What if there was another world?

I'll use latin america as an example because it is by comparison to other countries relativley new to the world stage. If the Latin American countries decided all together by some sort of epiphany or whatever to separate entirely from the rest of the world. They got rid of all foreign companies, and created their own economy souly for them. They become kind of like shut ins. They are a very resource rich part of the world after all and they take their resources and what they know in terms of science, government, etc etc. and just created another world. They would not comunicate with any other country but eachother. My question is would the U.S. and other countries have a problem with that and what actions would the other countries take to either prevent it or stop it. A strictly hypothetical question originating from curiousity.