Here's Why Relations Between North & South Korea Have Been So Incredibly Tense

This year, there have been historic improvements in the relationship between North Korea and South Korea, with the two countries' leaders coming together for a landmark meeting in late April. Now, as President Trump prepares for his own historic meeting with North Korea in June, you may be wondering why exactly North and South Korea don't get along in the first place. As it turns out, it has a lot to do with external powers meddling in Korean affairs.

The tension on the Korean peninsula dates all the way back to the end of World War II and the beginning of the Cold War. Prior to World War II, Korea was one country, though it had been annexed by Japan in 1910. In 1945, as part of a strategy to force Japan to surrender in World War II, the Soviet Army and its related affiliates established a communist government in the northern part of the then-unified Korean peninsula. The government was established in the part of the country that was above the 38˚N latitude line, otherwise known as the 38th parallel.

As part of this same anti-Japan strategy, a military government supported by the United States was formed in the part of the country below the 38th parallel. This government was decidedly anti-communist in nature. While the United States and the Soviet Union, who were allies during WWII, had initially sought to eventually create a unified, independent Korea post-WWII, increasing tensions between the Soviet Union and the United States meant things turned out differently.

Indeed, the Cold War between the Soviet Union and the United States, which lasted from 1947-1991, meant that neither country wanted to lose influence abroad — with both countries seeking to create and/or support other countries that aligned with their own governance doctrines and value systems. The division on the Korean peninsula, which was originally orchestrated by the Soviet Union and the United States, epitomized this tension — and meant that reunification of the country became increasingly unlikely, particularly as the Cold War dragged on.

In 1948, North and South Korea officially formed their own governments, after the North refused to participate in a vote regarding the future of Korea. The government installed in the North was lead by a communist guerrilla and the North became the Democratic People’s Republic of Korea. The government established in Seoul in the South was led by a concertedly anti-communist leader. As Vox reported, both the Northern and Southern governments claimed (and still claim) to be the legitimate government of all of the Korean peninsula — and neither one considered the border division at the 38th parallel permanent.

Unsurprisingly, this led to significant tension on the Korean peninsula, which ultimately resulted in war. In 1950, the North invaded the South, initiating what would become three years of warfare. The United States and the Soviet Union supported the South and North respectively during the Korean War. In 1953, the two Koreas signed an armistice, which established the Korean Demilitarized Zone — an official border area between the two countries. The armistice officially separated the North and the South. However, the countries never signed a peace agreement officially ending the war.

Since the Korean War, the two countries have taken vastly different paths, but tension on the peninsula has remained significant. Indeed, as Straits Times reported, since the conclusion of the war, there have been numerous "attacks, troop infiltrations and clashes" between the two Koreas. Moreover, North Korea became increasingly isolated from the world, with North Koreans living under a regimented dictatorship while the country also focused on pursuing nuclear ambitions to help it secure power on the world stage. For its part, South Korea became a democratic republic and increasingly aligned with countries in the West.

The ongoing tension derived from a never-technically-ended war coupled with the stark differences between the two Koreas means the countries have not gotten along for quite some time. However, things seem to be changing a bit this year. In April, North Korea's leader, Kim Jong Un, met with South Korea's president, Moon Jae-in, becoming the first-ever North Korean leader to enter South Korean territory since the end of the Korean War. Moreover, following their meeting, the leaders issued a historic joint statement declaring they would install a "permanent" and "solid" peace on the Korean peninsula and officially end the war. They also promised to work toward "complete denuclearization."

It remains to be seen whether the promises made by the leaders of North and South Korea will come to fruition. When President Trump meets with Kim in June, he is expected to further flesh out the details of the plan for the future of the Korean peninsula.