Korea
From Halopedia, the Halo wiki
Korea is a country in Northeastern Asia situated on the Korean Peninsula on Earth.
Korea used to be divided into two countries, North Korea and South Korea. This division is not only marked by a DMZ, but a river and hundreds of unknown land mines. It is speculated that the two countries have came back to form Korea once again. Their capitals are Pyongyang (Northern Korea) and Seoul (Southern Korea). Early in the 20th Century Japan took over Korea and ruled it until 1945 when Korea acheived independence. Korea has always been a research powerhouse due to its size and location. It is speculated that it is because of this, and its large gaming community that it was included in the Halo canon.
United Nations Space Command
The UNSC has a number of locations in Korea, namely, the Special Warfare Center in Songnam, Kyonggi Province. This is where the MJOLNIR Mark VI was tested before it was sent to Cairo Station for use by SPARTAN-117.