What power has the government to detain and interrogate American citizens and others whom it suspects of links to foreign enemies but cannot criminally prosecute without harming its ability to gather intelligence? And what rights have such people to challenge the government’s claims that they are "enemy combatants"?

It has now become clear that the Supreme Court is likely to decide three cases turning on these critical legal questions — the most momentous of all those raised by the war against terrorism — by July. The Bush administration on January 7 urged the justices to review on an expedited basis and reverse a December 18 federal appeals court decision barring the continued military detention without trial of Jose Padilla, a U.S. citizen arrested in Chicago on suspicion of plotting a dirty-bomb attack for Al Qaeda. Since June 2002, he has been subjected to indefinite, virtually incommunicado detention, without ever seeing a lawyer or a judge, as a suspected "enemy combatant." The Court also has before it a petition for review by another U.S. citizen alleged to be an enemy combatant, Yaser Esam Hamdi, who was apparently captured in Afghanistan by the Northern Alliance in late 2001 and is imprisoned in the same South Carolina military brig that holds Padilla. And the justices agreed in November to hear arguments on the Bush administration’s claim of absolute power — unreviewable by any court in the world — over the more than 600 foreigners imprisoned as enemy combatants at the Guantanamo naval base in Cuba.

It is none too soon for the Court to address these issues. The administration’s handling of the "enemy-combatant" cases has been so lawless as to smack of tyranny. Indeed, its denial of any semblance of due process to Padilla and Hamdi has been called "unsustainable" by the drafter of the USA PATRIOT Act, Viet Dinh, who was a high-level Bush Justice Department appointee. (The act said nothing about detention of enemy combatants.) Congress has abdicated its own duty to create a legal framework for detaining suspected terrorists without eviscerating due process. And lower courts have become hopelessly divided on how to handle such cases.

That division became manifest on December 18, when two federal appeals courts — the 2nd Circuit, in Manhattan, and the 9th Circuit, in San Francisco — handed the administration its two biggest post-9/11 legal defeats. Both decisions were by 2-1, and both reversed earlier rulings by federal district judges.

The 2nd Circuit, in the Padilla case, ruled broadly that the executive branch has no power at all, excepting the normal criminal process, "to detain as an enemy combatant an American citizen seized on American soil outside a zone of combat." This ruling went too far in curbing the president’s wartime powers, apparently leaving him without authority to detain even a citizen suspected of plotting a mass murder for Al Qaeda unless he can be criminally prosecuted or held as a material witness, which might not always be legally possible. The 2nd Circuit decision is also hard to square with the 4th Circuit’s January 2003 ruling in the Hamdi case — which went too far in the other direction, by denying Hamdi any opportunity to see a lawyer or to present evidence challenging the accuracy of the enemy-combatant label. (While the government said in December that it would at last let Hamdi see a lawyer because it had completed his interrogation, it still claims he has no legal right to see a lawyer.)

The 9th Circuit, for its part, held that the Guantanamo prisoners were entitled to challenge their detentions in U.S. courts, because the U.S. has complete control of the base under a perpetual lease from Cuba. This contradicted a ruling for the government last March by the District of Columbia Circuit, which the Supreme Court had already agreed to review.

It’s no accident that lower-court judges are so badly split. They are writing on an essentially blank slate. No Supreme Court precedent provides clear guidance for resolving these issues. Nor has Congress even begun to come to grips with the need for some carefully limited system of preventive detention to deal with the unprecedented threat posed by a mass movement of militant Islamic terrorists who crave martyrdom, hide in shadows, avoid criminal activities that might arouse suspicion before they are ready to strike, and are fanatically bent on slaughtering as many Americans as possible.

Congress’s inaction has been a disgrace. It is paradigmatically a legislative task to design and debate rules to disable suspected terrorists from committing mass murders without eviscerating hundreds of years of legal protections against arbitrary detentions. A key question in the Hamdi and Padilla cases, for example, is whether the generally worded September 2001 act of Congress authorizing war against Al Qaeda and the Taliban was intended to authorize indefinite military detention of American citizens alleged to be members. The 4th Circuit said yes; the 2nd Circuit suggested no. Why should the Supreme Court have to guess? Congress should provide the answer (which should be yes), together with a detailed process for resolving difficult issues such as who is an enemy combatant; how long such combatants can be interrogated before being given hearings at which to challenge their detentions; how sensitive intelligence information should be handled; how long enemy combatants can be held; and how the rights of citizens and noncitizens should differ.

Congressional passivity would have been less harmful — and judicial deference might be warranted — had the Bush administration itself created a fair and transparent process for resolving such issues. But instead, it has flouted the rule of law by locking up these people with no due process at all.

The Guantanamo prisoners have been denied even the hearings that are clearly required by the nation’s treaty obligations to resolve any doubt as to whether they are unlawful combatants, prisoners of war, or mistakenly detained noncombatants. (There clearly is doubt as to many of these prisoners, notwithstanding President Bush’s unsupportable claim to the contrary.) Under the administration’s view of the law, no court could intervene even if Bush were to order all 600-plus Guantanamo detainees lined up and shot.

The administration also seeks to deny meaningful judicial review to Hamdi and Padilla. Its legal position boils down to this: If the president puts the enemy-combatant label on any American citizen (or anyone else), anywhere in the world, the military can hold that person virtually incommunicado, for as long as it chooses, with no access to a lawyer, no right to testify or call witnesses, and a judicial process that amounts to an empty ritual, with courts obliged to ratify whatever factual claims the government makes without hearing any evidence beyond what the government chooses to disclose.

To be sure, the administration does appear to have substantial evidence that Hamdi fought for the Taliban and that Al Qaeda sent Padilla to scout the U.S. for a possible dirty-bomb attack. But the precedent it seeks to establish would effectively bar courts from intervening even to prevent indefinite incarceration of you, me, or, say, a Muslim cleric whose fiery criticisms of U.S. foreign policy annoy officials at the Pentagon.

Nor has the administration been consistent in its treatment of suspected "enemy combatants" — a term it has never defined. It has offered no justification for treating Hamdi and Padilla differently from two similarly situated men whom it criminally indicted: John Walker Lindh, another U.S. citizen captured with a Taliban unit in Afghanistan (who in a plea bargain received a 20-year prison term) and Zacarias Moussaoui, another suspected Qaeda operative captured in the U.S. (whose troubled prosecution is pending).

Small wonder that Viet Dinh — who clerked for Justice Sandra Day O’Connor eight years ago — has expressed doubt that the justices would uphold the administration’s evisceration of due process in the Padilla and Hamdi cases. And small wonder that Michael Chertoff, who headed the Bush Justice Department’s criminal division until last summer and is now a judge on the 3rd Circuit, suggested in a speech in October: "We need to debate a long-term and sustainable architecture for the process of determining when, why, and for how long someone may be detained as an enemy combatant, and what judicial review should be available."

An enlightened administration would heed its former officials’ warnings by seizing the opportunity to establish a legacy of care in balancing the imperatives of liberty and security. There is no indication that the executive-power absolutists who dominate the Bush White House and Pentagon would dream of doing anything so sensible. Unless, perhaps, the Supreme Court fires a loud shot or two across Bush’s bow.