Even the US does not claim to "own" Guantanamo. It has a LEASE on it, and the payment for that lease has been refused for the past 57 years,
No lessee is an owner.
So what is the complaint?
The lease is as old as Cuba's nation itself, and for more than half that time was a major employer to the locals there.
As a matter of fact , most of the time that Fidel has been monarch this base was opening its gates to let in the local workers who worked there, they would surrender most of their pay on their return trip come payday.
I suppose that we need to leave there about the same as we need to leave Okinawa , but I don't expect a big money savings from either .
When we left those massive bases behind in the Philippines, did it save money?