The Battle of Inchon (Korean: 인천 상륙 작전, Hanja: 仁川上陸作戰, Incheon Sangnyuk Jakjeon; code name: Operation Chromite) was an amphibious invasion and battle of the Korean War that was conducted with a nearly 40 to 1 troop ratio in favor of UN forces and resulted in a decisive victory and strategic reversal in favor of the United Nations (UN).
The battle began on September 15, 1950, and ended around September 17. Through a surprise amphibious assault far from the Pusan Perimeter that UN and South Korean forces were desperately defending, the largely undefended city of Incheon was secured after being bombed by UN forces. The battle ended a string of victories by the invading North Korean People's Army (NKPA). The subsequent UN recapture of nearby Seoul severed the NKPA's supply lines, placing North Korean forces in South Korea in a dangerously untenable situation.
The majority of United Nations ground forces involved were U.S. Marines, commanded by General of the Army Douglas MacArthur. MacArthur was the driving force behind the operation, overcoming the strong misgivings of more cautious generals to a risky assault over extremely unfavorable terrain.
The idea to land UN forces at Incheon was suggested by MacArthur after he visited the Korean battlefield on June 29, 1950, four days after the war began. MacArthur thought that the North Korean army would push the South Korean army back far past Seoul. He decided that the battered, demoralized, and under-equipped South Koreans, many of whom did not support the SK government put in power by the US (citation needed), could not hold off the NKPA, who also defeated the American reinforcements. MacArthur felt that he could turn the tide if he made a decisive troop movement behind enemy lines. He hoped that a landing near Incheon would allow him to cut off the NKPA and destroy that army as a useful fighting force, thus winning the war.
In order to accomplish such a large amphibious operation, MacArthur requested the use of United States Marine Corps expeditionary forces, having become familiar with their ability to integrate amphibious operations in the Pacific during World War II. However, the Marines at that point were still recovering from a series of severe program cutbacks instituted by the Truman administration and Secretary of Defense Louis A. Johnson. Indeed, Johnson had tried to eliminate the Marines entirely and slashed Marine expeditionary forces from a World War II peak of 300,000 men to just over 27,000. Much of the Marines' landing craft and amphibious carriers had been sold off, scrapped, or transferred to the exclusive use of the U.S. Army.
After hastily re-equipping Marine forces with aging World War II landing craft, withdrawing Marine units from the Pusan perimeter, and stripping recruitment depots bare of men, Marine commanders were just able to mount a force capable of undertaking offensive operations against the small NK forces.
MacArthur decided to use the Joint Strategic and Operations Group (JSPOG) of his Far East Command (FECOM). The initial plan was met with skepticism by the other generals because Incheon's natural and artificial defenses were formidable. The approaches to Incheon were two restricted passages, Flying Fish and Eastern channels, which could be easily blocked by mines.
The current of the channels was also dangerously quick—three to eight knots. Finally, the anchorage was small and the harbor was surrounded by tall seawalls. Commander Arlie G. Capps noted "We drew up a list of every natural and geographic handicap—and Incheon had 'em all."
These problems, along with the advancing North Korean army, forced MacArthur to abandon his first plan, Operation Bluehearts, which called for an Incheon landing in July 1950.
Despite these obstacles, in September MacArthur issued a revised plan of assault on Incheon: Plan 100-B, codenamed Operation Chromite. A briefing led by Admiral James Doyle concluded "the best that I can say is that Incheon is not impossible." Officers at the briefing spent much of their time asking about alternative landing sites such as Kunsan. MacArthur spent 45 minutes after the briefing explaining his reasons for choosing Incheon.
He said that because it was so heavily defended, the enemy would not expect an attack there, that victory at Incheon would avoid a brutal winter campaign, and that, by invading a northern strong point, the UN forces could cut off North Korean lines of communication. Incheon was also chosen because of its proximity to Seoul. Admiral Forrest P. Sherman and General J. Lawton Collins returned to Washington, D.C., and had the invasion approved.
The landing at Incheon was not the first large-scale amphibious operation since World War II. That distinction belonged to the July 18, 1950 landing at Pohang. However, that operation was not made in enemy-held territory and was unopposed.
Before the main land battle, U.N. forces landed spies in Inchon and bombarded the cities defenses via air and sea.
Seven days before the main attack on Incheon, a joint Central Intelligence Agency–military intelligence reconnaissance, codenamed Trudy Jackson, placed a team of guerrillas in Incheon. The group, led by Navy Lieutenant Eugene Clark, landed at Yonghung-do, an island in the mouth of the harbor. From there, they relayed intelligence back to U.S. forces.
With the help of locals, the guerrillas gathered information about tides, mudflats, seawalls and enemy fortifications. The mission's most important contribution was the restarting of a lighthouse on Palmi-do.
When the North Koreans discovered that the allied agents had entered the peninsula, they sent an attack craft with 16 infantrymen. Eugene Clark mounted a machine gun on a sampan and sank the attack boat. In response, the North Koreans killed up to 50 civilians for helping Clark.
A series of drills and tests and raids were conducted elsewhere on the coast of Korea, where conditions were similar to Incheon, before the actual invasion. These drills were used to perfect the timing and performance of the landing craft.
On September 10, 1950, five days before the Incheon landing, 43 American warplanes flew over Wolmi, dropping 93 napalm canisters to “burn out” its eastern slope in an attempt to clear the way for American troops.
As the landing groups neared, cruisers and destroyers from the United States and Canada shelled the fortified Wolmi-do Island and checked for mines in Flying Fish Channel. The first Canadian forces entered the Korean War when HMCS Cayuga, HMCS Athabaskan and HMCS Sioux bombarded the coast. The Fast Carrier Force flew fighter cover, interdiction, and ground attack missions. Hundreds of Korean civilians were killed in these attacks on the lightly defended port.
Destroyer Squadron Nine, headed by the USS Mansfield, sailed up Eastern Channel and into Inchon Harbor, where it fired upon enemy gun emplacements at Wolmi-do. The attacks tipped off the North Koreans that a landing might be imminent. The North Korean officer at Wolmi-do assured his superiors that he would throw the enemy back into the sea.
Throughout the naval bombardment, one U.S. sailor was killed and six U.S. others were wounded, the one dead, David H. Swenson from USS Lyman K. Swenson, was later reported by the world media as being the nephew of Captain Lyman Knute Swenson, USS Swenson's namesake, but this was later found to be false. Significant damage was inflicted on three of the attacking warships; USS Swenson which suffered the one dead sailor and another man wounded.
USS Collett, received the most damage, she took nine 75-millimeter hits, one of which disabled her computer and wounded five men. USS Gurke sustained three hits resulting in light damage and no casualties. Over a thousand 5-inch shells were fired by the Canadian-American destroyer force, after inflicting severe damage on Wolmi-do's fortifications for an hour. Canadian casualties are unknown if any.
The destroyers withdrew and allied cruisers proceeded to bombard the North Korean batteries from the south of the island.
The flotilla of ships that landed during the battle was commanded by VADM Arthur Dewey Struble, an expert in amphibious warfare. Struble had participated in amphibious operations in World War II, including the Battle of Leyte and the Battle of Normandy.
At 06:30 on September 15, 1950, the lead elements of X Corps hit "Green Beach" on the northern side of Wolmi Island. The landing force consisted of the 3rd Battalion 5th Marines and nine M26 Pershing tanks from the 1st Tank Battalion. One tank was equipped with a flamethrower (flame tank) and two others had bulldozer blades. The battle group landed in LSTs designed and built during World War II. The entire island was captured by noon at the cost of just 14 casualties.
North Korean force was outnumbered by more than 6 to 1 by foreign troops. North Korean casualties included over 200 killed and 136 captured, primarily from the 918th Artillery Regiment and the 226th Independent Marine Regiment. The forces on Green Beach had to wait until 19:50 for the tide to rise, allowing another group to land. During this time, extensive shelling and bombing, along with anti-tank mines placed on the only bridge, kept the small North Korean force from launching a significant counterattack. The second wave came ashore at "Red Beach" and "Blue Beach."
The North Korean army had not been expecting an invasion at Incheon. After the storming of Green Beach, the NKPA assumed (probably because of deliberate American disinformation) that the main invasion would happen at Gunsan. As a result, only a small force was diverted to Incheon. Even those forces were too late, and they arrived after the UN forces had taken Blue Beach and Red Beach. The troops already stationed at Incheon had been weakened by Clark's guerrillas, and napalm bombing runs had destroyed key ammunition dumps. In total, 261 ships took part.
The Red Beach forces, made up of the Regimental Combat Team 5, which included the 3rd Battalion of the Republic of Korea Marine Corps (ROKMC), used ladders to scale the sea walls. After neutralizing North Korean defenses, they opened the causeway to Wolmi-Do, allowing the tanks from Green Beach to enter the battle. Red Beach forces suffered eight dead and 28 wounded.
Under the command of then-Colonel Lewis Burwell "Chesty" Puller, the 1st Marine Regiment landing at Blue Beach was significantly south of the other two beaches and reached shore last. As they approached the coast, the combined fire from several NKPA gun emplacements sank one LST. Destroyer fire and bombing runs silenced the North Korean defenses. When they finally arrived, the North Korean forces at Incheon had already surrendered, so the Blue Beach forces suffered few casualties and met little opposition. The 1st Marine Regiment spent much of its time strengthening the beachhead and preparing for the inland invasion.
Immediately after North Korean resistance was extinguished in Incheon, the supply and reinforcement process began. Seabees and Underwater Demolition Teams (UDTs) that had arrived with the U.S. Marines constructed a pontoon dock on Green Beach and cleared debris from the water. The dock was then used to unload the remainder of the LSTs.
Documents written by Kim Il Sung and recovered by UN troops soon after the landing said, "The original plan was to end the war in a month, we could not stamp out four American divisions...We were taken by surprise when United Nations troops and the American Air Force and Navy moved in."
On September 16, the North Koreans, realizing their blunder, sent six columns of T-34 tanks to the beachhead. In response, two flights from F4U Corsair squadron VMF-214 bombed the attackers. The armored columns suffered extensive damage and the US forces lost one airplane. A quick counter-attack by M26 Pershing tanks destroyed the remainder of the North Korean armored division and cleared the way for the capture of Incheon.
On September 19, the U.S. Army Corps of Engineers repaired the local railroad up to eight miles (13 km) inland. The Kimpo airstrip was captured, and transport planes began flying in gasoline and ordnance for the aircraft stationed at Incheon. The Marines continued unloading supplies and reinforcements. By September 22, they had unloaded 6,629 vehicles and 53,882 troops, along with 25,512 tons (23,000 tonnes) of supplies.
In contrast to the quick victory at Incheon, the advance on Seoul was slow and bloody. The NKPA launched another T-34 attack, which was trapped and destroyed, and a Yak bombing run in Incheon harbor, which did little damage. The NKPA attempted to stall the UN offensive to allow time to reinforce Seoul and withdraw troops from the south. Though warned that the process of taking Seoul would allow remaining NKPA forces in the south to escape, MacArthur felt that he was bound to honor promises given to the South Korean government to retake the capital as soon as possible.
On the second day, vessels carrying the U.S. Army's 7th Infantry Division arrived in Incheon Harbor. General Almond was eager to get the division into position to block a possible enemy movement from the south of Seoul. On the morning of September 18, the division's 2nd Battalion of the 32nd Infantry Regiment landed at Incheon and the remainder of the regiment went ashore later in the day. The next morning, the 2nd Battalion moved up to relieve an U.S. Marine battalion occupying positions on the right flank south of Seoul. Meanwhile, the 7th Division's 31st Regiment came ashore at Incheon. Responsibility for the zone south of Seoul highway passed to 7th Division at 18:00 on September 19. The 7th Infantry Division then engaged in heavy fighting with North Korean soldiers on the outskirts of Seoul.
Before the battle, North Korea had just one understrength division in the city, with the majority of its forces south of the capital. MacArthur personally oversaw the 1st Marine Regiment as it fought through North Korean positions on the road to Seoul. Control of Operation Chromite was then given to Major General Edward Almond, the X Corps commander. It was Almond's goal to take Seoul on September 25, exactly three months after the beginning of the war. On September 22, the Marines entered Seoul to find it heavily fortified. Casualties mounted as the forces engaged in desperate house-to-house fighting. Anxious to pronounce the conquest of Seoul, Almond declared the city liberated on September 25 despite the fact that Marines were still engaged in house-to-house combat (gunfire and artillery could still be heard in the northern suburbs).
The last North Korean troops in South Korea still fighting were defeated when Walker's 8th Army broke out of the Pusan perimeter, joining the Army's X Corps in a coordinated attack on NKPA forces. Of the 70,000 NKPA troops around Pusan, more than half were killed or captured. However, because UN forces had concentrated on taking Seoul rather than cutting off the NKPA's withdrawal north, the remaining 30,000 North Korean soldiers escaped to the north across the Yalu River, where they were soon reconstituted as a cadre for the formation of new NKPA divisions hastily re-equipped by the Soviet Union. The allied assault continued north to the Yalu River until the intervention of the People's Republic of China in the war.
The battle is considered one of the most decisive military operations in modern warfare.
However Stolfi (2004) argues that the landing itself was a strategical masterpiece but it was followed by an advance to Seoul in ground battle so slow and measured that it constituted an operational disaster, largely negating the successful landing. He contrasts the US style of war fighting with that of Germany by examining the US military's 1950 Incheon-Seoul operation and the German offensive in the Baltic in 1941. American forces achieved a strategic masterpiece in the Incheon landing in September 1950 and then largely negated it by a slow, tentative, 11-day advance on Seoul, only twenty miles away. By contrast in the Baltic region in 1941 the German forces achieved strategic surprise in the first day of their offensive and then, exhibiting a breakthrough mentality, pushed forward rapidly, seizing key positions and advancing almost two hundred miles in four days. The American advance was characterized by cautious, restrictive orders, concerns about phase lines, limited reconnaissance, and command posts well in the rear, while the Germans positioned their leaders as far forward as possible, relied on oral or short written orders, reorganized combat groups to meet immediate circumstances, and engaged in vigorous reconnaissance. The Germans, Stolfi concludes, were better practitioners of mobile warfare.
The Battle of Incheon was the subject of the 1982 film Inchon, which did poorly at the box office amid controversy over its being partially financed by Unification Church leader Sun Myung Moon. Previously, the Battle of Incheon was featured in Joseph H. Lewis's 1952 film for Milton Sperling and Warner Brothers Retreat, Hell!.
The concert band work "Incheon" by Robert W. Smith is about the battle. It begins with a flute solo, and slowly brings in percussion sound effects, such as machine gun and artillery fire and helicopter noise. It also has references to Variations on a Korean Folk Song (measures 61, 62, 65, and 66).
The W. E. B. Griffin novel Under Fire is a fictionalized account of the political and personal maneuvering that occurred during MacArthur's development of the Incheon invasion plan.