The Hakkens are accused of kidnapping their young sons from the custody of Sharyn's parents and sailing with them and his wife to Havana. Cuba promptly informed the State Department of the couple's weekend arrival on the island, and worked with U.S. officials to send the family home swiftly.
Both sides praised the joint effort.
"We would like to express our appreciation to the Cuban authorities for their extensive cooperation to resolve this dangerous situation quickly," the U.S. Interests Section in Havana, which Washington maintains instead of an embassy, wrote in a Wednesday statement.
In Washington, State Department spokesman Patrick Ventrell termed cooperation as "extensive," but said the case should not be taken as a sign of political opening.
"I'm not sure I would read into it one way or another," he said. "This was cooperation on a specific law enforcement matter."
Diplomats agree, and point to less dramatic examples of cooperation as more germane.
U.S. and Cuban diplomats must get authorization to travel outside each other's capitals, something that was once used as a cudgel by both sides to get revenge for political slights. Lately, they say, permission has been granted on an almost routine basis.
American diplomats have travelled increasingly throughout the island, for work and play. For its part, Cuba's top envoy in Washington, Jose Cabanas, recently visited Georgia, Houston and New Orleans, among other places.
At times, diplomatic cooperation has reached levels that would be surprising even between friendly nations.
During last month's World Baseball Classic, a U.S. Interests Section official personally carried emergency visas for several Cuban coaches and support staff on a trip to Guam and handed them off to a Tokyo-based colleague, a U.S. official told AP. At the time, Cuba was playing its early round games in Japan and would have needed the visas if the team had advanced to the semifinals in San Francisco.
Several weeks ago, U.S. Consul General Timothy Roche spoke with Cuba's Communist Party daily Granma about American immigration policy, believed to be the first time in 10 years that state-media carried such an interview with U.S. diplomatic staff.
Even on thornier issues like the U.S. naval base at Guantanamo Bay — which Cuba has denounced as a torture camp — the two militaries hold occasional joint exercises to prepare for brush fires and other emergencies.
Jorge Pinon, a leading expert on Cuba's oil industry and research fellow at the University of Texas, said American and Cuban energy and environmental officials have for years worked past the political morass and established strong working bonds.
When politics allows, he said, those ties could be the basis for something bigger.
"Just like ping pong opened China and the U.S. relationship," Pinon said. "The environment, working on drugs and other subjects of common interest could certainly be those bridges which will make us trust each other and be able to have a civil conversation on other topics."
Associated Press writers Peter Orsi and Andrea Rodriguez contributed.
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