By the law of war, lawful combatants are subject to capture and detention as prisoners of war; unlawful combatants, in addition, are subject to trial and punishment by military tribunals for acts which render their belligerency unlawful.
It has long been accepted practice by our military authorities to treat those who, during time of war, pass surreptitiously from enemy territory into our own, discarding their uniforms upon entry, for the commission of hostile acts involving destruction of life or property, as unlawful combatants punishable as such by military commission. This practice, accepted and followed by other governments, must be regarded as a rule or principle of the law of war recognized by this Government by its enactment of the Fifteenth Article of War.
Citizens of the United States who associate themselves with the military arm of an enemy government, and with its aid, guidance and direction enter this country bent on hostile acts, are enemy belligerents within the meaning of the Hague Convention and the law of war.
Even when committed by a citizen, the offense here charged is distinct from the crime of treason defined in Article III, @ 3 of the Constitution, since the absence of uniform essential to one is irrelevant to the other.
Article III, @ 2, and the Fifth and Sixth Amendments of the Constitution did not extend the right to demand a jury to trials by military commission or require that offenses against the law of war, not triable by jury at common law, be tried only in civil courts.