Abstract: This Article provides a broad-lens, synoptic perspective on war-on-terrorism questions arising within the habeas corpus jurisdiction of the federal courts. Analytically, it develops a clear framework for sorting out the tangle of jurisdictional, substantive, procedural, and scope-of-review issues that habeas cases often present. Methodologically, it champions a common law—like approach to habeas adjudication under which courts must exercise responsible judgment in adapting both statutory and constitutional language to unforeseen exigencies. The Article also takes substantive positions on a number of important issues. In the jurisdictional domain, it defends the Supreme Court’s controversial decision in Rasul v. Bush, which interpreted the habeas statute as it then stood to authorize inquiry into the lawfulness of detentions at Guantí¡namo Bay. The Article also argues, however, that a court would overstep if it read the Constitution as mandating review of detentions of aliens in such wholly foreign locales as Afghanistan or Iraq. Scrutinizing post-Rasul legislation that eliminates habeas for alien detainees and substitutes more limited review in the D.C. Circuit, the Article argues that the resulting scheme is constitutionally valid as applied to most cases in which the D.C. Circuit can exercise review, but invalid insofar as it entirely precludes detainees in the United States or at Guantí¡namo Bay from challenging their detention or conditions of confinement before a civilian court. With respect to substantive rights, the Article argues that American citizens seized outside of battlefield conditions have a right not to be detained indefinitely without civilian trial. It explains why the constitutional rights of noncitizens are more limited, but argues that existing statutes should not be read to authorize aliens’ detention as enemy combatants when they are seized in the United States, away from any theater of combat. Finally, the Article analyzes some of the most important procedural and scope-of-review questions likely to come before habeas courts.