The 1903 lease documents have no clauses that give a termination date for the lease. The motivation for the lease is mutual protection, and the method is Naval and Coaling Stations.
The motivation has been abandoned, and the means are obsolete.
1. No longer necessary as a coaling station
2. No longer necessary as a Naval Station for the mutual defense of the US and Cuba
The lease may be terminated for the reasons that a contract may be terminated, since a lease is a contract.
1. Material breach
Building a prison is a material breach
2. Anticipatory Breach
Kennedy's promise to not invade Cuba is an anticipatory breach of the US's duty to protect Cuban independence.