Definition
Military commissions are ad hoc tribunals convened by military authority to try individuals — typically unlawful combatants, enemy belligerents, or civilians in occupied territory — for violations of the laws of war and related offenses. They are distinct from courts-martial, which are permanent military courts that try members of a nation's own armed forces under domestic military law. Military commissions operate outside the ordinary civilian court system and, historically, outside the formal military justice system as well.
The term encompasses at least three overlapping uses:
1. WARTIME TRIBUNALS FOR ENEMY COMBATANTS: The primary modern usage. Military commissions convene to try enemy fighters or suspected terrorists for war crimes, espionage, and related offenses. Post-9/11 U.S. commissions established under the Military Commissions Acts of 2006 and 2009 are the most prominent contemporary example.
2. OCCUPATION COURTS: Historically, military commissions served as the governing judicial body in occupied or conquered territory where civil courts had ceased to function. In this role they exercised broad jurisdiction over both civilians and enemy nationals.
3. MARTIAL LAW TRIBUNALS: Where martial law is declared domestically, military commissions may be convened to try civilians alleged to have violated martial law orders. This usage is the most constitutionally contested and has largely been repudiated by modern doctrine.
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Common Confusion
MILITARY COMMISSIONS vs. COURTS-MARTIAL: Courts-martial are statutory tribunals governed by the Uniform Code of Military Justice and used to prosecute members of the U.S. armed forces for violations of military law. Military commissions are used to prosecute non-members — enemy combatants, unlawful belligerents — for violations of the laws of war. The procedural protections differ significantly. Researchers and general readers frequently conflate these, particularly when coverage focuses on military justice broadly.
MILITARY COMMISSIONS vs. MILITARY TRIBUNALS: The terms are often used interchangeably in popular usage and in some historical sources. Technically, "military tribunal" is the broader category; military commissions are one type. Courts-martial are also a type of military tribunal. In legal and research contexts, precision matters: "military commission" carries specific procedural and jurisdictional connotations that "military tribunal" does not.
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Core Elements
For a military commission to have valid jurisdiction under established U.S. doctrine, several conditions have generally been required:
1. PROPER AUTHORITY: The commission must be convened by an officer with lawful authority — traditionally the President as Commander in Chief, or a theater commander acting under delegated authority. Statutory authorization strengthens legitimacy significantly.
2. PROPER SUBJECT MATTER: Jurisdiction is limited to offenses against the laws of war and related offenses cognizable under the law of nations. The scope of cognizable offenses has been contested; Hamdan v. Rumsfeld (2006) held that conspiracy, as charged, was not a triable law-of-war offense before a commission.
3. PROPER PERSON: The accused must fall within the category of persons subject to commission jurisdiction — historically, unlawful combatants and enemy belligerents. Whether U.S. citizens can be tried by military commission is a deeply contested constitutional question.
4. COMPLIANCE WITH THE LAWS OF WAR: The commission's procedures must at minimum comply with the requirements of international humanitarian law and, following Hamdan, with Common Article 3 of the Geneva Conventions.
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Why It Matters in Research
Military commissions present layered research challenges because the term carries different legal weight across three distinct periods: the Civil War and Reconstruction era, World War II, and the post-9/11 period. Sources from each period use the same terminology to describe procedurally and constitutionally distinct institutions.
Civil War-era commissions, including those used to try Lincoln assassination conspirators, operated under virtually no statutory framework and minimal judicial oversight. Researchers should not assume that procedural rules or constitutional constraints recognized in modern cases applied to these historical bodies.
World War II commissions — particularly Ex parte Quirin (1942) — established precedents that the post-9/11 era initially relied upon heavily, but Hamdan v. Rumsfeld significantly qualified Quirin's reach. Reading post-2006 materials that cite Quirin without also engaging Hamdan will produce a distorted picture.
The Military Commissions Acts of 2006 and 2009 created a statutory framework that substantially changed the legal landscape. Pre-2006 sources discussing the "legal basis" for military commissions may be describing executive-only authority that no longer reflects current doctrine. Conversely, sources written in the immediate aftermath of 9/11 and before Hamdan reflect a legal environment that was subsequently repudiated in significant respects.
Jurisdictional stripping provisions in the 2006 MCA — limiting habeas corpus — were partially invalidated by Boumediene v. Bush (2008). Researchers working on detention and commission jurisdiction must treat 2006-2008 sources with particular caution; the legal ground shifted rapidly and some contemporaneous commentary is now outdated.
For researchers focused on the law of war, the question of which offenses are triable before a commission (as opposed to requiring a court-martial or civilian prosecution) remains unsettled. Al Bahlul v. United States (D.C. Cir. 2014 and subsequent proceedings) continued to work through this question years after the MCA's passage.
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Historical Dictionary Support
Black's Law Dictionary captures the core institutional description accurately: military commissions are courts "whose procedure and composition are modeled upon courts-martial, being the tribunals by which alleged violations of martial law are tried and determined." This framing is useful but reflects an older emphasis on martial law as the primary context. Modern doctrine has moved away from the martial law framing toward a laws-of-war framework, and Black's older editions do not fully anticipate the post-9/11 statutory regime.
The historical sources agree on the basic distinction between commissions and courts-martial but are largely silent on the constitutional constraints that twentieth and twenty-first century litigation imposed. Researchers relying solely on Black's older definitions will miss the entire constitutional architecture built up through Quirin, Hamdan, and Boumediene. No pre-2006 dictionary entry adequately captures the current framework.
Historical dictionaries also tend to treat military commissions as instruments of military necessity with broad, flexible jurisdiction. Contemporary doctrine has substantially narrowed that flexibility — particularly regarding subject matter jurisdiction and procedural due process — and researchers should weight modern case law and statutory text over dictionary definitions when the question is a live legal one.
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Jurisdictional Note
Military commissions are a matter of federal law in the United States; states have no parallel institution. Internationally, other nations and international tribunals use analogous bodies under different names and legal frameworks. Comparative research should not assume that foreign or international military tribunal doctrine maps onto U.S. military commission law.
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Encyclopedia Cross-Reference
The Law Mind Constitutional Law Encyclopedia — Military Tribunals and Commissions: Constitutional Limits (Hamdan v. Rumsfeld)
The Law Mind Military, Veterans & Admiralty Law Encyclopedia — Military Rules of Evidence and the Military Judge's Role
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