Both countryballs were recently devastated by the Korean War, which had displaced millions of Koreans and left much of the Korean peninsula completely razed. For much of the following year, neither countryball was in a position to incite another unification attempt by sheer force.
Hostilities can be traced back to the 1960s, as North Koreaball began to increasingly fear South Koreaball's rapid industrial growth, USAball's increasing commitment in the Vietnam War, and the renormalization of relations between South Koreaball and Japanball. North Koreaball began to place increasing emphasis on practicing irregular warfare, agitation, and propaganda.
Blue House Raid (1968)
On the 17th of January 1968, 31 soldiers from Unit 124, a North Korean special operations force, cut through a section of the DMZ barbed wire under the cover of night. Their mission was specifically to infiltrate South Koreaball's clay and assassinate the then-dictator of South Korea, Park Chung-Hee.
2 days later, the soldiers came across 4 woodcutters. Rather than killing them, the soldiers decided to inform the woodcutters about the glories of North Koreaball and Juche. The woodcutters were released after being warned not to alert South Koreaball's authorities, but they notified the police as soon as possible. By the next morning, the police and military were on full alert. The soldiers from Unit 124 disguised themselves as South Korean infantrymen and began to march the last 2 km to the Blue House ( South Koreaball's Presidential Palace). After passing several police units, the soldiers were stopped just a mere 800 meters from the Blue House by a police unit. They were questioned by the suspicious South Korean officers, and one began to draw his pistol before one of the men from Unit 124 shot him preemptively.
A gunbattle immediately ensued as Unit 124 attempted to flee, resulting in the deaths of 2 men from Unit 124. An extensive hunt also followed, and a further 26 men from Unit 124 were killed. 26 South Korean.
Axe Murder Incident (1976)
On the 18th of August 1976, a group of South Korean and American servicemen traveled to the Joint Security Area (JSA) to trim a poplar tree that was obstructing the watchtowers' view. Suddenly, 15 North Korean soldiers appeared and warned the detachment to stop trimming immediately. The detachment ignored their demands.
After being ignored by the request to halt, North Korean Lieutenant Pak dispatched a truck carrying North Korean troops armed with clubs and crowbars. Pak once again demanded the South Koreans and Americans to halt the trimming but was ignored once again. Pak then removed his watch, wrapped it with his handkerchief, placed it in his pocket, then shouted: "Kill those bastards!"
The ensuing attack fatally wounded 2 men and left all but 1 injured.