The US pays the Cuban government $4,085 annually in rent for the 45-square-mile naval base at Guantanamo Bay. Sort of.

For more than 50 years, Cuba has refused to cash the checks because it hasn't recognized the legitimacy of the lease the US entered into with the country in 1901, which the Cuban Constitution says gives the US "complete jurisdiction and control" over Guantanamo. (The US Treasury sends the checks through the Swiss embassy, which represents US interests in Havana.)

Now, with today's historic announcement by President Barack Obama that relations between the US and Cuba are on the mend, there are questions about whether Guantanamo came up during the discussions between Obama and Cuban President Raul Castro.

Spokespeople for the White House and State Department did not respond to requests for comment.

State Department documents that include copies of uncashed rent checks — they were recently released in response to a Freedom of Information Act (FOIA) request (pdf below) — say the US is technically in default of its lease agreement with Cuba, which states that Guantanamo is "to be used only for a coaling station [a place to refuel Navy vessels]."

On April 26, 2006, Timothy Zuniga-Brown, a State Department diplomat, sent an email to Thomas Gerth, a senior adviser to the State Department's Office of Cuban Affairs, asking him to confirm information and questions he was sent "regarding the status of the lease over Guantanamo." Zuniga-Brown — the bolding in the email is his — was concerned "some of the wording here sound[ed] a little loose":

Cuba's constitution, which was adopted in 1901, included what is called the Platt Amendment, legislation that established conditions for American intervention in Cuba and gave the United States the right to maintain a military base on the island in perpetuity. The lease contains several critical provisions relevant to whether U.S. courts have jurisdiction over the base. First, the lease gives the United States "complete jurisdiction and control" of that territory, saying merely that it "recognizes the continuance of the ultimate sovereignty of the Republic of Cuba." Secondly, the lease can only be terminated on the mutual consent of both parties. Even though Cuba has wanted to terminate the lease since the revolution of 1959, it is unable to do so without the consent of the United States. The lease actually provides for a miniscule rent, some two thousand dollars in gold (equivalent to about $4,085 a year in current U.S dollars), although the Cuban government has refused to accept any payment since 1959. The United States is technically in default, and has been for many years, because the lease provides that the base is to be used only for a coaling station.

In other words, the 136 detainees currently imprisoned on the island would technically be a violation of the lease agreement. In December 2001, then-Secretary of Defense Donald Rumsfeld explained why the Bush administration chose to build a detention facility there.

"I would characterize Guantanamo Bay, Cuba, as the least worst place we could have selected," Rumsfeld said during a December 27, 2001 press briefing. "It has disadvantages…. Its disadvantages, however, seem to be modest relative to the alternatives."

Rumsfeld did not reveal that a young Justice Department attorney named John Yoo had just finished writing a legal memo that he sent to Pentagon General Counsel William "Jim" Haynes a day later that said Guantanamo was the perfect location because it was outside the law and it was unlikely US courts would grant detainees there habeas corpus rights.

Bush administration officials had at one point considered detaining prisoners in Guam, but Justice Department lawyers determined that detainees would be able to challenge their detention in US courts because, as Joseph Hansen wrote in Guantanamo: An American History, Guam would not be immune from federal court oversight and could be accessed by lawyers and journalists

Yoo's analysis was ultimately proved wrong a decade later when the US Supreme Court issued a landmark ruling in Boumediene v. Bush granting Guantanamo detainees habeas corpus rights.

VICE News also obtained State Department documents that show members of Congress had been lobbying the State Department over the past year calling for Obama's national security staff to review Cuba's 1982 designation as a state sponsor of terrorism.

"At this time, the Department has no existing plans to remove Cuba from the State Sponsor of Terrorism list," the State Department's Acting Assistant Secretary of Legislative Affairs, Thomas Gibbons, wrote in a June 17, 2013 email to Sen. Carl Levin, the chairman of the Senate Armed Services Committee.

In a press briefing Wednesday, Obama said he has instructed Secretary of State John Kerry to review Cuba's designation as a State Sponsor of Terrorism.

"This review will be guided by the facts and the law," Obama said. "Terrorism has changed in the last several decades. At a time when we are focused on threats from al Qaeda to ISIL, a nation that meets our conditions and renounces the use of terrorism should not face this sanction."