There are several perspectives on the nature of the Vietnam War and reasons of dispatch of Korean troops in Korean society. It is the disagreement between the war for the liberal defence against communism and Vietnamese national liberation. As we see the Vietnam War which was escalated into hot war since 1964, thanks to the abrogation of the 1954 Geneva Agreement, we cannot deny that it is the national liberation war. It is still controversial on reasons why Korean government dispatched troops into Vietnam. Though researchers have argued that its reasons were reward for the American effort to defend Korea during the Korean War, America's enforcement to dispatch, substitutive dispatch instead of US troops in Korea, political and economic interest so far, it is still controversial which one is the main reason. Nevertheless, Korean government tried to maximize its political and economic gains and got impacts on stabilization of the regime and economic growth. We still have unresolved issues concerned with the Vietnam War. They are Korean veterans' physical or mental injury, missing in action, and massacre of Vietnamese civilians. In the relationship between Korea and Vietnam, both sides have already step up their fraternal relationship. If there is historical fault, we should not cover it, but try to overcome it for the enhancement of relationship between Korea and Vietnam.