After the Ruling, Impact on Guantanamo Prisoners

For the roughly 450 men currently being held at Guantanamo Bay, today's landmark Supreme Court ruling is likely to have little immediate impact on their daily lives, although the biggest effect could be on the interrogation practices used at the military prison.

Watch "Nightline" for more of anchor Terry Moran's report from the detainment camp in the prison at Guantanamo Bay.

The most immediate impact is on Salim Ahmed Hamdan and the other nine men charged with war crimes who are scheduled to be tried before a military commission.

The Supreme Court ruled the Bush administration must come up with another system for these cases, stating that the use of military trials would be illegal under U.S. and international law.

"If they are prosecuted at all, there will be a number of due process rights that are afforded to them now that would not have been afforded to them before … but that's going to make the cases harder to prosecute," said John Hutson, president and dean of the University of New Hampshire's Franklin Pierce Law Center.

Prisoner Treatment in Question

Prisoners are confined to wire-mesh cells and have regimented hours of exercise, conditions that one lawyer called a sleeping giant in today's ruling, declaring the United States must abide by the Geneva Conventions in dealing with al Qaeda prisoners. It's a position President Bush rejected in 2001, sparking international controversy.

"The treatment of the prisoners must meet the standards of humaneness that is called for by those conventions," said Prof. Walter Dellinger of the Duke University Law School.

The biggest impact of the ruling could be on the interrogation practices. Today, we visited the section of the camp where detainees meet with their lawyers and are shackled to the floor during sessions.

The Geneva Conventions not only prohibit "cruel treatment and torture," but they also ban "humiliating and degrading treatment," techniques that in the past have been expressly permitted by the Pentagon and used at Guantanamo.

The military prison's director of interrogation, Paul Rester, told ABC News such practices are now banned at Guantanamo. When asked if the United States has humiliated a detainee by making him wear women's underwear, as has been alleged, Rester responded, "No."

"It's alleged and was investigated," Rester said. "[I] didn't see it, didn't witness it. Would I permit it? No. Does it happen? No."

Authorities at Guantanamo have had no official response to the the Supreme Court ruling, and are still trying to assess how it will affect the future for these inmates.