Korea's Demilitarized Zone

At 4 a.m. on June 25, 1950, the North Korean military made a surprise attack and crossed the 38th parallel north and invaded South Korea. Since being liberated from the Japanese Occupation in 1945, the Korean Peninsula was split into the military government regions of the USSR and the USA. Three years later, South and North Korea founded their separate governments, and the tension between the two sides exploded as North Korea attempted to unify the nation by force.

Unlike the North Korean Army that prepared for this attack for a long time, the South Korean Army was not ready for war. The main forces of the North Korean and South Korean armies clashed in the northern part of Seoul, but South Korea was defeated by the North Korean tanks. The South Korean Army that lost the capital, Seoul on June 28th delayed the advance of North Korea at its defense line on the Han River for one week.

After hearing news of the North Korean invasion, the US government immediately held a UN Security Council meeting and decided to enter the war on the 28th. Task Force Smith was the first US military unit deployed to Korea on July 5th, and it fought its first battle against the North Korean military at Jukmiryeong in Osan. The North Korean Army was still advancing quickly southward, but the South Korean Army and UN Forces slowed their advance while waiting for more reinforcements.

In early August 1950, more than a month after the outbreak of the war, North Korean forces reached the River Nakdong. There was a fierce battle between the North and South Korean Armies, where the North wanted to take the last remaining territory of the Republic of Korea, and the battle, with combined South Korean and UN Forces, managed to keep North Korea at bay for about a month. The final onslaught by North Korea continued until September failed in the footsteps of Daegu.

The UN Command decided to land on the rear lines of the North Korean military to overturn the tides of war with a single swipe.While the fight for the defense of River Nakdong was at its peak, the UN Forces successfully landed two divisions in Incheon on September 15th and recaptured Seoul on the 28th. Thus, the main supply route of North Korea from Pyongyang to Seoul to Busan was severed, and the North Korean military began to rapidly collapse on all fronts.

The combined South Korean and UN Forces that began their counteroffensive from the Nakdonggang River defense line successfully took back all of the South Korean territories in just two weeks. The South Korean Army crossed the 38th parallel for the first time at Yangyang on October 1st and advanced northward to hold North Korea responsible for attacking South Korea and to unify the Korean Peninsula. The combined South Korean and UN Forces soon pushed north on all fronts, capturing major cities including Pyongyang and Wonsan, and continued to march to the border with Manchuria.

As the tides of war turned, North Korea reached out to the USSR and China for help, and China responded by entering the Korean War by deploying about 200,000 soldiers. The advance of the South Korean and UN Forces reached the northernmost point of the Korean Peninsula at the Amnok (Yalu) River and Tumen River, but they faced a crisis with the sudden participation of the Chinese Army.

The war now escalated with the addition of a new enemy. Unprepared for this situation, the South Korean and UN Forces retreated to the 38th parallel by December 14th. In Hamgyeongbuk-do, the US 10th Corps and about 100,000 North Korean refugees who were surrounded by the Chinese Army escaped to South Korea via Hungnam Port.

The Chinese Army captured Seoul in January of 1951 and continued to press south, but their advance was stopped at the 37th parallel north. The South Korean and UN Forces seized this opportunity and went on a counteroffensive and recaptured Seoul in March, and they  pushed up to the 38th parallel. During this time, the stage was set for frontline battles that would continue for the next two years.

As the war started to fall into a stalemate, the UN and communist parties began talks for ceasefires at Kaesong. The talks lasted two years and involved whether to continue battles, withdrawal of foreign forces, and issues related to the exchange of prisoners.

Believing that a permanent demarcation line would be determined depending on the results of the ceasefire talks, the armies on the two sides began fighting to gain more advantageous land. Hills that would gain control over the surrounding area became the main battlegrounds, and the fierce war of attrition where hills changed hands continued day and night. To the west, there were many battles, including the Battle of the Hook, the Battle of Nori Hill, the Battle of Old Baldy, the Battle of White Horse, the Battle of Triangle Hill, the Battle of Capitol Hill, the Battle of Heartbreak Ridge, and the Battle of Hill 351… Many soldiers sacrificed their lives on numerous hills.

The war of ideologies was being held not only on the battlefronts but also at prison camps. Communist army prisoners captured by the UN Forces were split into pro-communist and anti-communist, where they were in fierce opposition to each other. The pro-communist prisoners kidnapped the head of the prison camp and had a huge impact on the ceasefire talks regarding issues with the repatriation of prisoners.

After two long years of suffering, the two sides reached an agreement on the military demarcation line and prisoner exchange, finally signing a ceasefire agreement after 1,127 days of the war. This war that cost the lives of 620,000 South Korean soldiers, 990,000 civilians, and 140,000 UN troops while turning the Korean Peninsula into a wasteland ended as an unresolved war.