Enemy Combatant: A Genealogy

As we’ve discussed, the term “enemy combatant”—whether lawful or unlawful—is not a term of art in international humanitarian law (IHL). Until it was recently retired by the Obama Administration, however, the term had been a key feature of the “War on Terror" lexicon. With the expert assistance of my ace research assistant, Rockford Hearn (right), I have been constructing a genealogy of the term in light of its linguistic demise. Since its inception, the definition of "enemy combatant" has seen significant evolution with respect to its two constitutive parts:

1. enemy &
2. combatant.

1. Ex Parte Quirin

Although of modern relevance, the term traces its roots to the U.S. Supreme Court’s opinion in the infamous WWII German saboteurs case. Ex Parte Quirin, 317 U.S. 1 (1942). This case concerned eight individuals, one a citizen of the U.S., who exited German subs and came ashore in civilian clothes intent on engaging in acts of sabotage. (The case's namesake is at left). On their petition for a writ of habeas corpus, the Supreme Court identified a category of belligerent who was not entitled to prisoner of war (POW) treatment:

[t]he spy who secretly and without uniform passes the military lines of a belligerent in time of war, seeing to gather military information and communicate it to the enemy, or an enemy combatant who without uniform comes secretly through the lines for the purpose of waging war by destruction of life or property [would exemplify] belligerents who are generally deemed not to be entitled to the status of prisoner of war, but to be offenders against the law of war subject to trial and punishment by military tribunals (p. 31).

After the FBI caught the saboteurs, the president issued a proclamation stating:

All persons who are subjects, citizens or residents of any nation at war with the United States or who give obedience to or act under the direction of any such nation, and who during time of war enter or attempt to enter the United States through coastal or boundary defenses, and are charged with committing or attempting or preparing to commit sabotage, espionage, hostile or warlike acts, or violations of the law of war, shall be subject to the law of war and to the jurisdiction of military tribunals (pp. 22-23).

The men were charged and transferred into military custody for prosecution before a military commission. In denying their petition for a writ of habeas corpus, the Supreme Court distinguished between lawful and unlawful combatants, noting that while lawful combatants are to be classified as POWs, and are subject to capture and detention, unlawful combatants are additionally “subject to trial and punishment by military tribunals for acts which render their belligerency unlawful” (p. 31). The Court used several monikers in referring to the petitioners (including “unlawful combatants,” “enemy belligerents,” and “enemy combatants”), implying that it was not employing these terms in any technical sense. Indeed, the Court cautioned that

[w]e have no occasion now to define with meticulous care the ultimate boundaries of the jurisdiction of military tribunals to try persons according to the law of war (pp. 45-46).

The petitioners were executed after the decision was announced but before the Court released its opinion.

2. 2001 Military Order

Fast forward to the immediate aftermath of the attacks of September 11th and President Bush’s Military Order of November 13, 2001. This Order authorized the detention of any non-citizen whom the President determined there was reason to believe:

1. is or was a member of the organization known as al Qaeda;
2. has engaged in, aided or abetted, or conspired to commit, acts of international terrorism, or acts in preparation therefore, that have caused, threaten to cause, or have as their aim to cause, injury to or adverse effects on the United States, its citizens, national security, foreign policy, or economy; or
3. has knowingly harbored one or more individuals described [elsewhere in] this order.

This definition focuses on three categories of person:

• members of al Qaida,
• those who committed acts of international terrorism aimed at, or adversely effecting, the United States (including by aiding, abetting, conspiring, or preparing), and
• those who harbored individuals so engaged.

This definition is notable in that it does not presume the existence of any armed conflict or act of belligerency; rather, it is premised on the commission of acts of international terrorism or al Qaida (as opposed to Taliban) membership. The definition reveals two alternative criteria: membership and participation in acts of terrorism (including harboring).

3. Hamdi v. Rumsfeld

In Hamdi v. Rumsfeld, 542 U.S. 507 (2004), the Court again had occasion to consider this concept. In a June 28, 2004 decision, a plurality of the Court adopted for the purpose of the case the definition suggested by the Bush Administration:

An enemy combatant is an individual who was
1. Part of or supporting forces hostile to the U.S. or coalition partners in Afghanistan and

2. Who engaged in an armed conflict against the U.S. there (p. 516).

Recognizing, however, that the proper scope of the term “enemy combatant” was unsettled, the Court left the task of delineating its “permissible bounds” to the lower courts (p. 522).

The working definition in Hamdi first introduced the idea that individuals who were not part of a fighting force or organization may be considered enemy combatants if they nonetheless “supported” the group. It also suggested that the individual must “engage[] in armed conflict” against the United States in Afghanistan. This would imply that someone who was a part of the Taliban but left that group prior to the United States invasion in October 2001 would not qualify as an enemy combatant, because that person was never opposed to the U.S. or its coalition partners. This definition also is in the conjunctive: both membership and participation (this time in armed conflict rather than terrorism) are required.

4. Combatant Status Review Tribunal Definition

A mere two weeks later, the U.S. Navy promulgated a new enemy combatant definition in a July 7, 2004 memorandum to then Deputy Secretary of Defense Paul Wolfowitz (Memorandum from Deputy Sec’y of Defense Paul Wolfowitz to the Sec’y of the Navy, Order Establishing Combatant Status Review Tribunal (July 7, 2004)). The Memorandum provided that the term "enemy combatant" would henceforth mean:

1. an individual who was part of or supporting Taliban or al Qaida forces, or associated forces that are engaged in hostilities against the U.S. or its coalition partners.
2. This includes any person who has committed a belligerent act or has directly supported hostilities in aid of enemy armed forces.

This definition was subsequently incorporated into the rules utilized by the Combatant Status Review Tribunals (CSRTs) to determine whether individuals on Guantánamo were properly designated and detainable. The Navy/CSRT definition introduced the idea of “associated forces” beyond the Taliban or al Qaida. It also maintained the support element. The definition hinges more directly on mere membership and implies that even individuals who have not committed a belligerent act or directly supported hostilities would qualify for detention.

5. Military Commission Act (defining "Lawful" and "Unlawful" Enemy Combatants)

The Military Commission Act of 2006 (promulgated October 17, 2006) adapted this definition somewhat to identify a category of unlawful enemy combatants who would fall within military commission jurisdiction. By contrast, the Act provided that individuals who were deemed to be lawful enemy combatants could not be tried by military commission.

1. UNLAWFUL ENEMY COMBATANT
A. The term ‘unlawful enemy combatant’ means:
(i) a person who has engaged in hostilities or who has purposefully and materially supported hostilities against the United States or its co-belligerents who is not a lawful enemy combatant (including a person who is part of the Taliban, al Qaeda, or associated forces); or
(ii) a person who, before, on, or after the date of the enactment of the Military Commissions Act of 2006, has been determined to be an unlawful enemy combatant by a Combatant Status Review Tribunal or another competent tribunal established under the authority of the President or the Secretary of Defense. ...

2. LAWFUL ENEMY COMBATANT
A. The term ‘lawful enemy combatant’ means a person who is
(i) a member of the regular forces of a State party engaged in hostilities against the United States;
(ii) a member of a militia, volunteer corps, or organized resistance movement belonging to a State party engaged in such hostilities, which are under responsible command, wear a fixed distinctive sign recognizable at a distance, carry their arms
openly, and abide by the law of war; or
(iii) a member of a regular armed force who professes allegiance to a government engaged in such hostilities, but not recognized by the United States (§ 948a).

A lawful enemy combatant is defined by way of membership criteria in accordance with the provisions set forth for prisoner-of-war classification scheme in Article 4 of the Third Geneva Convention. An unlawful enemy combatant, by contrast, is defined in terms of conduct—the participation in hostilities or the support of hostilities against the U.S.

In Boumediene v. Bush, 128 S.Ct. 2229 (decided June 12, 2008), the Court declined to address “[t]he extent of the showing required of the Government in these cases” (p. 2271). It noted: “[i]t bears repeating that our opinion does not address the content of the law that governs petitioners' detention. That is a matter yet to be determined” (p. 2277).

6. Al Marri v. Pucciarelli

The 4th Circuit in Al Marri v. Pucciarelli, 534 F. 3d 213 (decided July 15, 2008) also took a stab at defining the concept. Al Marri (petitioner at right), however, produced a fractured opinion that did little to clarify the definition. Judge Motz (left) joined by three colleagues relied on Hamdi and law of armed conflict principles to focus on the affiliation factor:

Enemy combatant status rests on an individual’s affiliation during wartime with the ‘military arm of the enemy government’ (p. 230).


According to this definition, al-Marri did not qualify as an enemy combatant because he did not affiliate ‘”with the armed forces of an enemy nation” (p. 230). Motz concluded that an individual may not be classified as an enemy combatant merely for engaging in criminal conduct.

By contrast, Judge Wilkinson (right), concurring in part and dissenting in part, adopted a different definition and reasoned that an enemy combatant is:

1. A member of
2. An organization or nation against whom Congress has declared war or authorized the use of military force, who
3. Knowingly plans or engages in conduct that harms or aims to harm persons or property for the purpose of furthering the military goals of an enemy nation or organization (p. 322).

In support of this definition, Wilkinson argued that the conception of “enemy” is no longer based on an individual’s nationality, because stateless actors (e.g., terrorist organizations) now pose the most compelling military threat to the U.S. In his estimation, membership in such an organization is functionally equivalent to traditional criteria of enemy status—an individual’s residency in, or citizenship of, an enemy nation. Indicia of membership may include:

• self-identification with the organization through verbal or written statements;
• participation in the group's hierarchy or command structure; or
• knowingly taking overt steps to aid or participate in the organization's activities.

In Wilkinson's view, these indicia distinguish those who are the enemy from those who merely sympathize with the enemy (p. 323).

The third criterion addresses who constitutes a “combatant,” distinguishing those with military aims from those who do not present a threat to opposing forces. Those who use military-like force against American soldiers or civilians obviously qualify as combatants under this formulation. Similarly, members of an “enemy sleeper terrorist cell” who have taken steps, even if preliminary in nature, toward a destructive act may also be considered combatants. Conversely, members of the enemy organization who do not intend hostile acts (such as an al Qaida physician) are non-combatants and are not subject to military jurisdiction. (More material on al-Marri is available here, the Brennan Center for Justice at NYU Law School.)

7. District Courts

Many district courts hearing habeas petitions in the wake of the Supreme Court’s decision in Boumediene adopted the Wolfowitz definition. On remand in that case, Boumediene v. Bush, 583 F.Supp.2d 133, 135 (D.D.C. Oct. 27, 2008), Judge Leon adopted the CSRT definition. Other courts called for additional briefing on this question. For a discussion of these cases, see here.

Eventually, as IntLawGrrls founder Diane Marie Amann has posted, the Obama administration abandoned the term "enemy combatant," but not the idea that certain individuals may be detained absent proof of the commission of any prosecutable crime. The new operative standard for detention contains a minor change to the standard employed in the CSRTs by raising the threshold of support to “substantial.”

The President has the authority to detain persons that the President determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, and persons who harbored those responsible for those attacks.

The President also has the authority to detain persons who were part of, or substantially supported, Taliban or al-Qaida forces or associated forces that
are engaged in hostilities against the United States or its coalition partners, including any person who has committed a belligerent act, or has directly supported hostilities, in aid of such enemy armed forces.

The brief made clear that this standard will be subject to further refinement:

the contours of the ‘substantial support’ and ‘associated forces’ bases of detention will need to be further developed in their application to concrete facts in individual cases.

Using basic principles of statutory interpretation, the definition at present seems to encompass several distinct categories of individual who did certain things, were members of certain groups, or substantially supported these groups. These are:

1. persons who were involved in (along a spectrum of planning, authorizing, committing, or aiding) the attacks of 9/11;
2. persons who harbored individuals “responsible” for the 9/11 attacks;
3. persons who were part of Taliban or al Qaida forces;
4. persons who were part of associated forces that are engaged in hostilities against the U.S. or its coalition partners;
5. persons who substantially supported Taliban or al Qaida forces;
6. persons who substantially supported associated forces that are engaged in hostilities against the U.S. or its coalition partners;
7. persons who committed a belligerent act in aid of “such enemy forces” (presumably the Taliban, al Qaida or “associated forces”);
8. persons who “directly supported” hostilities in aid of “such enemy forces” (presumably the Taliban, al Qaida or “associated forces”).

It is not entirely clear to what extent the addition of the “substantial” modifier might have generated different outcomes in the habeas cases already decided had the new Obama standard been operative. Certainly cases premised on guest house stays or the provision of non-combat support (such as cooking) might have come out differently. It remains to be seen to what extent the courts are willing to accept this new standard or even whether the Obama administration will continue to advance it in the face of significant criticism that it does not go far enough toward bringing the U.S. detention practice into line with international law.