In foreign policy , ties with Japan were strengthened by state visits by Chun to Japan and Japanese Prime Minister Yasuhiro Nakasone to Korea . U.S. President Ronald Reagan also paid a visit , and relations with the Soviet Union and China improved . The relationship with North Korea was strained when in 1983 a terrorist bomb attack in Burma killed 17 high-ranking officials attending memorial ceremonies and North Korea was alleged to be behind the attacks . However , in 1980 North Korea had submitted a " one nation , two system " reunification proposal which was met with a suggestion from the South to meet and prepare a unification constitution and government through a referendum . The humanitarian issue of reuniting separated families was dealt with first , and in September 1985 , families from both sides of the border made cross visits to Seoul and Pyongyang in an historic event
a terrorist bomb attack in Burma
Rangoon bombing
History of South Korea