Updated

In the year since the Sept. 11 attacks, civil liberties for some people have fallen into a surreal legal limbo. Yaser Esam Hamdi is an example.

Hamdi was captured in Afghanistan, sent to Guantanamo, then transferred to a Norfolk, Va., military brig after the Defense Department learned that he was a U.S. citizen. Hamdi is being detained indefinitely, without seeing an attorney, even though he hasn't been charged with any crime.

Jose Padilla, who allegedly plotted to build a radiological "dirty bomb," is also a U.S. citizen. He, too, is being detained by the military -- indefinitely, without seeing an attorney, even though he hasn't been charged with any crime.

Meanwhile, Zacarias Moussaoui, purportedly the 20th hijacker, is not a U.S. citizen. Neither is Richard Reid, the accused shoe bomber. Both have attorneys. Both are being tried before federal civilian courts.

What gives? Four men: two citizens and two non-citizens. Is it possible that constitutional rights -- like habeas corpus, which requires the government to justify continued detentions, and the Sixth Amendment, which assures a speedy and public jury trial with assistance of counsel -- can be denied to citizens yet extended to non-citizens? That's what the Bush administration would have us believe.

Citizen Hamdi's treatment is legitimate, insists Attorney General John Ashcroft, because Hamdi is an "enemy combatant" and there is "clear Supreme Court precedent" to handle those persons differently, even if they are citizens. Ashcroft's so-called clear precedent is a 1942 Supreme Court case, Ex Parte Quirin, which dealt with Nazi saboteurs, at least one of whom was a U.S. citizen.

"Enemy combatants," said the Court, are either lawful -- for example, the regular army of a belligerent country -- or unlawful -- for example, terrorists. When lawful combatants are captured, they are prisoners of war, POWs. As POWs, they cannot be tried (except for war crimes). They must be repatriated after hostilities are over, and they only have to provide their name, rank, and serial number if interrogated.

Clearly, that's not what the Justice Department had in mind for Hamdi.

Unlawful combatants are different. When unlawful combatants are captured, they can be tried by a military tribunal. That's what happened to the Nazi saboteurs in Quirin. But Hamdi has not been charged, much less tried.

Indeed, the president's executive order of November 2001 excludes U.S. citizens from the purview of military tribunals. If the president were to modify his order, the Quirin decision might provide legal authority for the military to try Hamdi. But the decision provides no legal authority for detaining a citizen without an attorney solely for purposes of aggressive interrogation.

Moreover, the Constitution does not distinguish between the protections extended to ordinary citizens on one hand and unlawful combatant citizens on the other. Nor does the Constitution distinguish between crimes covered by the Fifth and Sixth Amendments and terrorist acts. Still, the Quirin Court justified those distinctions, noting that Congress had formally declared war and thereby invoked articles of war that authorized the trial of unlawful combatants by military tribunal.

Today, the situation is different. We'vehad virtually no input from Congress: no declaration of war, no authorization of tribunals, and no legislative suspension of habeas corpus. Yet those functions are assigned to Congress by Article I of the Constitution. It is Congress, not the executive branch, which has the power "To declare War" and "To constitute Tribunals inferior to the supreme Court."

Only Congress can suspend the "Privilege of the Writ of Habeas Corpus ... when in Cases of Rebellion or Invasion the public Safety may require it."

Without either constitutional or statutory authority, the administration has decided that it will set the rules, prosecute infractions, determine guilt or innocence, then review the results of its own actions. That's too much unchecked power in the hands of the president. We cannot permit the executive branch to declare unilaterally that a U.S. citizen may be characterized as an enemy combatant, whisked away, detained indefinitely without charges, denied legal counsel, and prevented from arguing to a judge that he is innocent.

That does not mean the Justice Department must set people free to unleash weapons of mass destruction. But it does mean, at a minimum, that Congress must get involved and exercise its responsibility to enact a new legal regimen for citizen-detainees in time of national emergency. That regimen must respect citizens' rights under the Constitution, including the right to judicial review of executive branch decisions.

When the executive, legislative, and judicial branches agree on the framework, the potential for abuse is diminished. When only the executive has acted, the foundation of a free society starts to erode.

Robert A. Levy is senior fellow in constitutional studies the Cato Institute.