\u27De Facto Sovereignty\u27: \u3cem\u3eBoumediene\u3c/em\u3e and Beyond

In Boumediene v. Bush, which grants non-citizens detained at Guantanamo Bay, Cuba, constitutional habeas corpus privileges the Supreme Court took notice that the United States maintains de facto sovereignty over that territory. As its sole precedential support, the Court cited a case that never mentions the term de facto sovereignty. What is this concept? How important is it to the Court\u27s holding? Did the Court get the concept right given its longstanding usage and meaning in Supreme Court precedent? And what can de facto sovereignty tell us about when the Court will find habeas to extend to other situations involving extraterritorial detention of non-citizens in the war on terror