South Korea is a country.
This article includes a list of countries by their forecasted estimated gross domestic product ( PPP ) . This article is a list of countries by military expenditure in a given year . This is a list of countries by research and development ( R&D ) spending in real terms and as per latest data available . South Korea , officially the Republic of Korea ( ROK ; ) , is a sovereign state in East Asia , constituting the southern part of the Korean Peninsula . It has free trade agreements with 75 % of the world economy and is the only G20 nation trading freely with China , the US and the EU simultaneously .