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.