Hamdi vs. Rumsfeld, 542 U.S. 507 (2004)- enemy combatants can be detained, even if they are U.S. citizens.
Ex parte Quirin, 317 U.S. 1 (1942)- a military commission can be established for unlawful combatants.
Ex parte Milligan- 71 U.S. (4 Wall.) 2 (1866)- Trying citizens in military courts is unconstitutional when civilian courts are still operating. Trial by military tribunal is constitutional only when there is no power left but the military, and the military may validly try criminals only as long as is absolutely necessary.
It reminds me of he photo of President Trump and all those high ranking military officers. Why did so many of them not last?