A military tribunal isn't an option for U.S. citizens. Treason requires at least two witnesses - which may be hard to find in hostile territory. And it gets even murkier if the Americans fired at Afghans, but not U.S. soldiers.
That's the initial analysis of legal experts intrigued by the U.S. announcement Monday that three people claiming to be Americans and fighting for the Taliban have been taken in custody.
One, John Walker, 20, even claims to have survived a bloody prison riot where a CIA operative was killed in the first American combat death in Afghanistan.
A case against Walker ``would be a tricky thing to prosecute because the Constitution requires two eyewitnesses to the act of treason,'' said University of North Carolina law professor Eric Muller. ``I would think somebody in the Justice Department will have to take a very careful look at this.''
Any prosecutions of U.S. citizens would be before civilian courts because President Bush's military tribunals are reserved for foreign nationals engaging in or supporting terrorism, Georgetown University law professor Mark Tushnet said.
Few details emerged about the other two people taken into custody in Afghanistan who claimed to be Americans, but Walker was in a group of around 80 Taliban fighters holed up for six days in a basement of the Qalai Janghi fort. They were hiding from northern alliance soldiers who had put down a riot by Taliban prisoners in the fortress.
Rear Adm. John Stufflebeem, the deputy director of operations for the Joint Chiefs of Staff, said Walker ``is somebody who claims to be an American citizen. That claim is being respected for the moment, until facts can be established.''
If Walker turns out to be a U.S. citizen, constitutional law professor Sanford Levinson of the University of Texas cited several complexities in prosecuting him.
``If there were two American soldiers who saw him firing at U.S. forces, that might make it, but if he fired at the northern alliance, you're back to some very difficult questions,'' Levinson said.
Muller agreed: ``My initial instinct is that shooting at northern alliance soldiers would not be a crime. I would analogize him to a mercenary in someone else's war. If I wanted to go join the French when they go fight Italy, it's kind of my business.''
Levinson said: ``The question is, what is his status? If he's a prisoner of war, all the other Taliban with him are prisoners of war and that raises a set of issues about whether the Geneva Convention is being adhered to. If he's not a POW, then what is he? A criminal? The White House doesn't want to go that route because criminals usually have rights.''
The Bush administration's plan for war-related prosecutions apparently contemplated all scenarios but one: American fighters on the side of the Taliban.
``For an American citizen, the obvious criminal remedy is a treason prosecution in federal court - a capital crime that is eligible for the death penalty,'' said St. John's University law school professor John Barrett.
Barrett noted that during and after World War II, some treason prosecutions in federal court resulted in long criminal sentences for U.S. saboteurs captured before they could carry out their missions.
But Muller pointed to other potential drawbacks in a case against Walker.
``His age, whether there was any evidence of coercion on the part of those around him - a prosecutor would take all of that into account before deciding whether to proceed,'' said Muller.
