People line up outside the U.S. Interests Section in Havana to apply for visas. (YAMIL LAGE/AFP/Getty Images)

The top American diplomat at the U.S. Interests Section in Havana lives in high style, in a 32,000-square-foot mansion on five acres with a swimming pool, tennis courts and its own supply of water and electricity. The windows provide a view of sun-drenched gardens and stately imperial palms.

“It is one of the grandest diplomatic residences we have in our inventory,” said John Caulfield, who lived there as chief of mission from 2011 until last year.

And yet, from the balcony of the World War II-era residence, which also housed the U.S. ambassador before diplomatic relations with Cuba were severed in 1961, Vicki Huddleston, another former resident, could see the telescope in a neighbor’s window that tracked her movements. She assumed that her home was bugged and videotaped — a neighboring house, after all, was used by Fidel Castro and the Cuban military. James Cason, who was chief of mission from 2002 to 2005, recalled how the maids and drivers on his house staff, all Cuban government employees, would tell him when they had to inform their superiors about him.

“They’d say, ‘I’ve got to go rat you out now,’ ” he recalled. “I would say, ‘Tell them we’re meeting the dissidents!’ ”

Such are the oddities of daily life as a U.S. diplomat in Cuba, a tropical paradise that has also been, for the past half-century, enemy territory. Last month, President Obama announced his intention to normalize relations with Cuba, replacing the Interests Section with an embassy and promoting the chief of mission to ambassador. If the president accomplishes that, it probably wouldn’t stop the spying but it would bring to a close a bizarre chapter in U.S. diplomatic history.

“You’re clearly the enemy,” Huddleston said. “But not really the enemy.”

To work in the Interests Section in Havana, a boxy seaside office building that served as the embassy, then reopened in 1977 during the Carter administration, is to see geopolitics writ small.

U.S. diplomats must ask for permission and give two weeks’ notice if they want to travel outside Havana, just as Cuban diplomats in Washington are banned from venturing beyond the Beltway without approval. Cuban diplomats declined to comment for this story.

The Interests Section in Havana has about 360 staff members, but the U.S. contingent is limited to 51, including Marine guards. Cubans hired from a government employment agency make up the rest. Because of concerns about espionage, those Cuban employees are confined to the first two floors, where no classified information is discussed.

The building cannot fly the American flag, nor can the chief of mission, currently Jeffrey DeLaurentis, put one on his car. Arriving mail is scrutinized; a package sent from Miami can take months to reach diplomats in Havana, even though the flight takes less than an hour. One diplomat received a Christmas card last week that was sent Sept. 23.

Exposed to the salty ocean air, the Interests Section building has taken a beating over time, and it’s tough to find people and equipment for repairs. The building is crowded and short on conference rooms. Staffers cover the worn spots on their cubicle dividers with posters.

More than 50 years after the U.S.-imposed embargo, President Obama has announced an effort to normalize ties with Cuba.

Caulfield took over the mission in 2011, when tensions had easeda bit, but sometimes fixes required creativity. Once, he needed a crane to install an air-conditioning unit on the roof and finally had to buttonhole a senior Cuban official at an event before his request was approved.

“We spent a long time trying to get permission for that crane,” he said.

Occasional flare-ups

Over the years, the background tensions have occasionally flared into open confrontations. During the saga of Elián González, the Cuban boy whose mother drowned in 2000 while trying to take him to Miami and whose father wanted him back in Cuba, Castro led marches in Havana demanding the boy’s return. Castro had an area outside the chancery converted into an “open court” and amphitheater where the United States could be publicly condemned.

In a move to “protect” the Interests Section, the Cuban leader sent schoolchildren to ring the American building, hand in hand, during one protest. “It was amazing,” recalled Huddleston, who arrived in Havana in 1999. “We looked like we were this evil Goliath.”

On another occasion, Huddleston raised the ire of the Cubans when her Afghan hound, Havana, started winning prizes at dog shows in Cuba. She received a letter from the national Afghan hound kennel club banning her from participation due to the U.S. “policy of hostility against our people and our government.” Huddleston took to the news media with every bad pun she could think of.

“I really played it up: ‘We’re in the doghouse again. We’re on a short leash,’ ” she recalled.

The most provocative recent chief of mission has been Cason, who followed Huddleston in the early years of the George W. Bush administration. Now the mayor of Coral Gables, Fla., Cason said he traveled 7,000 miles around the island in the first three months he was there, meeting with dissidents and distributing books and radios until the Cuban government banned him from traveling outside the capital.

Cason had a giant news-ticker installed on the outside wall of the Interests Section showing headlines from abroad and criticism of the Cuban government. The Castro government responded by erecting dozens of black flags to block the screen. In July 2005, before he departed, Cason unveiled a three-story-high metal Statue of Liberty with lights that formed “75” — the number of dissidents rounded up a couple of years earlier.

Cason said he was allowed to meet only one Cuban government official, the director of North American affairs in the Foreign Ministry.

His successors, including Caulfield, tried to keep a lower profile.

But suspicions about U.S. intentions lingered, decades after the CIA had tried to kill Castro with exploding cigars or a tuberculosis-laced wetsuit. The American diplomats believed their homes and cars were all bugged, as well as restaurants they frequented. Cuban police ringed the Interests Section.

“There was a lot of harassment,” Caulfield said. “We were intensely followed everywhere, physically, electronically. There’s no privacy in Cuba for U.S. diplomats.”

But this scrutiny waxed and waned with shifts in relations. Caulfield said he noticed the restrictions easing substantially halfway through his posting there as cooperation between the governments increased on issues such as immigration, civil aviation, and environmental protection. The Cubans and Americans have also cooperated on aspects of drug enforcement and the U.S. military prison at Guantanamo Bay.

Planning for the future

When Roberta Jacobson, an assistant secretary of state, visits Havana this month , she is expected to start discussions on reopening embassies in both countries, including issues such as caps on diplomats and travel restrictions. U.S. officials expect that they will use the same Interests Section building but with a new plaque declaring it an embassy.Diplomats for both countries will probably continue to be watched closely, and the economic embargo will remain in place unless lifted by Congress, but many expect that small changes could go a long way.

“It will be hugely symbolic,” Huddleston said — for Americans but also for the Cuban people. “We’re no longer, for lack of a better word, your enemy. We want to see you progress. We want to see a more normal relationship.”