Nicaragua, Cuba and Grenada.This paper discusses the meaning of revolution and why the Marxist revolutions in Nicaragua, Cuba and Grenada failed. The paper argues that a revolution promotes the advances of productivity and of the society in general. There are also fundamental changes in political and economic structure. In the case of Nicaragua, Cuba and Grenada, there were major changes, but the lack of economic and political freedom, in combination with U.S. pressure, made it impossible for those revolutions to succeed. 9 pgs. Bibliography lists 11 sources.