Cuba has undergone a great amount of economic and political turmoil, not only domestically but also in its relations with its neighbors and other countries. While still a communist country, certain reforms have been made. The Cuban Constitution was amended in 1991 and all references to Marxism and Leninism were removed. Cuban citizens were allowed to own and use U.S. dollars after 1993 and be self employed. And as from 1996, foreign companies were permitted to purchase real estate and operate their business on the island. This has helped Cuba’s economy. Ties with the U.S. remain frozen, with the latter still upholding sanctions against the island.