April 20 (Bloomberg) -- U.S. President George W. Bush's war on terrorism faces a Supreme Court showdown over the right of U.S. and foreign citizens seized as ``enemy combatants'' to challenge their detention in military custody.

The justices hear arguments today from lawyers for 14 of about 650 prisoners captured overseas after the Sept. 11, 2001, terrorist attacks and held at Guantanamo Bay Naval Base in Cuba. On April 28, the court hears appeals involving two U.S. citizens in military custody, Yaser Esam Hamdi and Jose Padilla.

The cases will be viewed ``as a court decision on the legality of the war against terrorism,'' said Stephen B. Presser, a Northwestern University professor of legal history who joined a brief backing the Bush administration.

The government says it holds detainees to gather intelligence and prevent new acts of terrorism. The U.S. Constitution allows the president, as commander in chief, to control captured enemies without ``micro-managing'' by the courts, the Bush administration says.

Lawyers for the detainees argue against giving the government such authority with no legal review. ``We're asking the courts not to abdicate their role as the guardian of individual liberty,'' said attorney Frank Dunham, representing Hamdi. ``When a power is given to the executive, it never comes back.''

Slipping in Polls

The court's rulings aren't likely to affect the presidential race between Bush and Democrat John Kerry, said Stuart Rothenberg, editor of the nonpartisan Rothenberg Report in Washington. Kerry, 60, a four-term Massachusetts senator who received a Silver Star and Bronze Star for valor while serving in Vietnam, hasn't attacked Bush on the detainees as he has the president's handling of the war in Iraq and the economy.

``What matters is what the situation looks like in August and September in terms of Iraq, in terms of the war on terrorism and the economy,'' Rothenberg said.

A ruling for the 57-year-old Bush ``accumulates enormous power in the president to make all sorts of decisions in the United States and elsewhere that escape judicial review,'' said Michael Greenberger, a University of Maryland law professor and director of its Center for Health and Homeland Security. Greenberger, who hasn't taken a formal position on the cases, said he expects Bush to lose.

``Bush has gone to the mat on these cases,'' Greenberger said. ``It will be an embarrassment for him'' to lose.

The court will rule by July, before its current term ends.

No Charges

No charges have been filed against Hamdi, Padilla or any of the 14 Guantanamo detainees involved in today's case. The government said one of them, Australian David Hicks, may be charged. Hamdi and Padilla are being held at a navy brig in Charleston, South Carolina, and were allowed no contact with their lawyers until earlier this year.

The Guantanamo detainees, including 12 Kuwaitis and two Australians seized in Afghanistan and Pakistan following the 2001 attacks, want a federal court to order some type of process to let them challenge the government's reasons for holding them. All say they had no involvement in terrorism, and the Kuwaitis say they were humanitarian workers.

``You'd be giving these people an opportunity to say `no, I wasn't there' or `no, I was an aid worker,''' said Jeffrey Fogel, a lawyer for the Guantanamo detainees. The government is claiming ``sole and unchallengeable authority to do anything it wants.''

A federal appeals court in Washington ruled that foreign citizens captured and held abroad have no right to a U.S. court hearing. The Justice Department is urging the Supreme Court to uphold that ruling, saying Bush and the military, not the courts, have the authority to determine the detainees' rights.

1950 Ruling

The Guantanamo detainees seek ``rights that have never been awarded in history to people captured in combat,'' former U.S. Attorney General Edwin Meese said in an interview. Meese, who served under President Ronald Reagan, joined other former government and retired military officials in a brief supporting the administration.

The government relies on a 1950 Supreme Court decision that barred 21 Germans convicted of World War II crimes by an overseas U.S. military court from challenging their convictions in federal court because they were never in U.S. sovereign territory.

Though Padilla and Hamdi are both U.S. citizens, their cases differ because Padilla was arrested in the U.S. while Hamdi, 23, was taken into custody in a combat zone in Afghanistan. The U.S. says Hamdi went to that country to train with and, ``if necessary, fight for the Taliban.''

Padilla was arrested in 2002 in Chicago after arriving on a flight from Pakistan. The government says he was ``closely associated with al-Qaeda'' and intended to explode a radioactive ``dirty bomb'' in the U.S.

Threat `Never Seen Before'

``The president doesn't have the authority to detain an American citizen, seized on American soil, unarmed, to hold him without charge indefinitely,'' Padilla's lawyer, Donna Newman, said in an interview. ``He's not an alien. He's a citizen, and there are rights that attach for very good reason.''

The New York-based 2nd U.S. Circuit Court of Appeals ruled for Padilla in December, saying the military couldn't hold him as an enemy combatant without congressional authorization. The court, which put its ruling on hold pending the Supreme Court appeal, said Padilla still can be charged in criminal court.

In Hamdi's case, the Richmond, Virginia-based 4th U.S. Circuit Court of Appeals barred him from challenging his detention. A government declaration that he was considered an enemy combatant was enough to foreclose any further review, the court said.

The Supreme Court should defer to the government's actions as ``a very simple case of self-defense,'' Northwestern University's Presser said. ``We're facing a threat the likes of which we've never seen before.''

The cases being argued today are Rasul v. Bush, 03-334, and al Odah v. U.S., 03-343. The cases being argued April 28 are Hamdi v. Rumsfeld, 03-6696, and Rumsfeld v. Padilla, 03-1027.

To contact the reporter on this story: Laurie Asseo in Washington at lasseo1@bloomberg.net.

Last Updated: April 20, 2004 09:32 EDT