmistakably" authorize thedetention of American citizens. (245) The government appears to have dropped the argument in theFourth Circuit, although that court found it persuasive. (246) 
It is not clear from the legislative history of 10 U.S.C. Â§ 956(5) that Congress accepted thenotion that there is a category of wartime detainees separate from prisoners of war and interned alienenemies. The language was first codified into title 10, U.S.C. in 1984, but has long been includedin appropriations bills for the Department of Defense. It first appeared in the Third SupplementalNational Defense Appropriation Act of 1942, (247) when the Army requested an addition to the defenseappropriations bill to provide the authority for the Secretary of War to 
utilize any appropriation available for the MilitaryEstablishment under such regulation as the Secretary of War may prescribe for all expenses incidentto the maintenance, pay and allowances of prisoners of war, other persons in Army custody whosestatus is determined by the Secretary of War to be similar to prisoners of war, and persons detainedin Army custody, pursuant to Presidential proclamation. (248)
It was explained that the expenses were in connection with keeping and maintaining prisonersof war and others in military custody not provided for by any appropriation; the example given wasthe construction of stockade authorized to be built in Honolulu and water supply for prisoners onOahu. (249) Thefollowing colloquy took place during Senate debate on the bill:
Mr. DANAHER. Mr. President, will the Senator fromTennessee permit me to invite his attention to page 9 of the bill before he starts on a newtitle?
Mr. McKELLAR. Certainly.
Mr. DANAHER. In lines 2 and 3 on page 9, we find thatthe committee has amended the bill to provide 'for all expenses incident to the maintenance, pay, andallowances of prisoners of war," and notably, "other persons in Army custody whose status isdetermined by the Secretary of War to be similar to prisoners of war." That is new language,apparently, and I should like to have the Senator explain what other class of persons there may bein Army custody whose status is similar to that of prisoners of war.
Mr. McKELLAR. Enemies who are found in thiscountry are taken up by the Army, and they have to be provided for. It was testified that at times itwas very necessary to arrest civilians and to provide for theircare.
Mr. DANAHER. I have not the slightest doubt that itis necessary, Is there existing law under which they are at present being taken up by theArmy?
Mr. McKELLAR. The Army did not want to take achance about it. 
Mr, DANAHER. Is there an existing law under whichsuch persons are today being taken up by the Army and being held asprisoners?
Mr. McKELLAR. The advice to the Committee was thatthere is not, and in order to make it absolutely sure the committee thought there should be such a provision, and this provision was inserted. I am quite sure the Senator will, under the circumstances,agree that it should be included in the bill.
Mr. DANAHER. I have not the slightest question thatit is absolutely necessary that certain classes of persons be taken up, not allowed to roam at large toour detriment. There is no question as to that. All I wish to know is where authority to do that isfound in the law. Is their status defined? Under what circumstances may they be taken up? If therebe no such authority anywhere, then I think we should very promptly and properly direct ourattention to such a field. We certainly are not going to authorize it merely by providing in anappropriation bill for an allotment of money to be paid after they are taken up.
Mr. McKELLAR. The Senator misunderstands me. Theappropriation is not to pay for their being taken up, but it is to maintain them and to keep them safelyafter they are taken up by whatever authority, that this appropriation isrecommended.
Mr. DANAHER. The Senator feels he is quite correctin saying that up to now there is no authorization provided by statute for their being taken up by the Army?
Mr. McKELLAR. There is no authorization for takingcare of them and feeding them and imprisoning them, and no place to imprison them, as Iunderstand. 
Mr. DANAHER. I thank the Senator. (250)
Prior to the amendment coming up for a vote, Senator Danaher took the occasion to look up whichsections of law provided authority for the Army to detain persons, and concluded the authority wasto be found in the Alien Enemy Act, 50 U.S.C. Â§ 21, which he read into the Record in its entirety andexplained:
I understand that since the first of the week the Presidenthas in fact issued proclamations under the authority of the section just quoted, and that so much ofthis section as applies to prisoners of war and those whom the Secretary of War may deem to besimilar in status to prisoners of war, is comprehended within the terms of the proclamations that areapplicable outside the immediate territorial limits of the United States. In view of the fact that thatimportant section does implement both the statute and the proclamations issued pursuant thereto, Ifeel that it is important that the Record should show what the situation is. (251)
The amendment was agreed to. Similar language has appeared in subsequent defenseappropriations until 1983, when it was added to title 10 as a note to section 138, (252) and then codified in1984 in its present form. (253) The Senate debate did not question the President's authorityto detain prisoners of war, despite the absence of express statutory authority, but only questioned themeaning of "other persons similar to prisoners of war." The legislative history could be interpretedto demonstrate that the language was meant only to pay for the exercise of authority found elsewhere,in particular the provisions of 50 U.S.C. Â§ 21. It is unlikely that 10 U.S.C. Â§956(5) would beinterpreted as amending 50 U.S.C. Â§ 21 with respect to the requirement for a declared war orPresidential proclamation. As an appropriations measure, it probably could not be interpreted toauthorize by implication what Congress has not provided for elsewhere, nor is it likely that thelanguage would be interpreted to repeal by implication express language contradicting theinterpretation. 
Legislation regarding prisoners of war and enemy aliens subsequent to the DefenseAuthorization Act arguably supports the understanding that, at least on the territory of the UnitedStates, Congress did not contemplate that any persons would be interned in any status other than thatof prisoner of war or enemy alien. In 1945, at the request of the Attorney General Biddle, Congressenacted a provision making it a criminal offense to procure or aid in the escape of persons internedas prisoners of war or alien enemies. (254) The provision was recommended to fill a gap in the law,which provided for the punishment of persons who procure or aid the escape of prisoners properlyin the custody of the Attorney General or confined in any penal or correctional institution. (255) 

		18 U.S.C. Â§ 4001(a)

The petitioners in both Hamdi and Padilla asserted that Congress expressly has forbiddenthe detention of U.S. citizens without statutory authority, and that no statutory support for thedetention of U.S. citizens as "enemy combatants" can be found. They cite 18 U.S.C. Â§ 4001(a),which provides:
No citizen shall be imprisoned or otherwise detainedby the United States except pursuant to an Act of Congress.
This language originated with the repeal of the Emergency Detention Act (256) in 1971. The legislativehistory demonstrates that Congress intended to prevent recurrence of internments in detention campssuch as those that had occurred during the Second World War with respect toJapanese-Americans. (257) The language "imprisoned or otherwise detained" in 18 U.S.C.Â§ 4001(a) has been construed literally by the Supreme Court to proscribe "detention of any kind bythe United States absent a congressional grant of authority to detain." (258) The four Justices ofthe Hamdi plurality and presumably Justice Thomas in his dissent agreed that it does not prohibitdetention pursuant to the law of war. Justices Souter and Ginsburg agreed with that as a generalprinciple, but would not have applied it to Hamdi because they argued that the government was notfollowing the customary law of war with respect to persons captured in Afghanistan. JusticesStevens and Scalia, in dissent, would have found the AUMF insufficiently clear to override theprohibition. (259) 
Petitioners for Padilla argue that the authorization found under the AUMF in Hamdi does notapply to Padilla's case. The Department of Justice takes the opposite view. Further, it notes that 18U.S.C. Â§ 4001(b) refers to federal penal and correctional institutions, except for military or navalinstitutions, and thus concludes that Â§ 4001(a) likewise refers only to federal penitentiaries. (260) The Fourth Circuitpreviously found in Hamdi III that Â§ 4001(a) was not intended to apply to enemy combatants, sincethere was no evidence in the legislative record that Congress had intended to "overturn thelong-standing rule that an armed and hostile American citizen captured on the battlefield duringwartime may be treated like the enemy combatant that he is." (261) The Fourth Circuitdistinguished the facts of Hamdi's case from those in Padilla's, however. (262) The District Court forthe District of South Carolina found, as the Second Circuit had, that Â§ 4001(a) does apply to U.S.prisoners in Padilla's situation. 

	The Role of Congress

Congress has ample authority under Article I of the Constitution to regulate the capture anddetention of enemy combatants. (263) One bill has been introduced in the 109th Congress, theDetention of Enemy Combatants Act, H.R. 1076 , that would assert congressionalauthority to limit the detention of U.S. persons as enemy combatants to defined circumstances, aswell as address some of the due process concerns that have been raised. While it appears thatexpress statutory authorization to detain persons arrested away from any battlefield would clarifyconstitutional separation of powers issues, some constitutional questions may remain. The SupremeCourt has never expressly upheld the administrative detention or internment of U.S. citizens andnon-alien enemies during war as a preventive measure. 

		The Proposed Detention of Enemy Combatants Act

The Detention of Enemy Combatants Act, H.R. 1076 , would assertcongressional authority to limit the detention of U.S. persons as enemy combatants to definedcircumstances and address some of the due process concerns that have been raised with respect tothe designation of enemy combatants. H.R. 1076 would authorize the President to detainU.S. citizens and residents who are determined to be "enemy combatants" in accordance withprocedures established by the Secretary of Defense in consultation with the Secretary of State andthe Attorney General. The bill would permit detainees to have access to attorneys to challenge thebasis for their detention, and would not suspend the writ of habeas corpus . The bill would not applyto combatants captured on a battlefield overseas or suspected criminals arrested abroad who are notU.S. citizens or residents.
Section-by-section Analysis.
Section 2. Findings. H.R. 1076 wouldfind that the United States and its allies are engaged in an armed conflict with Al Qaeda as justifiedunder international law for certain terrorist attacks. Paras. 1-6. The bill would take note of thedifficulties inherent in determining who is an enemy combatant in the context of the present war, butreaffirm the need to detain enemy combatants as appropriate "to protect the safety of the public andthose involved in the investigation and prosecution of terrorism, to facilitate the use of classifiedevidence without compromising intelligence or military efforts, to gather unimpeded vitalinformation from the detainee, and otherwise to protect national security interests." Para. 8-9. Further, the bill would find that the Executive must be allowed broad latitude to establish regulationsfor determining which U.S. citizens and residents may be detained, and that courts must give broaddeference to military judgment in such matters. Para. 10. It would verify that section 4001(a) of title18, U.S. Code "proscribes detention of any kind ... absent a congressional grant of authority todetain." Para. 11. The bill would find that Congress has authorized the President to detain U.S.persons "who are members of al Qaeda, or knowingly cooperated with members of al Qaeda in theplanning, authorizing, committing, aiding or abetting of one or more terrorist acts against the UnitedStates." Para. 12. The bill would find that constitutional protection does not cease during wartime,para. 13, and declare that it does not authorize the detention of U.S. persons as enemy combatants"indefinitely without charges and hold them incommunicado without a hearing and without accessto counsel on the basis of a unilateral determination that the person may be connected with anorganization that intends harm to the United States." Para. 14. It would reaffirm the right to habeascorpus, para. 15, and declare that Congress "has a responsibility for maintaining vigorous oversightof detention of [U.S. persons] to assure ... due process." Para. 16.
Section 3. Detention of Enemy Combatants. Section3 authorizes the detention of enemy combatants, which it defines as U.S. persons or residents "whoare members of Al Qaeda or knowingly cooperated with a member of al Qaeda in the planning,authorizing, committing, aiding or abetting of one or more terrorist acts against the United States,"but who are not entitled to prisoner-of-war status. The authority to establish the standards, process,and criteria to be used for the "enemy combatant" designation would be delegated to the Secretaryof Defense, in consultation with the Secretary of State and the Attorney General. It would notrequire different procedures depending on the circumstances of capture or arrest of the designee, but,assuming the act would apply extraterritorially, presumably the military would continue using rulesof engagement developed for a particular military operation to identify enemy combatants duringbattle, at least until it could be determined whether a captured person is a U.S. person.
Section 4. Procedural Requirements. The proceduralrules established under section 3 would be required to establish clear standards and procedures thatwould preserve the Government's ability to detain U.S. persons or residents who may threaten theUnited States or who might be able to furnish valuable intelligence. The rules would also berequired to contain procedures for the protection of classified information or information that, ifreleased, could impede the investigation of terrorism. Lastly, the rules would also have to providedetainees with timely access to judicial review (in the U.S. District Court for the District ofColumbia, according to sec. 5(b)) and access to counsel. 
Section 5. Detention. Section 5 would limit theduration of detention under the act to a period in which the President certifies that the war againstAl Qaeda is ongoing and that there is "an investigation with a view toward prosecution, aprosecution, or a post-trial proceeding" in the case of the detainee. Because it does not expresslylimit the latter requirement to proceedings before Article III courts, the condition might arguably besatisfied by trial by military commission or some other administrative tribunal. (264) The President wouldalso have to certify that detention is warranted to prevent the detainee "from aiding personsattempting to commit terrorist acts against the United States." The certification would have to berenewed after 180 days, with no limit on the number of successive certifications. Subsection (c)would authorize the Secretary of Defense to designate an appropriate location for the detentionsauthorized under the act, and would list minimal requirements for the condition of detention toensure humane treatment.
Section 6. Reports to Congress. Section 6 wouldrequire an annual report to Congress identifying each individual "subject to, or detained pursuant tothe authority of [the] Act." It is unclear who would be "subject to" the provisions of H.R. 1076 but not detained pursuant to them. Perhaps the phrase "subject to ... the Act"is meant to cover those who are detained within the regular criminal justice system or pursuant tothe authority of immigration laws, but who fit the criteria to be deemed enemy combatants. 
Section 7. United States Person or Resident Defined. Section 7 borrows the definition of "U.S. person" from section 101(i) of the Foreign IntelligenceSurveillance Act of 1978 (50 U.S.C. 1801(i)), which currently covers
a citizen of the United States, an alien lawfully admittedfor permanent residence (as defined in section 1101(a)(20) of title 8), an unincorporated associationa substantial number of members of which are citizens of the United States or aliens lawfullyadmitted for permanent residence, or a corporation which is incorporated in the United States, butdoes not include a corporation or an association which is a foreign power, as defined in subsection(a)(1), (2), or (3) of this section.
"Lawfully admitted for permanent residence" is defined under 8 U.S.C. Â§ 1101(a)(20) tomean "the status of having been lawfully accorded the privilege of residing permanently in theUnited States as an immigrant in accordance with the immigration laws, such status not havingchanged." Section 7 of H.R. 1076 also includes a separate subsection that defines "U.S.person or resident" to include "an alien lawfully admitted to the United States for permanentresidence." It is unclear whether this language is intended to cover a broader category of personsthan the definition already referenced in subsection (1). It appears that H.R. 1076 wouldnot reach aliens lawfully admitted to the United States on a temporary basis or who are awaiting finalapproval of their applications for permanent residence, nor would it reach aliens present in theUnited States unlawfully. This omission could be read either to imply that the President has theinherent authority under the Constitution to detain persons not covered under the definition in section7, or unless Congress has provided such authority elsewhere, it could be read to preclude thedetention of such persons as enemy combatants.
Section 8. Termination of Authority. Section 8 is asunset provision terminating the above authority as of December 31, 2007. The authority wouldeffectively terminate earlier if the armed conflict with Al Qaeda were to end prior to that date.

		Possible Legal Issues

Petitioners on behalf of U.S. citizens held in military custody argue that 18 U.S.C. Â§ 4001(a),which prohibits the detention of U.S. citizens except as authorized by an act of Congress, prohibitsthe military's detention of U.S. citizens as enemy combatants. While H.R. 1076 wouldappear to resolve the question of whether statutory law prohibits the detention of U.S. citizens asenemy combatants, it leaves open some legal questions pertaining to the detention of persons asenemy combatants that may arise under the Constitution and international law. 
Some Constitutional Questions. The SupremeCourt has never expressly upheld the administrative detention or internment of U.S. citizens andnon-alien enemies during war as a preventive measure. 
Congressional Authority. In Ex parte Milligan , (265) the Supreme Courtinvalidated a military detention and sentence of a civilian for violations of the law of war, despiteaccusations that Milligan conspired and committed hostile acts against the United States. (266) A plurality of the Milligan Court agreed that Congress was not empowered to authorize the President to assert militaryjurisdiction in areas not subject to martial law, but scholars disagree as to whether that portion of theopinion is binding as law or is merely dicta . The Administration may take the view that only thePresident, and not Congress, has the constitutional authority to detain enemy combatants, but itappears from the historical survey above that the contention lacks any solid legal precedent. 
The Korematsu (267) decision is frequently cited as upholding the internment ofJapanese-Americans during World War II, but the Supreme Court expressly limited its decision tothe legality of excluding these citizens from declared military areas. Ex parte Endo (268) invalidated thedetention of a U.S. citizen who was "concededly loyal" to the United States, possibly implying thatthe detention of disloyal citizens may be permissible under some circumstances, but leaving openthe question of what constitutional due process is required to determine the loyalty of persons thegovernment sought to intern. In 1950, Congress passed the Emergency Detention Act (EDA), (269) which authorized thePresident to declare an "Internal Security Emergency," during which the President could authorizethe apprehension and detention of any person deemed reasonably likely to engage in acts ofespionage or sabotage. However, this authority was never exercised, and the EDA was repealedwithout any court having had the opportunity to evaluate its constitutionality. (270) H.R. 1076 would guarantee access to counsel and the right to challenge detention by petitioning for a writ ofhabeas corpus, but gives the executive little other guidance as to what due process the act requires. 
Bill of Attainder. H.R. 1076 may besubject to criticism for possibly violating the constitutional prohibition of bills of attainder. (271) The Constitutionprohibits Congress from enacting legislation to punish specific persons or easily identifiable groupsof persons. (272) Section 3 of H.R. 1076 would authorize the President to detain persons based on theirmembership in Al Qaeda or knowing cooperation with a member of Al Qaeda. Although the statedpurpose for the detention appears to be preventive rather than punitive, the nature of the restraint andthe requirement that non-members of Al Qaeda act "knowingly" probably make it punitive for thepurpose of finding a bill of attainder. (273) However, section 5 would require a certification that there is"an ongoing investigation with a view toward prosecution, a prosecution, or a post-trial proceeding"and that the detention is warranted to prevent the person from contributing to terrorist acts againstthe United States. The requirement for an individualized finding of dangerousness would likelydefeat any challenges that the act amounts to a legislative determination of guilt. (274) 
Ex Post Facto Law. Similarly, H.R. 1076 could be subject to challenge as an impermissible ex post facto law. (275) Every law that makescriminal an act that was innocent at the time it was committed, or that increases the punishment toa crime already committed, is an ex post facto law prohibited by the Constitution. (276) The prohibition doesnot apply to laws of a non-criminal or non-punitive nature, (277) but cannot be evadedby clothing a punitive law in civil guise. (278) If a U.S. person were detained pursuant to the Detention ofEnemy Combatants Act for past membership in Al Qaeda, for example, or for cooperation withterrorists that took place prior to the enactment of the act, such detainee might challenge the act asimposing new burdens for past conduct, in violation of the Ex Post Facto Clause of the Constitution. However, detention under the act could continue only for so long as "an investigation with a viewtoward prosecution, a prosecution, or a post-trial proceeding" with respect to a particular detaineewere ongoing, and only if the President certifies that detention is warranted to prevent further actsof terrorism, in which case detention could be permissible under ordinary penal statutes. The legalityof the detention will likely depend on the extent to which the procedures put in place by theexecutive satisfy the constitutional requirements for a temporary deprivation of liberty.
Due Process for Non-Resident Aliens. H.R. 1076 does not apply to non-resident aliens and other non-citizens not lawfullyadmitted for permanent residence in the United States. Although Hamdi may be read to apply dueprocess rights only in the case of U.S. citizens, legislation that applies in a different way tonon-resident aliens, for example without mandating any sort of hearing at all, may raiseconstitutional issues. Aliens in the United States, whatever their immigration status, are "persons"whose liberty interests are protected by the Fifth Amendment. (279) While the standardsfor administrative decisions relating to immigration status are not as extensive as due processrequirements for criminal procedures, other types of proceedings do not treat aliens as having fewerrights under the Constitution. Of course, the existence of a state of war might work as an exceptionto this general rule. During a declared war, enemy aliens are by statute subject to detention anddeportation based on their nationality, (280) in accordance with procedures set up by the executive branch. The Supreme Court validated such a program during World War II. (281) It may thus bepermissible for Congress, in the exercise of its war powers, to enact specific legislation defining whomay be interned as an enemy based on factors other than nationality, but it is not clear that thePresident has the authority to intern persons as enemies without specific authorization fromCongress. If non-permanent resident aliens are intended to be subject to detention as enemycombatants, it may be advisable to include them under the same authority that applies to citizens andaliens lawfully admitted for permanent residence in the United States.
International Legal Issues. Because the detentionof enemy combatants is a means of conducting war, it is subject to the international law of war. (282) H.R. 1076would not authorize the detention of enemy combatants who are entitled to prisoner of war statusunder the Third Geneva Convention, (283) but it could be read to authorize the detention of civilianpersons protected by the Fourth Geneva Convention (284) under conditions that do not meet the requirements of thattreaty. It is not clear whether the 1949 Geneva Conventions apply in their entirety during the waragainst terrorism as they would in the case of an international war, or whether the war should becategorized as an "armed conflict not of an international character occurring in the territory of oneof the High Contracting Parties," in which case only common article 3 of the Geneva Conventionswould apply. (285) H.R. 1076 may satisfy U.S. obligations under common article 3. 
H.R. 1076 may come under criticism for failing to define "enemy combatant" as that termis ordinarily understood in the context of the law of war. As a general rule, combatants are soldiersand others who engage in combat. Combatants are lawful military targets during combat operations,but the law of war prefers capture and detention as a more humane alternative to killing or woundingthem. Aiders and abettors of the enemy (and terrorists) traditionally have been treated as criminalcivilians rather than enemy combatants, and are not ordinarily treated as lawful military targetsexcept perhaps in the extreme circumstances where the use of deadly force would be warrantedagainst a person committing or about to commit a hostile act. (286) The use of the phrase"enemy combatant" to describe both battlefield combatants and criminals arrested in areas where lawand order appear to prevail suggests that the use of military force is authorized as if a global battlewere taking place. 

	Conclusion

It appears likely that the Supreme Court has not issued its last word on "enemy combatants"and executive detention as a means to prosecute the war on terrorism. (287) Lower courts that haveaddressed questions the Supreme Court left unanswered have not achieved a consensus, althoughit appears that the trend does not favor the expansive view of executive power urged by thegovernment. As a consequence, the extent to which the Congress has authorized the detentionwithout trial of American citizens as "enemy combatants" will likely remain an important issue fordetermining the validity of the Administration's tactics. While the broad language of theAuthorization for the Use of Military Force ("AUMF") (288) authorizes the use of such military force as the President deemsappropriate in order to prevent future acts of terrorism, it remains possible to argue that the AUMFwas not intended to authorize the President to assert all of the war powers usually reserved forformal declarations of war. (289) 
History shows that even during declared wars, additional statutory authority has been seenas necessary to validate the detention of citizens not members of any armed forces. Courts, however,have not explicitly ruled on the point with respect to circumstances like these. Congressional activitysince the Quirin decision suggests that Congress did not interpret Quirin as a significant departurefrom prior practice with regard to restriction of civil liberties during war. If that is the case, it maybe that Congress intended to authorize the capture and detention of individuals like Hamdi --persons captured on the battlefield during actual hostilities -- for so long as military operationsremain necessary, while withholding the authority to detain individuals like Padilla -- an accusedenemy agent operating domestically -- except in accordance with regular due process of law. IfCongress were to pass legislation authorizing the detention of persons as enemy combatants, futuredetentions would likely face fewer hurdles in court. (290) However, even with the express authorization of Congress,constitutional due process issues seem likely to arise.

Summary:
The Supreme Court in 2004 issued three decisions related to the detention of "enemycombatants," including two that deal with U.S. citizens in military custody on American soil. In Hamdi v. Rumsfeld , a plurality held that a U.S. citizen allegedly captured during combat inAfghanistan and incarcerated at a Navy brig in South Carolina is entitled to notice and anopportunity to be heard by a neutral decision-maker regarding the government's reasons for detaininghim. The Court in Rumsfeld v. Padilla overturned a lower court's grant of habeas corpus to anotherU.S. citizen in military custody in South Carolina on jurisdictional grounds. The decisions affirmthe President's powers to detain "enemy combatants,"including those who are U.S. citizens, as partof the necessary force authorized by Congress after the terrorist attacks of September 11, 2001. However the Court appears to have limited the scope of individuals who may be treated as enemycombatants pursuant to that authority, and clarified that such detainees have some due process rightsunder the U.S. Constitution. This report, which will be updated as necessary, analyzes the authorityto detain American citizens who are suspected of being members, agents, or associates of Al Qaeda,the Taliban and possibly other terrorist organizations as "enemy combatants."
The Department of Justice argues that the recent decisions, coupled with two World War IIera cases, Ex parte Quirin and In re Territo , support its contention that the President may order thatcertain U.S. citizens as well as non-citizens be held as enemy combatants pursuant to the law of warand Article II of the Constitution. Critics, however, question whether the decisions permit thedetention of U.S. citizens captured away from any actual battlefield, in order to prevent terrorist actsor gather intelligence; and some argue that Congress has prohibited such detention of U.S. citizenswhen it enacted 18 U.S.C. Â§ 4001(a).
This report provides background information regarding the cases of two U.S. citizens deemed "enemy combatants," Yaser Esam Hamdi, who has been returned to Saudi Arabia, and JosePadilla, who remains in military custody while the government appeals a district court order tocharge him with a crime or release him. A brief introduction to the law of war pertinent to thedetention of different categories of individuals is offered, followed by brief analyses of the mainlegal precedents invoked to support the President's actions, as well as Ex parte Milligan , which someargue supports the opposite conclusion. A discussion of U.S. practice during wartime to detainpersons deemed dangerous to the national security follows, including legislative history that mayhelp to shed light on Congress' intent in authorizing the use of force to fight terrorism. Finally, thereport briefly analyzes the proposed Detention of Enemy Combatants Act, H.R. 1076 ,which would authorize the President to detain U.S. citizens and residents who are determined to be"enemy combatants" in certain circumstances. The report concludes that historically, even duringdeclared wars, additional statutory authority has been seen as necessary to validate the detention ofcitizens not members of any armed forces, casting in some doubt the argument that the power todetain persons arrested in a context other than actual hostilities is necessarily implied by anauthorization to use force.