Guantánamo Bay Naval Base at the southeastern end of Cuba has been used by the United States Navy for more than a century, and is the oldest overseas U.S. Navy Base and the only one in a country with which the United States does not have diplomatic relations. The United States controls the land on both sides of the southern part of Guantánamo Bay (Bahía de Guantánamo in Spanish) under a lease set up in the wake of the 1898Spanish-American War. The lease was established in a 1903 agreement between the two governments, and its terms were modified in a 1934 treaty. The current Cuban government considers the U.S. presence in Guantánamo to be an illegal occupation of the area, and argues that the Cuban-American Treaty, which established the lease in 1903, now violates article 52 of the 1969Vienna Convention on the Law of Treaties, though the issue is still open to argument. However, Article 4 of the same document states that Vienna Convention on the Law of Treaties shall not be retroactively applied to any treaties made before itself.
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