Czechoslovakia
Austria-Hungary
no
Any peaceful country can become a member of United Nations. A country's secretary of state or minister of foreign affairs must contact the UN in New York City for the details.
No, they are two different sovereign nations separated by the 38th parallel.
United Nations Committee on the Peaceful Uses of Outer Space was created in 1959.
Interdependence among nations may not make the world much peaceful. Even with interdependence, you will still have nations interested in exploiting other nations.
detente
United Nations
League of Nations
by the use of economic nations
by the use of economic nations