Congress has recently authorized military commissions to try enemies not only for violations of the international law of war, but also for domestic-law offenses, such as providing material support to terrorism and conspiring to commit law-of-war offenses. Moreover, President Trump has indicated support for further military trials, including trials against U.S. citizens. Such military tribunals lack the civilian jury and independent judge that Article III of the Constitution prescribes. The constitutionality of such an abrogation of Article III’s criminal trial guarantees has been debated during many of the nation’s wars without clear resolution, and the constitutional question is now at the heart of a potentially landmark case, al Bahlul v. United States, currently before the Supreme Court.