Roger L. Gregory, judge of the United States Court of Appeals for the 4th District, had a question.

The response he got was seriously unnerving.

Gregory is hearing the case of Ali al-Marri, a Qatari citizen and Bradley University student arrested in 2001 as an alleged al-Qaida sleeper agent and held without charges in military detention as an enemy combatant since 2003. His attorneys are in court asking that he be either charged or released.

According to the New York Times, Gregory asked federal prosecutor David Salmons, “What would prevent you from plucking up anyone and saying, ‘You are an enemy combatant’?”

Answer: nothing. And that does mean “anyone.”

Salmons explained that the executive did indeed have that power in wartime, and that “a citizen, no less than an alien, can be an enemy combatant.”

Meaning that a U.S. citizen could be picked up as an enemy combatant and held without charges until the end of the Global War on Terror.

Talk about consecutive life terms.

This part of the issue isn’t so much about al-Marri, who the government says trained at Osama bin Laden’s camp in Afghanistan and had (and was using) 1,000 fraudulent credit card numbers on his computer. (Although, as another judge pointed out, that’s actually a crime that could fit an actual trial and sentencing, and al-Marri was about to have that trial when the president instead declared him an enemy combatant.) Besides, the government notes, the Military Commissions Act passed last fall bans federal courts from considering habeas corpus pleas from alien enemy combatants.

What’s striking is the government’s breezy claim that it can pick up and indefinitely hold anyone, leading one judge to ask if the president could decide someone from People for the Ethical Treatment of Animals was an enemy combatant. Salmons responded cheerfully that “The representative of PETA can sleep well at night,” because, hey, the government is very careful about this.

Although whether it is or not is no business of the court system.

“I think it’s been the president’s position that any combatant, citizen or not, can be held indefinitely,” commented Stephen Saltzburg, who teaches law at George Washington University and is on the American Bar Association’s President’s Advisory Group on Citizen Detention and Enemy Combatant Issues. “The president’s made clear that he thinks he has that power.”

On the other hand, “They don’t like talking about it very much.”

Sometimes, though, it does slip out.

On Thursday, Erik Ablin of the U.S. Department of Justice explained, “The U.S. Supreme Court recognized in the Hamdi case (concerning a U.S. citizen captured fighting in Afghanistan) that the United States may detain American citizens, who are part of or supporting enemy forces, for the duration of hostilities, whether or not they are charged with a specific crime.”

But the Hamdi ruling also declared, “A state of war is not a blank check for the president when it comes to the rights of the nation’s citizens.” Moreover, it said that Hamdi did have some rights, which led to his being released.

That part, it seems, doesn’t matter much to the Justice Department. From Salmons’ answer, and from the department’s statement, it’s the firm position of the Bush administration that U.S. citizens can be declared enemy combatants and held in military detention, without charges and without any meddling by the federal judiciary, until the entire Middle East is governed by secular democracies.

From that position, you can see why the Justice Department is baffled that anybody would ask questions about its right to open mail or listen to telephone calls, and why anyone would think that federal judges needed to be involved in any of that.

It’s hard to know just how comfortable People for the Ethical Treatment of Animals, or any other U.S. citizens, ought to feel about that.

But you could see why, in this atmosphere, Judge Gregory might want to be careful about the questions he asks.