Yanqui, Go Home

The US occupies Guantanamo without a legal basis.
The lease contract for Southern Guantanamo Bay, negotiated in 1903, after the Spanish American War, is no longer valid, if it ever was valid. When President Teddy Roosevelt signed the lease, the US and Cuba were military allies and the President was a decorated veteran of the war for Cuban Independence.

The first paragraph of the lease, labelled "AGREEMENT"[1] repeats the obligation, imposed on the United States by the Treaty of Paris, “To enable the United States to maintain the independence of Cuba, and to protect the people thereof, as well as for [the Cuban Government’s] own defense…”. The United States has refused to protect Cuba, its independence, and continues to try to dominate Cuba. This is a material breach of contract, and allows Cuba to repudiate the lease, which Cuba does each year by not cashing the check that the US sends to Cuba. The fact that the US sends a check to the communist government in Cuba is a recognition that the communist government in Cuba is the government to which the obligations of the lease are due, including the obligation to protect.

For more, see this.