In a jail guarded by U.S. military police on the outskirts of Baghdad, at a base where U.S. interrogators do the questioning, Iraqi American Mohammad Munaf and Jordanian American Shawqi Ahmad Omar are stuck in a peculiar legal limbo.

Munaf and Omar say their jailers at Camp Cropper are under U.S. Army command, and therefore they are entitled to challenge their detention under U.S. law. But the Bush administration has argued in court that the prison belongs to the international military coalition called Multi-National Force-Iraq and that Munaf and Omar are, therefore, beyond the reach of U.S. courts.

The dispute is scheduled to be taken up by the Supreme Court on Tuesday, and the outcome could have broad implications for the rights of U.S. citizens held on international battlefields. Until the court rules, the extent of U.S. constitutional protections overseas remains unclear.

"Habeas corpus, the power of the courts to review detention by the executive, has existed in some form for over seven hundred years," American Bar Association President William H. Neukom told the court in a brief. "It remains, in the context of military detentions of this country's citizens, a vital protection of the rule of law."

The largely parallel legal claims of the two men are complicated by their controversial personal sagas. Munaf was jailed in Camp Cropper as the result of a strange kidnapping incident involving three Romanian journalists he was escorting through Baghdad. He and the journalists were taken to a tiny concrete dungeon beneath a farmhouse on the city's outskirts, where they were held with seven other hostages, bound and blindfolded for nearly two months.

After Munaf and the journalists were released, U.S. and Romanian authorities accused him of setting up the kidnapping. The U.S. government contends in court papers that Munaf "admitted on camera, in writing, and in front of the Iraqi investigative court" that he was an accomplice.