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 between 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.
Eight German-born U.S. residents were captured by the United States as they tried to enter the country during war time, for the purpose of sabotage, espionage, hostile or warlike acts, or violations under the law of war. The President of the United States held that petitioners were to be tried before a military tribunal under the Articles of War. The 8 captured residents challenged the President's authority, arguing that under the U.S. Constitution they had a right to demand a jury trial in the civil courts.
Did belligerents caught entering the United States during wartime have the right to demand a jury trial in the civil courts?
The court found that petitioners were alleged to be unlawful belligerents, and that under the Articles of War, they were not entitled to be tried in a civil proceeding, nor by a jury. The court also determined that trying petitioners before a military court was not illegal and did not violate the U.S. Const. amends. V and VI relating to "crimes" and "criminal prosecutions." Thus, the court affirmed the President's authority to try petitioners before a military tribunal without a jury.