Cuba's rights to self defense

With the abrogation in 1934 of the May 1903 Treaty of Relations, Cuba became free to enter into military arrangements with any nation for the purpose of securing its independence. The 1963 blockade of Cuba by the USA was intended to frustrate this purpose, which purpose was the benefit to Cuba to be secured by the 1903 lease, according to Article VII of the Appendix to the Constitution of Cuba, which was incorporated into the lease agreement.

The blockade was a fundamental breach.