As we recognized in Rasul, 542 U. S., at 476; id., at 487 (KENNEDY, J., concurring in judgment), the outlines of a framework for determining the reach of the Suspension Clause are suggested by the factors the Court relied upon in Eisentrager. In addition to the practical concerns discussed above, the Eisentrager Court found relevant that each petitioner:

“(a) is an enemy alien; (b) has never been or resided in the United States; (c) was captured outside of our territory and there held in military custody as a prisoner of war; (d) was tried and convicted by a Military Commission sitting outside the United States; (e) for offenses against laws of war committed outside the United States; (f) and is at all times imprisoned outside the United States.” 339 U. S., at 777. Based on this language from Eisentrager, and the reasoning in our other extraterritoriality opinions, we conclude that at least three factors are relevant in determining the reach of the Suspension Clause: (1) the citizenship and status of the detainee and the adequacy of the process through which that status determination was made; (2) the nature of the sites where apprehension and then detention took place; and (3) the practical obstacles inherent in resolving the prisoner’s entitlement to the writ.

In the lower court decisions in Boumediene, the decisions simply misread Eisentrager. The SCOTUS gets it right today. I previously wrote about the Boumediene decisions:

Now we come to Judge Robertson's most grievous error:

Hamdan's lengthy detention beyond American borders but within the jurisdictional authority of the United States is historically unique. Nevertheless, . . . his connection to the United States lacks the geographical and volitional predicates necessary to claim a constitutional right to habeas corpus.

This is simply a complete misreading of Eisentrager. What did Eisentrager say on this point?

We are here confronted with a decision whose basic premise is that these prisoners are entitled, as a constitutional right, to sue in some court of the United States for a writ of habeas corpus. To support that assumption we must hold that a prisoner of our military authorities is constitutionally entitled to the writ, even though he (a) is an enemy alien; (b) has never been or resided in the United States; © was captured outside of our territory and there held in military custody as a prisoner of war; (d) was tried and convicted by a Military Commission sitting outside the United States; (e) for offenses against laws of war committed outside the United States; (f) and is at all times imprisoned outside the United States.

Look at the facts the Eisentrager Court rel[ied] [up]on - the petitioner[s] ARE enemy aliens. The petitioners are being held OUTSIDE US territory. The petitioner were tried OUTSIDE of US territory. The petitioners were at all times imprisoned OUTSIDE of US territory.

None of these are accepted facts in [Boumediene]. And these are no mere details. They are central to the Eisentrager decision. It is the fact that the petitioners were enemy aliens - an undisputed fact - that [wa]s paramount in Eisentrager.

The Court today notes this distinction from Eisentrager:

Applying this framework, we note at the onset that the status of these detainees is a matter of dispute. The petitioners, like those in Eisentrager, are not American citizens.

But the petitioners in Eisentrager did not contest, it seems, the Court’s assertion that they were “enemy alien[s].” Ibid. In the instant cases, by contrast, the detainees deny they are enemy combatants. They have been afforded some process in CSRT proceedings to determine their status; but, unlike in Eisentrager, supra, at 766, there has been no trial by military commission for violations of the laws of war.

Precisely. As Justice Souter's concurrence states, this decision was no "bolt from the blue." Rasul practically dictated this decision:

Four years ago, this Court in Rasul v. Bush, 542 U. S. 466 (2004) held that statutory habeas jurisdiction extended to claims of foreign nationals imprisoned by the United States at Guantanamo Bay, “to determine the legality of the Executive’s potentially indefinite detention” of them, id., at 485. Subsequent legislation eliminated the statutory habeas jurisdiction over these claims, so that now there must be constitutionally based jurisdiction or none at all. JUSTICE SCALIA is thus correct that here, for the first time, this Court holds there is (he says “confers”) constitutional habeas jurisdiction over aliens imprisoned by the military outside an area of de jure national sovereignty, see post, at 1 (dissenting opinion). But no one who reads the Court’s opinion in Rasul could seriously doubt that the jurisdictional question must be answered the same way in purely constitutional cases, given the Court’s reliance on the historical background of habeas generally in answering the statutory question. . . . Of course, it takes more than a quotation from Rasul, however much on point, to resolve the constitutional issue before us here, which the majority opinion has explored afresh in the detail it deserves. But whether one agrees or disagrees with today’s decision, it is no bolt out of the blue.