Essentially, the conflict began after the Second world war.
The Japanese had occupied the country until 1945, when the Soviet Union declared war. The North was given over to the Russians and the area south of the 38th parallel was occupied by U.S. forces.

The country of Korea has been invaded so many times in its 1000 year history. When the north of the country was taken over by the communists from China, the Americans were terrified that communism would spread to the south as well. Ever since the end of the Second World War, South Korea has been ruled by a right wing government and the North has been in the hands of a Communist leader.
A dividing line was established at the 38th parallel (so called because that is the latitude at which it was established). In 1950, only five years after the Second world war ended, the Communist north, led by Kim Il-sung and backed by the Chinese and the Russians, began an invasion in the South.
The war lasted for three years and saw some of the most heroic fighting of any war. In many ways it was fought by outside interests and the Koreans were merely a pawn in the game of the Americans and the Russians. There is a saying that when you are a shrimp amongst whales you will soon be crushed. Korea has the misfortune of being situated next to three larger countries (Japan, China and Japan) which have all sought to establish dominance through the countries’ history.
When the war was ended in 1953, all Koreans living in the north of the 38th Parallel were cut off from the south. Even family members were included. There is a bridge in the DMZ; those who walked into the North of the country must have known that they would never be able to return.
One thing that strikes people as interesting is why the United States did not simply occupy all of North Korea and rejoin the the two regions to form a united Korea, thus saving many ordonary North Koreans a life of extremely bitter hardship and suffering. Unfortunatley, doing so would have caused an even greater loss of life and perhaps could only have come about through the use of an atomic bomb.
The situation today is effectively a military stalemate. The demilitarized zone is heavily guarded by soldiers from the north and south. There are 16,000 American soldiers stationed in the area. It’s said if the Americans would ever leave, the North Koreans would launch another invasion.
Earlier this year there were rocket strikes launced on South Korea in retaliation to what the North saw as attempts to broadcast propaganda over loudspeakers.
Whilst relations between the two countries have been continually hostile, there have been recent attempts made by high profile politicians to reach out to the North Korean regime.
Will the two countries ever be reunited? It seems absurd that two countries with the same language and the same ethnicity should be in such a state of hostility. Unfortunately, the North Korean regime exerts such a stranglehold that they barely have any chance to see what life is like outside the regime.
It is said what will reunite the two countries will not be any diplomatic efforts but will result from widepsread exposure to South Korean television dramas and films. Already, reports are surfacing of ordinary North Koreans gaining an idea of what life is like South of the border. The spread of films will utltimately undermine the leadership of the Kims. Whether it happens in 10, 20 or 100 years, the corrupt leadership will surely one day fall.