Should the United States go back to the good old days?

Well I have an idea let’s go back to the America of old. It was called isolationism. That way all our troop's come home. We quit the United Nations and if your country is hit by famine or a typhoon don't call us we don't care. Don’t forget to close all our borders too. Put our military on the boarders with Mexico and Canada. Think of the money we would have if we would quit sending it all over the world to help all the countries that tend to hate us any ways. Well it’s just a thought. America might not be perfect but it is still the greatest country in the world. You do have a choice if you don't like living here you can always move to another country.