The United States can't keep a completely open system if the rest of the world is less open. The United States may have to take a leaf out of the book of Japan, China, and Germany, and have protectionism inside the system.
If you have a rigidly controlled economy, cut off from the rest of the world by infinite protection, nobody has any incentive to increase productivity and to bring new ideas.
A closed country is a dying country.
The problem we were struggling with within the closed market was what the incentive would be. You probably wouldn't use dollars. But those are all questions that need to be explored.
When America closes its doors, so does everybody else.
Despite its increased dependence on the international economy, America continues to behave as if it were either a closed economy or the leader whom everyone else should automatically follow.
As a consequence [of a closed economic circle], in 1912 there was not a single Irishman who sat on a single board of a major Boston bank.
After all, for mankind as a whole there are no exports. We did not start developing by obtaining foreign exchange from Mars or the moon. Mankind is a closed society.