(CBS) A skeptical federal appeals court Monday questioned whether it has the authority to help detainees in the war on terrorism who have been held for many months, without lawyers and without being charged, at the U.S. naval base in Guantanamo Bay, Cuba.

The United States has been involved in many wars in its history, "but this is the first time we have sacrificed the rule of law," attorney Joe Margulies told judges A. Raymond Randolph, Stephen Williams and Merrick Garland.

Margulies, who represents the families of four British and Australian detainees, argued that courts must step in to restore basic legal rights.

"Because otherwise what you have is the prospect of indefinite arbitrary detention," he said.

Lawyers for the detainees and their families say the Bush administration is stretching the meaning of a half-century-old U.S. Supreme Court case and is denying rights to people picked up in Afghanistan and Pakistan.

"We're trying to fight for the fundamental principles for which our nation was founded," said Tom Wilner, a lawyer arguing for 12 Kuwaiti detainees.
"These are people who don't have access to anyone (and) someone should be able to sue on their behalf."

But the three judges asked a series of questions seeming to cast doubt on whether they can direct the U.S. military to give due process rights to the aliens in Guantanamo.

Williams was appointed during the Reagan administration, Randolph during the first Bush administration, and Garland is a Clinton appointee.

Guantanamo has nearly 600 detainees.

The question is not whether it's a good idea, says CBSNews.com Legal Analyst Andrew Cohen, the question is whether it's legal. Cohen adds that right now the answer is "we don't know." The Supreme Court, for example, hasn't yet weighed in on whether the Administration can detain American citizens indefinitely, without charges and without the ability to see an attorney.

Things will shake out eventually but right now the fact is that no one in the Administration knows how far they'll be able to go in creating this new sort of criminal process, said Cohen. "I think we'll continue to see the Justice Department pushing up against the boundaries of the Constitution and hoping that the courts continue to defer greatly to the Executive Branch."

Deputy Solicitor General Paul Clement said that the Guantanamo detainees are enemy combatants and lack standing in U.S. courts because they are being held outside the United States.

The government is relying on a 1950 Supreme Court ruling involving German nationals in World War II convicted before a military

Like the Germans, the Guantanamo detainees "are 'actual enemies, active in the hostile service of an enemy power"' and they lack standing in U.S. courts, the Justice Department said in recent court papers.

The two cases are completely different, lawyers for the detainees and their families responded.

"It is one thing to acknowledge...that enemy aliens in the active service of a hostile state cannot seek post-conviction relief in the federal courts," they said in a court filing. "But it is quite another to suggest...that any alien...may be deprived of their liberty indefinitely by the United States military, with no legal process, simply by the expedient of bringing them to Guantanamo Bay."

"Congress has never so much as intimated, let alone made a 'plain statement,' that aliens detained outside the 50 states have no right to seek the writ of habeas corpus," the filing said. The appeals court should "recognize Guantanamo Bay for what it is: a fully American enclave with 'the basic attributes of full territorial sovereignty.'"

Cohen says the federal courts are going to have the final say on whether those plans can be implemented under the Constitution. And so far that is very much an open question — not only have these detainee issues not made it to the Supreme Court the lower courts haven't even resolved them yet.

The U.S. military announced late last year that the 45-square-mile base on the southeastern tip of Cuba, the oldest U.S. overseas outpost, was the destination for Taliban and al Qaeda prisoners.

The United States leased the land for the base from Cuba in 1903 for 2,000 gold coins a year, now valued at $4,085. Washington pays that amount every year, but Fidel Castro's government refuses to cash the checks.

The base is surrounded by 17.4 miles of fence line and a corresponding Cuban fence line and minefield.

As for the detainees in the appeals court case:

• The 12 Kuwaitis were in Afghanistan doing charity work and weren't there to fight, their families have said.
  
  
• British Muslims Asif Iqbal, who is in his early 20s, and Shafiq Rasul, who is in his mid-20s, flew to Pakistan and then to Afghanistan just days before the Sept. 11 attacks.
  
  
• There is little doubt that Australian David Hicks, 26, had joined the Taliban when he was captured by U.S.-backed Northern Alliance forces in Afghanistan, Australian Prime Minister John Howard has said. Hicks' family denies that he trained with al Qaeda. Australian newspapers have published photos of Hicks as a freckled 10-year-old schoolboy alongside a picture of him as a bazooka-toting soldier taken during a stint in Kosovo, where he fought with Muslims in the Kosovo Liberation Army.
  
  
• Australian Mamdouh Habib, 47, was captured by U.S. forces in Pakistan on suspicion of links to al Qaeda. Habib's wife denies any al Qaeda connection. The couple have four children.

Habib's Sydney-based attorney, Stephen Hopper, told Australian television that Habib, who also holds Egyptian citizenship, visited New York in 1991 and met a man who later was convicted in the 1993 World Trade Center bombing. Subsequently, another man convicted in the 1993 bombing called Habib in Australia a couple of times trying to get him to raise money for his defense, Hopper said.

The other Guantanamo prisoners are from more than 40 countries and include about 60 Pakistanis and some 100 Saudi Arabians. A handful of Afghan and Pakistani detainees have been sent home from Guantanamo after being cleared of terrorist suspicions.