All the German saboteurs in Quirin were captured on U.S. soil. Two of them claimed to be U.S. citizens. The Supreme Court said it did not matter if they were, so it did not bother to consider whether their claim was correct. Which implies that U.S. citizens captured on U.S. soil can be treated as enemy combatants (at least in circumstances like those of that case.)
EVEN MORE ENEMY COMBATANT BREAKING NEWS -- Divided three-judge Ninth Circuit panel holds that federal district courts have jurisdiction to consider habeas petitions of uncharged foreign detainees held at Guantanamo Naval Base: You can access the ruling, issued just moments ago, at this link. Circuit Judge Stephen Reinhardt wrote the majority opinion, in which Senior District Judge Milton I. Shadur, sitting by designation from the U.S. District Court for the Northern District of Illinois, joined. Circuit Judge Susan P. Graber dissented. In an unpublished order issued today, the panel has stayed the issuance of its mandate pending the U.S. Supreme Court's resolution of a case presenting this very same issue.
posted at 1:30 PM by Howard Bashman
(I've omitted the links, which you can get by going to the How Appealing site.)