South Korea, like many countries, has a mandatory military service period for males between the ages of 18 and 35. You may remember last year when South Korean singer, actor, and model Rain made news upon giving his mandatory service. The period is about two years, but varies for the particular military branch. Army and Marine Corps enlistees serve a 21 month minimum, Navy enlistees serve 23 months, and Air Force enlistees serve a full 2 years.
Generally speaking, there isn’t much that would get someone out of serving- except for a gold medal. Sports athletes who win gold medals in the Olympic Games, the Asiad, or other notable sporting events are exempt and only have to complete four weeks of training. The Asiad is a multi-sport event similar to the Olympics held every four years in Asia.
Officially, the games are organized by the Olympic Council of Asia and recognized by the International Olympic Committee. Behind the Olympics, these games make up the largest multi-sport event in the world.