1903 Article III: "That the government of Cuba consents that the United States may exercise the right to intervene for the preservation of the Cuban independence, the maintenance of a government adequate for the protection of life, property, and individual liberty, and for discharging the obligations with respect to Cuba imposed by the treaty of Paris on the United States, now to be assumed and undertaken by the government of Cuba."
The US interprets the 1903 Article III to mean that the Cuban government gives consent, in advance, for interventions that otherwise, without consent, would be a violation of Cuban self-government, which self-government was transferred to the Cuban people via the Treaty of Paris and because the Teller Amendment kept the US from outright seizure of Cuba. This placed Cuba under the benevolent eye of the United States.
1934 Article I: "The treaty of Relations which was concluded between the two contracting parties on May 22, 1903, shall cease to be in force, and is abrogated, from the date on which the present Treaty goes into effect."
1934 Article I cancels 1903 Article III, which granted blanket consent to intervention, yet the United States, through boycotts, quarantines, blockades, over-flights, invasion, and black operations, continues to act as though 1903 Article III were in effect, and pushes aside 1934 Article I. That makes these actions unfriendly, and a material and fundamental breach of the Treaty of 1934. They render that Treaty void, because they run counter to international expectations that promises must be kept, and constitute an unexpected substantial change to the underlying conditions, in that the Unites States no longer seeks the maintenance of the government of Cuba, but its destruction.
This abrogation of the Treaty of 1934 on the part of the United States was matched by the equally hostile action of the invitation to the Russians by the Cubans to install nuclear weapons on its soil, something permitted by treaty, but an act that responded to the change in the underlying situation, and created further unexpected changes to the underlying situation.
Therefore, the Treaty of 1934 is voidable.
Since only the Treaty of 1934 addresses the question of the termination of the lease, the issue of lease termination is unspecified, other than the standard conditions.