At the height of the cold war, US forces maintained a hair-trigger alert along a 17-mile fence line to defend the soil of this military base against communist encroachment.
Now, at the height of a different kind of war, US government lawyers are arguing that Guantanamo isn't American at all, that it really belongs to Cuba.
It is more than just an esoteric debate about an open-ended 1903 lease agreement with Cuba establishing Guantanamo as a US coaling station. Rather, it goes to the heart of the Bush administration's effort to convert a portion of this dusty naval base into a terrorist penal colony beyond the reach of US laws and constitutional protections.
Simply put, the issue is whether the naval base is sovereign US territory or a mere piece of rental property with Fidel Castro as the current landlord.
The answer to that will either facilitate or greatly complicate US efforts to detain, question, prosecute and perhaps execute the 300 suspected Taliban and Al Qaeda fighters being held indefinitely at a makeshift detention camp here.
"These people were brought to what we believe to be the territorial jurisdiction of the United States," says Joseph Margulies, a Minneapolis lawyer and Cornell University law professor, who has filed a lawsuit in Washington on behalf of two British men and an Australian being held here. "They are in Guantanamo because the United States brought them to Guantanamo."
What that means from a legal standpoint, Mr. Margulies says, is that the detainees are entitled to the protections and guarantees of the US Constitution including the right not to be held indefinitely without due process of law.
In 1950, the US Supreme Court ruled that foreign nationals outside the sovereign territory of the US are not entitled to key constitutional protections.
So the essential question is whether Guantanamo is sovereign Cuban or sovereign US territory.
Lawyers for the US government say that the 1903 lease agreement addresses the legal status of the naval base with perfect clarity.
The lease reads in part: "While on the one hand the United States recognizes the continuance of the ultimate sovereignty of the Republic of Cuba ... on the other hand the Republic of Cuba consents that ... the United States shall exercise complete jurisdiction and control over and within said area."
Reading the language of the lease, a federal judge in Los Angeles on Feb. 21 dismissed one of the lawsuits filed on behalf of the Guantanamo detainees.
"There is a difference between territorial jurisdiction and sovereignty," writes US District Judge Howard Matz in his decision. "The court finds that Guantanamo Bay is NOT within the sovereign territory of the United States."
Erwin Chemerinsky, a constitutional law professor at the University of Southern California who argued the case before Judge Matz, says he is appealing the judge's decision. "I read Article III of the Guantanamo Treaty as making Guantanamo part of the territory of the United States," he says. In effect, the US exercises de facto sovereignty, he says.
He has a point. US flags fly on the highest hills here not a Cuban flag in sight. You need stamps from the US Postal Service to mail a letter. And if you try to buy a Cuban sandwich with Cuban pesos rather than US dollars, you are going to have to skip lunch.
But is that sovereignty or just absolute control?
David Rivkin, a Washington lawyer and international-law expert, acknowledges that the US exerts unquestioned authority over day-to-day operations at Guantanamo, but that doesn't entitle the US to exercise sovereignty. "Can we sell Guantanamo?" he asks. "No, because it isn't ours."
The issue isn't entirely new. In 1993 and 1994, two federal judges one in New York and one in Miami ruled that Cuban and Haitian refugees intercepted at sea and housed temporarily at Guantanamo were entitled to constitutional rights because the US exerts "complete control and jurisdiction" at Guantanamo.
But the 11th US Circuit Court of Appeals in Atlanta reached a different conclusion, overturning the Miami judge. "We ... reject the argument that our leased military bases abroad which continue under the sovereignty of foreign nations, hostile or friendly, are 'functionally equivalent' to being within the United States," the appeals court ruled in 1995.
What the ruling meant for Cuban and Haitian refugees in Guantanamo at that time was that their mere presence in Guantanamo wasn't enough to trigger legal rights in a US court.
Lawyers for the US government are now making the same argument about the suspected Taliban and Al Qaeda fighters.
In a brief filed in the Los Angeles case, Assistant US Attorney Douglas Axel writes: "These detainees are aliens, and Guantanamo lies outside the sovereign territory of the United States, and so [existing US Supreme Court precedent] precludes jurisdiction in this or any other United States court."
Lawyer Margulies says the 1950 Supreme Court decision on this issue is different in important ways from the Guantanamo situation. It involved the prosecution of suspected German spies in China during World War II. The US military tribunal was conducted in China with the permission of the Chinese government.
"Contrast that with Guantanamo Bay, where we have had exclusive control since 1903. Nobody gets in or out without the permission of the US government," he says. "It has its own power and schools. It is a functioning small city under the complete control of the United States. To say it is equivalent to a foreign country is preposterous."