United States embargo against Cuba
The embargo applies to American businesses, and also it applies to businesses owed by other countries who have business in the USA. The effect is that the embargo stops trading with Cuban interests.
It is the longest enduring trade embargo in modern history. The United States first imposed an embargo on the sale of arms to Cuba on March 14, 1958, during the Fulgencio Batista regime. Again on October 19, 1960 (almost two years after the Cuban Revolution had led to the deposition of the Batista regime) the U.S. placed an embargo on exports to Cuba except for food and medicine. This was because Cuba nationalized American-owned Cuban oil refineries without compensation. On February 7, 1962 the embargo was extended to include almost all exports. Since the year 2000, the embargo no longer prohibits the trade of food and humanitarian supplies.
The stated purpose of the Cuban Democracy Act of 1992 is to keep sanctions on Cuba as long as the Cuban government refuses to move toward "democratization and greater respect for human rights".