After the successful revolution in the Latin American countries, instead of democracies as the people wanted, the countries became mostly communist and dictatorships. While in some countries that communism was embraced by the people, and in the case of Cuba it worked out relatively well, it was not the case for most of the other countries. The other nations were stuck with dictators that tried to control every aspect of the country and society, and they did it in a very bad manner, usually using violence. That was not seen fondly by the people, so there were lot of conflicts, which eventually led to the overthrow of most of these leaders, and finally became democracies, at least on paper.
