refresher on Graham's-Kav cases in the questions
start with Operation Pastorius 1942 (dig to find the 2 American Citizens. not all were technically "german")(Roosevelt gave us this one)
https://en.m.wikipedia.org/wiki/Operation_Pastorius
Out of the above came…
Ex Parte Quirin, 317 U.S. 1 (1942)
https://supreme.justia.com/cases/federal/us/317/1/
Johnson v. Eisentrager, 339 U.S. 763 (1950)
https://supreme.justia.com/cases/federal/us/339/763/
Hamdi v. Rumsfeld, 542 U.S. 507 (2004)
https://supreme.justia.com/cases/federal/us/542/507/