At 4:00 am on June 25, 1950, the North Korean army launched an all-out attack at the 38th parallel. Little regard was paid to the event, because similar military action had occurred in the area previously. In the meantime, the North Korean army advanced to Seoul, which collapsed on June 29, 1950, only four days after the war began. The whole area, aside from a portion of Nakdonggang River, was occupied by North Korea within a month. In response, the UN sent support forces to the Busan harbor. At that time, Douglas MacArthur was commander-in-chief of the UN forces. He believed a full-scale war would result in too much damage, and therefore suggested an alternative: Operation Chromite, which had a 5000:1 probability of success. Despite significant opposition, Operation Chromite was approved by the US forces.
Why was Incheon selected?
1. Incheon is what North Korea napped as much as probability of success is 5000:1.
2. Incheon was located near Seoul, so its harbor was closest to Seoul.
3. If South Korea and the UN recaptured Seoul, they could strike a psychological blow against North Korea, and cut off North Korea’s supply routes.
Why was Incheon unsuitable for selection?
1. The waterway to Incheon was small, so large-scale warships could not enter.
2. If North Korea laid mines, South Korea would sustain significant damage.
3. Incheon had a large tidal range, around 10m.
4. Before landing in Incheon harbor, South Korea would have to occupy Wolmi-do.
Before approving or launching Operation Chromite, MacArthur had to obtain prior information, not with aerial photographs or communications equipment but through accurate reports of what people saw and heard. MacArthur assigned intelligence operations to the Republic of Korea (ROK) navy. In August 1950, 17 Underwater Demolition Unit (UDU), including Major Ham Myeong-su, dropped anchor at Yeongheungdo. They obtained detailed information on sea defenses, locations and numbers of coast batteries, and minefields, and reported back to headquarters.
Starting on September 5, South Korea began bombing north into Pyeongyang and south into Gunsan (a candidate considered for Operation Chromite) to distract the enemy. To reinforce the ruse, MacArthur landed troops on Jangsa coast, known as the Jangsa landing operation. Because of this, the enemy turned their eyes and concentrated upon the east.
Meanwhile, to ensure the success of Operation Chromite, the allied forces had to occupy Wolmi-do. To this end, they needed to take control of Palmido lighthouse, which provided a sight line to all of Incheon Bay. The Korea Liaison Office (KLO), a secret intelligence organization within the US forces and ROK-US special forces, fought a fierce battle, finally recapturing the lighthouse at 10:00 pm on September 14. At 12:00 am on September 15, they lit the lighthouse lamp. MacArthur identified the light and commanded the combined fleet of 261 vessels to advance. Operation Chromite had officially begun. Forces had to occupy Wolmi-do before Incheon harbor; therefore, ROK-US forces carried out a two-stage operation, occupying Wolmi-do in the morning and Incheon in the evening. Wolmi-do was dominated in just two hours. Subsequently, the First Regiment of the national marines, the Seventeenth Regiment of the national army, seven US Infantry divisions, and one division of Marines advanced to attack Incheon Bay. They started to rally North Korea’s main force and dominated Incheon successfully. Seoul was recaptured on October 19, they advanced to the Amnokgang River on November 1, and the invasion of the Communist Chinese army took place on November 4. Ultimately, a cease-fire agreement was reached on July 27, 1953.
Two factors contributed to the success of Operation Chromite. First is the Jangsa landing operation, which disturbed enemy to draw attention away from Operation Chromite. A total of 772 student soldiers took part in the Jangsa landing operations, teenagers who had trained for just 15 days. Buoyed by patriotism, they traveled onboard the ferry Munsan, arriving at the Jangsa coast at dawn. Unfortunately, the ferry was grounded by a sudden typhoon, and many of the soldiers were lost at sea. Those who escaped fought with North Korean forces. Later, a rescue ship was sent, but it hauled off quickly because of the risks posed by the typhoon and enemy forces. Ultimately, of the 772 soldiers, 137 were killed, 92 injured, and many went missing. However, because of its top secret nature, this operation was unknown to the world until the ferry was discovered.
The second factor in Operation Chromite’s success was the “X-RAY” plan. Beginning in September 1950, the 17-person UDU including Major Ham Myeong-su collected a month’s worth of intel for Operation Chromite. They acquired information about location of artillery shells, the scale of North Korea’s military forces, and the location of mines. They also snuck into Wolmi-do and kidnapped North Korean soldiers to collect detailed information on North Korea forces. This information was sent to MacArthur, and Operation Chromite was approved based on it. MacArthur ordered the UDU to withdraw on September 14, the day before the operation would commence. One North Korean regiment launched a surprise attack. UDU tried to counter, but were overcome by the greater numbers. Lieutenant Lim Byeon-grae and Sergeant Hong Si-uk arrested instead extricating fellow soldiers. They committed suicide to prevent themselves from betraying information on Operation Chromite.
Operation Chromite presents us with three significant implications. First, it used both physical and psychological attacks to undermine the enemy’s will to resist a raid. This implies an opportunity to change the leadership of war. Second, it minimized losses of time, life, and materials in the South Korean military and US forces. If Operation Chromite had not been approved, the North Korean military would have fought a minimum five delay position to prevent ROK-US Forces’ attack. Losses of over a hundred thousand in the South Korean military and UN forces were expected, along with large-scale massacre of civilians. Third, the commander’s strategic insight and the specialized operational skill of the US Navy and Marine Corps are deserving of appreciation.
When you think of Operation Chromite, what comes to mind? Many people answer “MacArthur” or “UN forces.” Of course, MacArthur’s institution was great and UN forces were strong. However, they were able to record the triumph in history and to make the impossible possible only because of the sacrifice of unknown students, local residents, and national forces. The least we can do is remember them and honor their sacrifice.