Order Code RS21056
Updated November 28, 2001
CRS Report for Congress
Received through the CRS Web
Trying Terrorists as War Criminals
American Law Division
On November 13, 2001, President Bush signed a Military Order pertaining to the
detention, treatment, and trial of certain non-citizens in the war against terrorism. The
President’s Military Order makes it apparent that he plans to treat the attacks as acts of
war rather than criminal acts, and to prosecute those responsible as war criminals, trying
them by special military commission rather than in federal court. The purpose of this
report is to clarify the legal basis for treating the acts as war crimes and the ramifications
of applying the law of war rather than criminal statutes to prosecute the perpetrators.
The discussion focuses on the trial of alleged terrorists and conspirators by a military
commission rather than the federal courts. A longer treatment of the issues in this report
and an analysis of other relevant issues, including the Military Order, are contained in
CRS Report RL 31191.
In the aftermath of the September 11 terrorist attacks on the World Trade Center and
the Pentagon, the question of whether to treat the attacks as acts of war or criminal acts
has not been fully settled. The distinction may have more than rhetorical value. The
purpose of this report is to clarify the law enforcement implications of treating the terrorist
acts as war crimes and to identify the possible ramifications of applying the law of war
rather than criminal statutes to prosecute the alleged perpetrators.
Law Enforcement versus Law of War. Some observers have expressed
concern that treating terrorist acts as acts of war may legitimize the acts as a lawful use
of force and elevate the status of the Taliban and the terrorist networks to that of
legitimate state actors and lawful combatants. However, it may be argued that an
application of the law of war to terrorism does not imply lawfulness of the conflict, nor
does it imply that perpetrators are not criminals.1 Terrorists do not, by definition, conduct
themselves as lawful combatants.2 Under this view, they may be treated as war criminals
See LT. COL. RICHARD J. ERICKSON, LEGITIMATE USE OF MILITARY FORCE AGAINST STATESPONSORED INTERNATIONAL TERRORISM 63-65 (1989).
See Spencer J. Crona and Niel A. Richardson, Justice for War Criminals of Invisible Armies:
Congressional Research Service ˜ The Library of Congress
and if captured, are not entitled to prisoner-of-war status under the Geneva Conventions.
As suspected war criminals, they may be tried by any nation in its national courts or by a
military commission convened by one nation or many.
It appears that there are few legal impediments to adopting such an approach as to
enemy belligerents who allegedly violate the law of war, especially those captured
overseas.3 The right of the Commander in Chief to try war criminals in occupied territory
is well settled. Determining who qualifies as an “enemy belligerent” for acts committed
on U.S. territory, however, would likely present greater constitutional difficulties.4 Other
practical considerations that may arise include the following questions: Must war crimes
be investigated by military police, possibly implicating the Posse Comitatus Act? If federal
or state police are used, must they follow the same standards that they apply to criminal
cases? How will it affect the United States’ ability to extradite terrorists captured abroad?
Such an approach could also have an impact on civil matters. Will there be any effect
on the possible civil liability of terrorists to compensate victims?5 Would it matter if a
particular victim was a government employee or someone located at a “military target” at
the time of an attack? Will there be an effect on the liability of insurers?6 A decision to
adopt a law of war approach to the terrorist acts currently at issue, or to all future terrorist
acts, could also have significant foreign policy repercussions.
What is the Law of War? As a subset of the law of nations, the law of war is a
composite of many sources and is subject to varying interpretations constantly adjusting
to address new technology and the changing nature of war. It may also be referred to as
jus in bello, or law in war, which refers to the conduct of combatants in armed conflict,
as distinguished from jus ad bellum– law before war – which outlines acceptable reasons
for nations to engage in armed conflict.7 The main thrust of its principles requires that a
military objective be pursued in such a way as to avoid needless and disproportionate
suffering and damages. Sources of the law of war include international agreements,
customary principles and rules of international law, judicial decisions by both national and
A New Legal and Military Approach to Terrorism, 21 OKLA. CITY U.L. REV. 349 (1996).
Military jurisdiction in occupied areas is well established, even for ordinary crimes, as a power
necessary for military government. See In Re Yamashita, 327 U.S. 1 (1946). The commander also
has the option of detaining offenders until they can be delivered to civil authorities for trial. See
Gallagher v. United States, 423 F.2d 1371 (Ct. Cl. 1970).
See Ex Parte Milligan, 71 U.S. (4 Wall.) 2 (1866) (granting writ of habeas corpus to civilian
convicted by military commission for criminal offense where federal courts were available).
Civil actions brought under 18 U.S.C. §2333 (terrorism remedies) may not be maintained for acts
of war. 18 U.S.C. §2335. Defendants convicted under criminal proceedings are estopped from
denying responsibility in any subsequent civil suit. 18 U.S.C. §2333(b). Under current law, it is
unclear whether a conviction by military commission could be invoked in this way.
See Insurance Exclusion Clauses and Coverage of the Events of September 11, CRS Report
RL31166 (Oct. 20, 2001).
See DOCUMENTS ON THE LAWS OF WAR 2 (Adam Roberts and Richard Guellf, eds. 2000).
international tribunals, national manuals of military law, treatises, and resolutions of
various international bodies.8
At the risk of oversimplifying the concept, three principles derived from the law of
war may be applied to assess the legality of any use of force for political objectives.9
Military necessity. If the use of force is justified, that use must be proportional
in relation to the anticipated military advantage or as a measure of self-defense. The
principle applies to the choice of targets, weapons and methods. This principle, however,
does not apply to unlawful acts of war. There can be no excuse of necessity if the resort
to the use of arms is not itself justified.
Humanity. Lawful combatants are bound to use force discriminately. In other
words, they must limit targets to valid military objectives and must use means no harsher
than necessary to achieve that objective. They may not use methods designed to inflict
needless suffering, and they may not target civilians.
Chivalry. Combatants must adhere to the law of armed conflict in order to be
treated as lawful combatants. They must respect the rights of prisoners of war and
captured civilians, and avoid behavior such as looting and pillaging. They may not
disguise themselves as non-combatants.
Although these principles leave a great deal of room for interpretation, there can be
little doubt, assuming such acts can be viewed as acts of war, that the attacks of
September 11 were not conducted in accordance with the law of war. Even if one
considers the Pentagon to be a valid military target, the hijacking of a commercial airliner
is not a lawful means for attacking it.
Constitutional Bases for Establishing Military Commission. The
Constitution empowers the Congress to define and punish violations of international law10
as well as to establish courts with exclusive jurisdiction over military offenses.11 United
States law recognizes the legality of creating military commissions to deal with “offenders
or offenses designated by statute or the law of war.”12 Under the former Articles of War
and subsequent statute,13 the President has authority to convene military commissions to
See id. at 4.
See id. at 9.
U.S. CONST. art. I, § 8, cl. 10.
Id. art. I, § 8, cl. 14.
10 U.S.C. § 821. Statutory offenses for which a military commission may be convened include
only aiding the enemy, 10 U.S.C. § 904, and spying, 10 U.S.C. § 906.
The Articles of War were codified at 10 U.S.C. § 801 et seq. as part of the Uniform Code of
Military Justice (UCMJ). Although the cases cited in this report interpret the Articles of War, the
relevant sections of the UCMJ would likely be interpreted to be essentially identical. See Robinson
O. Everett & Scott L. Silliman, Forums for Punishing Offenses Against the Law of Nations, 29
WAKE FOREST L. REV. 509, 515 (1994).
try offenses against the law of war.14 Military commissions could be convened to try such
offenses whether committed by U.S. servicemembers, civilian citizens, or enemy aliens.15
A declared state of war need not exist.16
Precedent. Although the current crisis does not fit the typical mold associated with
war crimes committed by otherwise lawful combatants in obvious theaters of war, there
is precedent for convening military commissions to try accused saboteurs for conspiring
to commit violations of the law of war outside of the recognized war zone. In the World
War II case of Ex Parte Quirin, eight German saboteurs (one of whom was purportedly
a U.S. citizen) were tried by military commission for entering the United States by
submarine, shedding their military uniforms, and conspiring to use explosives on unknown
targets. After their capture, President Roosevelt proclaimed that all saboteurs caught in
the United States would be tried by military commission. The Supreme Court denied their
writs of habeas corpus, holding that trial by such a commission did not offend the
Power of the Military Commission. As a non-Article III court, a military
commission is not subject to the same constitutional requirements that apply to Article III
courts.17 Defendants properly before a military commission, like defendants before a courtmartial, have no right to demand a jury trial18 before a court established in accordance with
rules governing the judiciary.19 There is no right of indictment or presentment under the
Fifth Amendment,20 and there may be no protection against self-incrimination or right to
counsel.21 While Congress has enacted procedures applicable to courts-martial that ensure
basic due process rights,22 no such statutory procedures exist to codify due process rights
for defendants before military commissions.
Ex Parte Quirin, 317 U.S. 1 (1942).
Johnson v. Eisentrager, 339 U.S. 763, 786 (1950); cf Madsen v. Kinsella, 343 U.S. 341
(1952)(validating conviction by military commission of spouse of servicemember for crime
committed in occupied territory).
Johnson v. Eisentrager, 339 U.S. at 786 (citing Duncan v. Kahanamoku, 327 U.S. 304 (1945)).
See Crona and Richardson, supra note 2, at 360-61.
Ex Parte Quirin, 317 U.S. 38; see also Granfinanciera, S.A. v. Nordberg, 492 U.S. 33, 53-54
(1989); Audrey I. Benison, International Criminal Tribunals: Is There a Substantive Limitation
on the Treaty Power?, 37 STAN. J INT'L L. 75, 99 (2001). The same is true for a military courtmartial conducted under the Uniform Code of Military Justice. Ex Parte Milligan, 71 U.S. (4
Wall.) 2, 123 (1866) (noting a servicemember “surrenders his right to be tried by the civil courts”).
Ex Parte Quirin, 317 U.S. 1, 45 (1942).
Weiss v. United States, 510 U.S. 163 (1994) (rejecting challenge to the military justice system
based on the fact that military judges are not “appointed” by the President within the meaning of
Article II of the Constitution, and the judges are not appointed to fixed terms of office).
See Ex Parte Milligan, 71 U.S. (4 Wall.) 2, 123 (1866).
Middendorf v. Henry, 425 U.S. 25 (1976) (holding there is no right to counsel under U.S. Const.
amends. V or VI in summary courts-martial).
Weiss at 178 (holding procedures established by Congress to govern military justice to be
adequate to ensure a fair trial consistent with the Due Process Clause of the Fifth Amendment).
Congress has delegated to the President the authority to convene military
commissions, set rules of procedure, and review their decisions. This authority may be
delegated to a field commander or any other commander with the power to convene a
general court-martial.23 Statutes authorize prosecuting persons for failure to appear as
witness,24 punishing contempt,25 and accepting into evidence certain depositions26 and
records of courts of inquiry.27
Procedural Rules. Procedural rules and evidentiary rules are prescribed by the
President and may differ among commissions.28 Courts-martial are conducted using the
Military Rules of Evidence set out in the Manual for Courts-Martial;29 however, these rules
need not apply to trials by military commission.30 Subject to the statutory provisions
above, the President may establish any rules of procedure and evidence he deems
Although there may be little judicial review available to persons convicted by U.S.
military commissions, it is surely necessary to provide for trials that will be fundamentally
fair under both U.S. and international standards regarding the application of the law of
war.31 Telford Taylor noted in evaluating World War II war crimes trials:
It is of the first importance that the task of planning and developing permanent judicial
machinery for the interpretation and application of international penal law be tackled
immediately and effectively. The war crimes trials, at least in Western Europe, have
been held on the basis that the law applied and enforced in these trials is international
law of general application which everyone in the world is generally bound to observe.
In re Yamashita, 327 U.S. 1 (1946).
10 USCS § 847.
10 U.S.C. § 848 provides for 30 days’ confinement or a fine of $100, or both, for any person
who disturbs the proceedings.
10 U.S.C. § 849. Such evidence is inadmissible in a capital case in a court-martial proceeding.
10 U.S.C. § 850.
10 U.S.C. § 836. The President may prescribe rules
(a) Pretrial, trial, and post-trial procedures, including modes of proof, for cases arising under this
chapter [10 USCS §§ 801 et seq.] triable in courts-martial, military commissions and other military
tribunals, and procedures for courts of inquiry, may be prescribed by the President by regulations
which shall, so far as he considers practicable, apply the principles of law and the rules of evidence
generally recognized in the trial of criminal cases in the United States district courts, but which may
not be contrary to or inconsistent with this chapter [10 USCS §§ 801 et seq.].
(b) All rules and regulations made under this article shall be uniform insofar as practicable.
Exec. Order 12,473, 49 Fed. Reg. 17, 152 (1984). These rules essentially mirror the Federal
Rules of Evidence. See Everett & Silliman, supra note 11, at 517.
In re Yamashita, 327 U.S. at 20. See Everett & Silliman, supra note 11, at 513.
The President realized the necessity of adhering to the Articles of War in convening the military
commission in Ex Parte Quirin. See Evan J. Wallach, The Procedural And Evidentiary Rules of
the Post-World War II War Crimes Trials: Did They Provide An Outline For International Legal
Procedure?, 37 COLUM. J. TRANSNAT'L L. 851, 854 n.11 (1999).
On no other basis can the trials be regarded as judicial proceedings, as distinguished
from political inquisitions.32
There is some historical precedent from which an international norm regarding
procedural rights for accused war criminals might be derived. The Nuremberg Tribunals
provide a good starting point,33 as further refined by the International Criminal Tribunals
for Yugoslavia and Rwanda.34 Perhaps the most recent embodiment of the requirements
of the international law of war is to be found in the procedures of the not-yet-operational
International Criminal Court established by the Rome Statute.
The evidentiary rules used at Nuremberg and adopted by the Tokyo tribunals were
designed to be non-technical, allowing the expeditious admission of “all evidence [the
Tribunal] deems to have probative value.”35 This evidence included hearsay, coerced
confessions, and the findings of prior mass trials.36 While the historical consensus seems
to have accepted that the war crimes commissions were conducted fairly,37 some observers
argue that the malleability of the rules of procedure and evidence could and did have some
unjust results.38 For some, the perception is that “victors’ justice” was all that was sought.
Possible Challenges. Although federal courts do not necessarily have jurisdiction
to review the decisions of non-Article III courts, a defendant sentenced by a military
commission may file a writ of habeas corpus39 challenging the jurisdiction of the
commission under of the law of war, the Constitution, relevant statutes, or military
regulations. Because of Congress’ power to define and punish violations of international
law, and due to national security implication, courts are likely to defer to the political
branches for an interpretation of the law of war. A defendant might also challenge a
conviction based on an alleged violation of his right to due process, but case law
demonstrates the difficulties such a challenge would face.40
Telford Taylor, An Outline of the Research and Publication Possibilities of the War Crimes
Trials, 9 LA. L. REV. 496, 507 (1948-49) (cited in Wallach, supra note 30, at 852.)
See Wallach, supra note 30, at 860 (noting that the rules formulated in accordance with the
London Agreement of August 8, 1945, by the Allies setting trial procedures for German war
criminals, served as a model for subsequent tribunals). The rules used at the Nuremberg trials
were, in turn, largely modeled after American military commissions. See id. at 851.
See Major Marsha V. Mills, War Crimes in the 21st Century, 3 HOFSTRA L. & POL'Y SYMP.
47, 55-56 (1999)(describing due process and evidentiary rules of the tribunals).
See Wallach, supra note 30, at 860.
See id. at 871-72.
See id. at 852 (citing VIRGINIA MORRIS & MICHAEL SCHARF, 1 AN INSIDER'S GUIDE TO THE
INTERNATIONAL CRIMINAL TRIBUNAL FOR THE FORMER YUGOSLAVIA 9-10 (1995)).
See Wallach, supra note 30, at 869; Application of Homma, 327 U.S. 759, 760 (1946) (Murphy,
Ex Parte Quirin at 24-25; Colepaugh v. Looney, 235 F.2d 429 (1956). But see Eisentrager v.
Johnson, 339 U.S. 763, 777-781 (1950)(alien captured overseas not entitled to habeas corpus
See, e.g., Burns v. Wilson, 346 U.S. 137 (1953)(declining to review merits of habeas corpus
challenges to convictions by court-martial).