Because the US trade embargo, aimed at the Communist regime of Fidel Castro, requires the people of Cuba to live on short rations of everything, they can no longer perform the Cuban dance called the cha-cha. The best they can do is the cha. Anti-Castro Cuban emigres in Miami, Florida, have been gloatingly dancing the cha-cha-cha and even the cha-cha-cha-cha.