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Operation Chromite: The Invasion of Inchon

15 September 1950 

Wolmi-do and Inchon. Drawing, colored pencil on paper, by Herbert C. Hahn, ca. 1951 (88-191-BB).

Wolmi-do and Inchon. Drawing, colored pencil on paper, by Herbert C. Hahn, ca. 1951 (88-191-BB).

“I can almost hear the ticking of the second hand of destiny,” General Douglas MacArthur told his subordinates on 23 August 1950; “We shall land at Inchon, and I shall crush them.”[1]

MacArthur was then the commander in chief of United Nations forces (Korea), who now found themselves in a war over the future of the Korean peninsula—whether it would turn communist and become a vassal state of China or whether it would achieve lasting independence and integration into a world order led by the United States and its allies.

In the two months leading up to MacArthur’s pronouncement of 23 August 1950, the conflict in Korea was giving way to a string of communist victories achieved by the North Korean People’s Army (NKPA). On 26 June, the enemy drew close enough to Seoul that USS Mansfield (DD-728) and USS De Haven (DD-727) had to assist in the emergency evacuation of some 700 U.S. citizens and foreign nationals likely to be interned or executed by the communist conquerors, who besieged and occupied the city two days later.[2]

It was in the weeks after this episode, a low point in U.S. and U.N. fortunes, that MacArthur began to consider an invasion of Inchon (Inch’ŏn) to regain Seoul and thereby sap the communists’ morale. There was also a strategic advantage, MacArthur believed, to holding the capital and the nearby port city of Inchon. Whether he was right continues to be a topic of some controversy among historians.


As planning got underway for the invasion of Inchon, code-named Operation Chromite, most of the fighting was happening elsewhere, in the southeastern corner of the Korean peninsula. U.N. forces referred to this region as the “Pusan perimeter,” because its principal point of entry and most important strategic stronghold was the port city of Pusan. As of August 1950, the perimeter cut a somewhat rectangular shape of about 75 miles north to south and not quite as many east to west. U.N. forces fought to hold the area from within as NKPA troops assaulted it from without.

When U.N. forces gained the tentative upper hand in in August, MacArthur began slowly to redistribute troops and supplies for the opening of a second front: the invasion of Inchon.   

Inchon, on the other side of the Korean peninsula, was the country’s second-largest port (after Pusan) and the main port for Seoul, just 15 miles away. Inchon also sat at a main nexus of Korea’s rail and road networks. It had strategic value, certainly, yet the daily cargo capacity was only 10 percent of Pusan’s.[3]

The prime rationale for taking Inchon and then Seoul had less to do with attaining concrete strategic advantages and more to do with leveling a grievous psychological blow on the communists. Seoul was Korea’s largest and most modern city, if also an ancient center of government and ceremony. Fated for destruction, Seoul would change hands six times before the Korean War ended three years later.

Objectives and Obstacles

Originally named Operation Bluehearts, Operation Chromite incorporated a series of objectives that had to happen in order:

  1. Capture Wolmi-do, a fortified island in the Yellow Sea (connected by isthmus to the mainland), else the Navy convoy carrying Marines and Soldiers would be subject to deadly bombardment;
  2. Land Marines and then follow-up personnel at coastal areas near Inchon and capture the city, thereby opening a way to Seoul and depriving NKPA of supplies that came into Inchon and traveled by road and rail via Seoul;
  3. Seize nearby Kimpo Airfield for future use as a base for U.S. and allied aircraft;
  4. Retake Seoul.

The obstacles to success were formidable. Reefs and shoals littered the approach to Inchon from the Yellow Sea, where a swift current further complicated navigation. At the landing sites, moreover, the effects of the tides were perilous. At low tide, the water’s depth fell below the threshold for LSTs (tank landing ships), which could easily run aground and therefore impede the process of getting essential equipment to shore. At such times, the harbor itself degenerated into a three-mile-wide quagmire, which met dry land not at beaches but at a complex of 12-foot sea walls. Marines would need to use specially built scaling ladders—and this under what might be heavy fire from enemy emplacements atop steep hills near the coast.[4]

The Navy and Marines would have to accomplish these landings in three-hour periods—one at each tide—or face catastrophe. The main landing itself would need to occur at a time in the tide cycle that afforded just two hours of daylight for the assault.

No one but MacArthur thought any of this was a good idea. On 23 August, he met with his subordinate commanders in Tokyo to hear their objections. Admiral Forrest P. Sherman, Chief of Naval Operations (CNO), also shared his serious concerns. MacArthur listened and then commenced a 45-minute rebuttal. Despite the objections of the CNO and the Joint Chiefs of Staff, MacArthur insisted on Inchon. “The very arguments you have made as to the impracticabilities involved,” he argued, “will tend to ensure that no one would be so brash as to make [the] attempt,” and that was all the more reason to do it. The NKPA would be shocked, caught off guard, and subsequently defeated.[5] However tortuous his logic, MacArthur turned out to be right—at least in the short term.

Planning and Preparations

To accomplish this daring amphibious assault and the subsequent seizure of Seoul, MacArthur created “X Corps,” a massive joint force placed under the command of MacArthur’s chief of staff, Major General Edward M. Almond, USA. Activated only 20 days before the operation was to begin, X Corps and its staff officers had to proceed quickly with the planning. Although some of them had been working on preliminary plans since 12 August, planning for the main landing itself did not get underway until two weeks before D-day, when Navy and Marine officers met in Japan to confer.[6]

The final plans emerged for MacArthur’s approval on 4 September. A landing team of the 5th Marines would come ashore at Wolmi-do, the fortified island near Inchon, at 6:30 a.m. and neutralize it in short order; 11 hours was the longest it could take before the next tide was to bring in the first wave of Marines bound for Inchon.

Those landings would take place at two areas, one to the northwest of Inchon and the other to the southeast. To land the first Marines, as well as other personnel in subsequent landings—in total nearly 70,000 men—the operation would require 230 ships from seven navies. Overhead, aircraft of the U.S. Navy, the U.S. Marine Corps, and the British Royal Navy would support the assault.[7]

The naval force for the operation would be Joint Task Force 7, commanded by Vice Admiral Arthur D. Struble. Rear Admiral James H. Doyle was second in command.

At Pusan on 8 September, Marines commenced loading vessels for the operation and, around the same time, the naval gunfire support group started bombarding the fortifications at Wolmi-do in preparation for the first landings near Inchon. Unfortunately, two back-to-back typhoons (10–13 September) complicated subsequent preparatory work, but not seriously.

To confuse the enemy, the British put a landing party at Kunsan (Gunsan) and bombed Chinnampo (Namp’o).[8] Meanwhile, the massive U.N. convoy steamed toward Inchon.


On 15 September, almost everything went according to plan. By midnight, U.S. Marines had almost entirely subdued Inchon. Only at one point during the day did things go seriously wrong. This had been in the early evening, when the tides had threatened to beach several of the vessels. The result: Marines had to wade through the mud to the seawall. Smoke and light rain further hampered visibility as the sun set. Nevertheless, the Marines and all of their equipment made it over the wall close to the appointed time.

Kimpo Airfield became a battlefield on the following day, 16 September, while the Army’s 7th Infantry Division was coming ashore at Inchon. Meanwhile, the 1st and 5th Marines joined on land and pushed together toward Seoul. By 19 September, they had taken control of Han River’s south bank, whereupon they faced their first truly determined counterattacks by NKPA forces.[9] Still, U.S. and U.N. forces were fighting in the city proper by 21 September and had taken it by the 28th.[10]


Although there were few casualties in the invasion of Inchon itself, the whole campaign, including the attack on Seoul, cost X Corps something close to 3,500 men, a full 2,450 of whom were Marines.[11] (The NKPA suffered around 14,000 casualties. A further 7,000 North Koreans became prisoners of war.) It had been an extremely costly invasion.

The question of the value of the operation to the U.N. war effort is still open as far as historians are concerned.

There is agreement that the campaign itself was a great success. As Allan R. Millett points out, the conquest of Seoul “ended with the restoration of South Korea now assured,” even if it did not obviate the North Korean threat. Historian Spencer Tucker argues that the invasion of Inchon helped U.N. forces at the Pusan perimeter, where General Walton Walker’s Eighth Army broke out and eventually linked up with Marines and Soldiers who had come ashore at Inchon.[12]

By the end of September, MacArthur could point to some spectacular victories. These virtually dumfounded his critics among the Army, the Joint Chiefs of Staff, and even British military and civilian officials.

The victory was also good for X Corps’ Major General Almond, as well as the 1st Marine Aircraft Wing and Admiral Doyle’s Task Force 90 (Pacific Amphibious Force). The accomplishments of Task Force 77, too, were particularly impressive.[13] On 17 September, two days after the first landings near Inchon, TF 77 completed 304 sorties and bombed as many as 200 enemy vehicles. On the day Seoul fell, 28 September, the task force counted 3,330 sorties since the invasion began.[14]

Unfortunately, the triumphal atmosphere among U.S. and U.N. officers and officials soon turned into something else—what Millet identifies as “victory disease,” a “false sense of optimism about the course of the war.”[15]

The success of the Inchon-Seoul campaign also succeeded in horrifying the communists—so much so that they escalated the war in order to win it. This response spelled disaster for the United States and its allies.

Chinese historian Zhihua Shen characterizes the weeks after Inchon as a crisis point for the communist camp. So shaken was Mau Zedong, chairman of the Communist Party of China, by the loss of Seoul and the retreat of the NKPA that he now, more than ever, felt compelled to intervene. The only thing stopping him was a lack of air support from the Soviet Union.

Joseph Stalin, general secretary of the Communist Party of the Soviet Union, remained undecided. He still approached the Korean conflict with a good deal of caution, wanting to avoid outright war with the United States while also wanting to check China’s growing influence within the communist bloc. Yet Stalin also would have equated a U.N. victory there and the reestablishment of the pro-American Republic of Korea as a threat to the security of the bloc.[16]

From archival material in Beijing and Moscow, historians now know that Stalin followed events in and around Inchon and Seoul in the period 14–18 September 1950. We also know that he received, on 30 September, the report he had been dreading: The NKPA had retreated north, and Seoul had fallen to the enemy. On the same day, Stalin and Mao received appeals from Kim Il-sung, the North Korean leader; he was practically begging for intervention—“direct military assistance,” and perhaps, even, “an international volunteer army of China and other people’s democratic [communist] countries.”[17]

The advent of such an army would have amounted to the beginnings of another world war, just five years after the end of the last one, with U.N. forces, Korean forces, Soviet forces, Chinese forces, and forces of the rest of the communist bloc embroiled in armed conflict that would easily—perhaps automatically—spread to other regions and other continents.

Stopping short of such a move, Stalin nonetheless agreed to give Mao the air support he needed.[18] He also gave his support to a full-on Chinese invasion of Korea, at which point U.N.—and U.S.—fortunes changed for the worse and profoundly.

From then on, as historian Charles S. Young puts it, Korea became “a miserable war” during which U.S. troops would make “the longest retreat in U.S. history—at the hands of Chinese peasants,” who had taken up arms to fight the capitalist invaders.[19] Yet Young is not so quick to finger Inchon as the culprit. For him, the subsequent decision, also MacArthur’s, to cross the 38th parallel and make for the Chinese border was the escalation that led to a trench-bound stalemate and nearly three years of bloodshed.

In the final analysis, what is clear from historians’ diverse assessments is that Inchon was the first step on the path to a much larger, much more destructive, and much less winnable war than President Harry S. Truman or any of his counterparts in the free world had anticipated.

—Adam Bisno, PhD, NHHC Communication and Outreach Division, September 2019


[1] Quoted in Spencer Tucker, “Inchon Landings, 1950,” in The Korean War: An Encyclopedia, ed. Stanley Sandler (New York: Garland, 1995), 142.

[2] Commander in Chief, U.S. Pacific Fleet, Korean War: U.S. Pacific Fleet Operations–Interim Evaluation Report No. 1, Covering Period 25 June to 15 November 1950 (hereafter: Interim Evaluation Report), 15.

[3] Tucker, “Inchon Landings,” 142.

[4] Ibid.

[5] Ibid.

[6] Interim Evaluation Report, 85.

[7] Tucker, “Inchon Landings,” 143.

[8] Interim Evaluation Report, 18; Tucker, “Inchon Landings,” 143.

[9] Ibid.

[10] Allan R. Millett, The War for Korea: They Came from the North (Lawrence, KS: University Press of Kansas, 2010), 254.

[11] Ibid., 256. Cf. Interim Evaluation Report, 19.

[12] Tucker, “Inchon Landings,” 144.

[13] Millett, War for Korea, 240.

[14] Interim Evaluation Report, 19

[15] Millett, War for Korea, 240.

[16] Robert O. Paxton, Europe in the Twentieth Century, 4th edition (Boston: Houghton Mifflin, 2005), 484.

[17] Zhihua Shen, “China and the Dispatch of the Soviet Air Force: The Formation of the Chinese-Soviet-Korean Alliance in the Early Stage of the Korean War,” in The Korean War at Sixty: New Approaches to the Study of the Korean War, ed. Steven Casey (London: Routledge, 2012), 58–60.

[18] Ibid., 60. See also Robert Barnes, “Branding an Aggressor: The Commonwealth, the United Nations, and the Chinese Intervention in the Korean War, November 1950–January 1951,” in Korean War at Sixty (op. cit.), 69–91.

[19] Charles S. Young, “POWs: The Hidden Reason for Forgetting Korea,” in Korean War at Sixty (op. cit.), 156.

NKPA (North Korean People’s Army) Gains, 30 June–1 August 1950 (NH 97052).

NKPA (North Korean People’s Army) Gains, 30 June–1 August 1950 (NH 97052).

Movement to the Objective Area, Inchon Invasion, September 1950, showing the route taken by the invasion forces to reach Inchon. (NH 97053).

Movement to the Objective Area, Inchon Invasion, September 1950, showing the route taken by the invasion forces to reach Inchon. (NH 97053).

Photo #: SC 348448 Inchon Invasion, September 1950

Inchon Invasion, September 1950. General of the Army Douglas MacArthur (seated, center,), Commander in Chief U.N. forces in Korea, on board Mount McKinley (AGC-7) during the Inchon landings, 15 September 1950. Others present are (from left to right) Rear Admiral James H. Doyle, USN, Commander Task Force 90; Brigadier General Edwin K. Wright, USA; and Major Gneneral Edward M. Almond, USA, Commander Tenth Corps (SC 348448).

Gate to the City Seoul, Korea

Gate to the City, Seoul, Korea. Drawing, pencil on paper, by Hugh Cabot, circa 1951 (88-187-DS).

Inchon Invasion, September 1950. First Lt. Baldomero Lopez, USMC, leads 3rd Platoon, Company A, 1st Battalion, 5th Marines over the seawall on the northern side of Red Beach, as the second assault wave lands, 15 September 1950. Wooden scaling lad...

Inchon Invasion, September 1950. First Lt. Baldomero Lopez, USMC, leads 3rd Platoon, Company A, 1st Battalion, 5th Marines over the seawall on the northern side of Red Beach, as the second assault wave lands, 15 September 1950. Wooden scaling ladders are in use to facilitate disembarkation from LCVP (landing craft for vehicles and personnel) that brought these men to the shore. Lt. Lopez was killed in action within a few minutes, while assaulting a North Korean bunker (NH 96876).

Inchon Invasion, September 1950. An LST (tank landing ship) slips into Inchon harbor in the early hours of 15 September 1950, just prior to the landings there (80-G-423206).

Inchon Invasion, September 1950. An LST (tank landing ship) slips into Inchon harbor in the early hours of 15 September 1950, just prior to the landings there (80-G-423206).

Published: Thu Sep 10 10:25:21 EDT 2020