Three Army judges are weighing a question that hasn't cropped up in decades: whether a civilian contractor working for the U.S. military can be tried in a military court. The issue eventually could end up at the Supreme Court.

The case of Alaa "Alex" Mohammad Ali, a former Army translator in Iraq, challenges the notion that courts-martial only have authority over members of the armed forces. But it also runs up against complaints that using U.S. civilian courts to prosecute contractors working with U.S. forces in Afghanistan and Iraq has been largely ineffective, and trying them in local courts often has not been possible.

Ali, an Iraqi-Canadian, was prosecuted by the military after an altercation in Iraq during which he allegedly stole a U.S. soldier's knife and used it to stab another translator. He pleaded guilty to lesser charges.

Ali's appeal is before the Army Court of Criminal Appeals. He was convicted under rules issued after Congress amended the Uniform Code of Military Justice in 2006 to allow courts-martial of civilians in Iraq and Afghanistan.

At a hearing Wednesday, the three Army colonels serving as judges wondered how far the military's authority could extend when civilians are involved. "Does citizenship matter?" Col. Theresa Gallagher asked.

Maj. Adam Kazin, representing the Army, said the rules would apply equally to Americans and foreigners.

Capt. Tiffany Dewell, Ali's lawyer, said that almost anyone accompanying troops in the field, including embedded reporters and Red Cross workers, potentially could be affected. The new rules have not been applied to U.S. citizens.