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of war, the status, rights and duties of enemy nations as well as of enemy individuals." By the Articles of War, and especially Article 15, Congress has explicitly provided, so far as it may constitutionally do so, that military tribunals shall have jurisdiction to try offenders or offenses against the law of war in appropriate cases. Congress, in addition to making rules for the government of our Armed Forces, has thus exercised its authority to define and punish offenses against the law of nations by sanctioning, within constitutional limitations, the jurisdiction of military commissions to try persons for offenses which, according to the rules and precepts of the law of nations, and more particularly the law of war, are cognizable by such tribunals. And the President, as Commander in Chief, by his Proclamation in time of war has invoked that law. By his Order creating the present Commission he has undertaken to exercise the authority conferred upon him by Congress, and also such authority as the Constitution itself gives the Commander in Chief, to direct the performance of those functions which may constitutionally be performed by the military arm of the nation in time of war.

An important incident to the conduct of war is the adoption of measures by the military command not only to repel and defeat the enemy, but to seize and subject to disciplinary measures those enemies who in their attempt to thwart or impede our military effort have violated the law

5 Talbot v. Janson, 3 Dall. 133, 153, 159-61; Talbot v. Seeman, 1 Cranch 1, 40-41; Maley v. Shattuck, 3 Cranch 458, 488; Fitzsimmons v. Newport Ins. Co., 4 Cranch 185, 199; The Rapid, 8 Cranch 155, 159-64; The St. Lawrence, 9 Cranch 120, 122; Thirty Hogsheads of Sugar v. Boyle, 9 Cranch 191, 197-98; The Anne, 3 Wheat. 435, 447-48; United States v. Reading, 18 How. 1, 10; Prize Cases, 2 Black 635, 666-67, 687; The Venice, 2 Wall. 258, 274; The William Bagaley, 5 Wall. 377; Miller v. United States, 11 Wall. 268; Coleman v. Tennessee, 97 U. S. 509, 517; United States v. Pacific Railroad, 120 U. S. 227, 233; Juragua Iron Co. v. United States, 212 U. S. 297.

of war. It is unnecessary for present purposes to determine to what extent the President as Commander in Chief has constitutional power to create military commissions without the support of Congressional legislation. For here Congress has authorized trial of offenses against the law of war before such commissions. We are concerned only with the question whether it is within the constitutional power of the National Government to place petitioners upon trial before a military commission for the offenses with which they are charged. We must therefore first inquire whether any of the acts charged is an offense against the law of war cognizable before a military tribunal, and if so whether the Constitution prohibits the trial. We may assume that there are acts regarded in other countries, or by some writers on international law, as offenses against the law of war which would not be triable by military tribunal here, either because they are not recognized by our courts as violations of the law of war or because they are of that class of offenses constitutionally triable only by a jury. It was upon such grounds that the Court denied the right to proceed by military tribunal in Ex parte Milligan, supra. But as we shall show, these petitioners were charged with an offense against the law of war which the Constitution does not require to be tried by jury.

It is no objection that Congress in providing for the trial of such offenses has not itself undertaken to codify that branch of international law or to mark its precise boundaries, or to enumerate or define by statute all the acts which that law condemns. An Act of Congress punishing "the crime of piracy, as defined by the law of nations" is an appropriate exercise of its constitutional authority, Art. I, § 8, cl. 10, "to define and punish" the offense, since it has adopted by reference the sufficiently precise definition of international law. United States v. Smith, 5 Wheat. 153; see The Marianna Flora, 11 Wheat. 1, 40–41;

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United States v. Brig Malek Adhel, 2 How. 210, 232; The Ambrose Light, 25 F. 408, 423-28; 18 U. S. C. § 481. Similarly, by the reference in the 15th Article of War to "offenders or offenses that . . . by the law of war may be triable by such military commissions," Congress has incorporated by reference, as within the jurisdiction of military commissions, all offenses which are defined as such by the law of war (compare Dynes v. Hoover, 20 How. 65, 82), and which may constitutionally be included within that jurisdiction. Congress had the choice of crystallizing in permanent form and in minute detail every offense against the law of war, or of adopting the system of common law applied by military tribunals so far as it should be recognized and deemed applicable by the courts. It chose the latter course.

By universal agreement and practice, the law of war draws a distinction between the armed forces and the peaceful populations of belligerent nations' and also be

• Compare 28 U. S. C. § 41 (17), conferring on the federal courts jurisdiction over suits brought by an alien for a tort "in violation of the laws of nations"; 28 U. S. C. § 341, conferring upon the Supreme Court such jurisdiction of suits against ambassadors as a court of law can have "consistently with the law of nations"; 28 U. S. C. § 462, regulating the issuance of habeas corpus where the prisoner claims some right, privilege or exemption under the order of a foreign state, "the validity and effect whereof depend upon the law of nations"; 15 U.S. C. §§ 606 (b) and 713 (b), authorizing certain loans to foreign governments, provided that "no such loans shall be made in violation. of international law as interpreted by the Department of State."

7 Hague Convention No. IV of October 18, 1907, 36 Stat. 2295, Article I of the Annex to which defines the persons to whom belligerent rights and duties attach, was signed by 44 nations. See also Great Britain, War Office, Manual of Military Law (1929) ch. xiv, §§ 17-19; German General Staff, Kriegsbrauch im Landkriege (1902) ch. 1; 7 Moore, Digest of International Law, § 1109; 2 Hyde, International Law (1922) § 653–54; 2 Oppenheim, International Law (6th ed. 1940) § 107; Bluntschli, Droit International (5th ed. tr. Lardy) §§ 531-32; 4 Calvo, Le Droit International Theorique et Pratique (5th ed. 1896) §§ 2034-35.

1

Opinion of the Court.

tween those who are lawful and unlawful combatants. Lawful combatants are subject to capture and detention as prisoners of war by opposing military forces. Unlawful combatants are likewise subject to capture and detention, but in addition they are subject to trial and punishment by military tribunals for acts which render their belligerency unlawful. The spy who secretly and without uniform passes the military lines of a belligerent in time of war, seeking 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, are familiar examples of belligerents who are generally deemed not to be entitled to the status of prisoners of war, but to be offenders against the law of war subject to trial and punishment by military tribunals. See Winthrop, Military Law, 2d ed., pp. 1196-97, 1219–21; Instructions for the Government of Armies of the United States in the Field, approved by the President, General Order No. 100, April 24, 1863, §§ IV and V.

Such was the practice of our own military authorities before the adoption of the Constitution, and during the Mexican and Civil Wars.10

8

* Great Britain, War Office, Manual of Military Law, ch. xiv, §§ 445-451; Regolamento di Servizio in Guerra, § 133, 3 Leggi e Decreti del Regno d'Italia (1896) 3184; 7 Moore, Digest of International Law, § 1109; 2 Hyde, International Law, §§ 654, 652; 2 Halleck, International Law (4th ed. 1908) § 4; 2 Oppenheim, International Law, § 254; Hall, International Law, §§ 127, 135; Baty & Morgan, War, Its Conduct and Legal Results (1915) 172; Bluntschli, Droit International, §§ 570 bis.

On September 29, 1780, Major John Andre, Adjutant-General to the British Army, was tried by a "Board of General Officers" appointed by General Washington, on a charge that he had come within the lines for an interview with General Benedict Arnold and had been captured while in disguise and travelling under an assumed name. The Board found that the facts charged were true, and that when captured Major Andre had in his possession papers containing in

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Paragraph 83 of General Order No. 100 of April 24, 1863, directed that: "Scouts or single soldiers, if disguised in the dress of the country, or in the uniform of the army hostile to their own, employed in obtaining information, if found within or lurking about the lines of the captor, are treated as spies, and suffer death." And Paragraph telligence for the enemy, and reported their conclusion that "Major Andre . . . ought to be considered as a Spy from the enemy, and that agreeably to the law and usage of nations . . . he ought to suffer death." Major Andre was hanged on October 2, 1780. Proceedings of a Board of General Officers Respecting Major John Andre, Sept. 29, 1780, printed at Philadelphia in 1780.

10 During the Mexican War military commissions were created in a large number of instances for the trial of various offenses. See General Orders cited in 2 Winthrop, Military Law (2d ed. 1896) p. 1298, note 1.

During the Civil War the military commission was extensively used for the trial of offenses against the law of war. Among the more significant cases for present purposes are the following:

On May 22, 1865, T. E. Hogg and others were tried by a military commission, for "violations of the laws and usages of civilized war," the specifications charging that the accused "being commissioned, enrolled, enlisted or engaged" by the Confederate Government, came on board a United States merchant steamer in the port of Panama “in the guise of peaceful passengers" with the purpose of capturing the vessel and converting her into a Confederate cruiser. The Commission found the accused guilty and sentenced them to be hanged. The reviewing authority affirmed the judgments, writing an extensive opinion on the question whether violations of the law of war were alleged, but modified the sentences to imprisonment for life and for various periods of years. Dept. of the Pacific, G. O. No. 52, June 27, 1865.

On January 17, 1865, John Y. Beall was tried by a military commission for "violation of the laws of war." The opinion by the reviewing authority reveals that Beall, holding a commission in the Confederate Navy, came on board a merchant vessel at a Canadian port in civilian dress and, with associates, took possession of the vessel in Lake Erie; that, also in disguise, he unsuccessfully attempted to derail a train in New York State, and to obtain military information. His conviction by the Commission was affirmed on the ground that he was both a spy