A guard tower of Camp Delta in Guantanamo Bay. Photo / Reuters

A guard tower of Camp Delta in Guantanamo Bay. Photo / Reuters

Guantanamo Bay, the only United States military base in a country that has no diplomatic relations with Washington, is a concentrated slice of Americana: the Star Spangled Banner blares from loudspeakers every morning as soldiers outside Starbucks stand at attention.

US law protects endangered iguanas on the naval base, but the Supreme Court is struggling to determine whether it also applies to the 305 men imprisoned there.

In the balance hangs America's traditional reputation for justice for all.

Leased by Cuba to the United States 104 years ago under an agreement that can be broken only by mutual consent, the base is firmly in Washington's hands, much to Fidel Castro's annoyance.

Washington pays US$4085 ($5332) a year in rent for the 11,700ha of cactus-studded hills and pristine deep-water bay, but Castro refuses to cash the cheques and recently said the US is illegally occupying the base and using it for "dirty work".

Guantanamo still has a foot in the Cold War - echoes of which are heard when large rodents set off land mines planted in case of communist invasion - but it is also at the centre of the Bush Administration's "war on terror".

The Supreme Court heard arguments last week on what legal protections detainees should be entitled to. The question is surprisingly complicated.

After 9/11, the Bush Administration considered Guantanamo the perfect place to keep men suspected of links to the Taleban and al Qaeda, contending that the host country's laws do not apply and - since it is not part of the US - neither do America's. The first detainees arrived in January 2002.

Lawyers for the detainees have challenged that interpretation ever since.

"No other law applies," lawyer Seth Waxman told the Supreme Court. "If our law doesn't apply, it is a law-free zone."

Detainees' lawyers and human rights groups also argue that military hearings are stacked against the prisoners and are no substitute for regular court proceedings.

Supreme Court justices were intrigued by Guantanamo Bay's unique status. Chief Justice John Roberts asked how Cuban laws apply on Guantanamo, specifically to three elderly Cuban workers who have commuted to work at the base since before Cuba's 1959 revolution.

"If you have two of those workers and they get into a fight over something, one can't sue the other in Cuban courts?" he asked Waxman.