The United Nations Effort to End the Korean War  

Operation Chromite

Most historical accounts of military battles are told in a story format with occasional emphasis by the writer on key elements of interest or proof of thesis. This is not the approach that will be taken here in describing the key battle of Operation Chromite during the Korean War (also referred to Korean Conflict). Instead, the military engagement will be broken down and described in terms of operational planning; it’s presented much in the way an Operations Officer and Intelligence Officer views the relative information. In this operational descriptive way the battling contestants’ situations and key factors can more objectively portrayed, not unlike describing a chess game. 

Invasion route for InchonCredit: US Marine Operations in Korea, Vol II, uploaded 2005

Inchon Operations During the Korean War

The Contenders

North Korea

The Democratic People's Republic of Korea (DPRK) was formed in September 1947 by the North Korean government and influenced by the USSR. The DPRK claimed jurisdiction over all of Korea. Their objective was to bring all of Korea under one rule - communist rule. The USSR and Communist China worked behind North Korea to bring about a new unified communist Korea.

United States Objective

The United States objective in Korea was to stop all forms of communist aggression.[1] The US policy during this period was the "general containment of communism by reducing or limiting its commitment and by planning to combat communist expansion only at selected points".[1] The 15th of September 1950, marked the major United Nations offensive to end the North Korean War effort. At least this was General MacArthur's expectation for the U.S. plan named Operation CHROMITE. The offensive action was to contain the North Koreans by an amphibious assault from their rear and cutting off their supply lines.

North Korea Objective

The North Korean (NK for brevity) government's overriding objective was the unification of Korea and the establishment of a communist government throughout the peninsula. NK had received its training, resources and war doctrine from the USSR.[1] USSR maintained close control over the organization and training of the NK Army. Only men of established loyalty to the USSR received command of its units.[1] NK's scheme of maneuver was to move south quickly, swiftly, and with mass across the length of the peninsula. The assault on the south over the 38th parallel commenced with synchronized ground troops, armor, air resources and with an amphibious landing.[1] A large number of the North Korean army soldiers were veterans of past conflicts. They were experienced and fighting on their own ground. The majority of these forces were committed against the Eighth U.S. Army to the South around Pusan.

Intelligence Report

North Korean Forces

Intelligence estimates of the NK forces in 1950 were approximately 135,000 ground troops, 150 tanks (T-34's), 300 light and medium artillery pieces, 750 medium and heavy mortars, and 356 45mm antitank guns. Their Air Force strength estimates were approximately 180 YAK aircraft, 70 IL-10 attack planes and 10 reconnaissance planes. NK army forces were organized into eight infantry divisions, one armor brigade, two half strength divisions, one separate infantry brigade, and a motorcycle reconnaissance regiment.[2]  Strength estimates in Seoul were approximately 500, Inch'on 1,800 - 2500 and at Kimpo Airfield 500 for a total of 7300 - 9000.[2] The composition and disposition of forces was estimated to be a small rear area garrison, lines of communication, units, and newly formed and poorly trained groups scattered throughout Korea back of the combat zone around the Pusan Perimeter. If reinforcements were attempted, it was believed that the "3rd, 13th, and 10th Divisions deployed on either side of the main Seoul-Taegon-Taegon highway, could most rapidly reach" the area of operation.[2]  U.S. estimates in August had NK concentrating nearly all of its combat power against the Eighth Army in the Pusan Perimeter.[1]

United States and South Korean Forces

At the commencement of Operation Chromite US/UN forces were estimated at approximately 150,000 men, including 11,000 South Korean fillers. The 10th U.S. Corps consisted of the 1st Marine Division, the 7th Infantry Division, 92nd and 96th Field Artillery Battalions, 56th Amphibious Tank and Tractor Battalion, 19th Engineer Combat Group, 2nd Engineer Special Brigade, 1st Marine Division and the 7th Marine Division. The 8th U.S. Army consisted of the 24th Infantry Division, 25th Infantry Division, 1st Cavalry Division and the 2nd Infantry Division.[1]

 General of the Army Douglas MacArthur, Commander in Chief, Far East, (center)Credit: Official U.S. Navy Photograph, 1950


MacArthur and his Plan 

MacArthur was looking ahead when he first visited Korea in June. It was then that he originally formulated the idea for this operation. MacArthur planned this adventure without concern that he did not have the necessary resources already at hand, but with the expectation that they would be there. He began planning and coordinating actions well before he had discussed them with the Chiefs of Staffs.[1] He was sure that North Korea would not expect a major offensive against its rear area. So as the old saying goes, he "hit them where they least expected it". MacArthur decided to conduct an operation that he believed would result in a pay-off that outweighed the inherently great difficulties involved.

MacArthur selected the Seoul-Inch'on area as the primary vital spot in the North Korean's lines of communication and resupply. He believed by seizing these two areas he could achieve a "quick and decisive victory over the enemy".[1] Inch'on was the port for Seoul, the closest landing area to the city, and the hub of communications.[1] The fact that the location was a very difficult landing site added to the idea that this would result in total surprise to the North Koreans. MacArthur believed that the enemy had neglected the rear area and "was dangling on a thin logistical rope that could be quickly cut in the Seoul area".[2] He believed that the North Korean reserve was limited and the forces to the rear had little probability of recovering from a rear assault. MacArthur was convinced that an attack at these locations would sever the communications and supply lines, and have the added psychological advantage of degrading and demoralizing the enemy.


F4U-5N returning to USS BoxerCredit: USN - Official U.S. Navy Photograph, 1951

U.S. Navy’s Argument to the Plan

Some part or all of the operation met with opposition from the various service organizations and the executive branch staff in the United States. The Navy was the loudest voice in opposition to the plan in general. The Joint Chiefs of Staff only gave implied approval to MacArthur's plan but never committed to it until nearly two weeks prior to its execution;[1] many senior officers had reservations about the site selected for the invasion. The most vocal opposition to the site came from the Navy.[1] Inch'on was considered one of the worst harbor areas in Korea for navigation, sea approaches and landing beaches. Tide conditions and landing craft requirements limited the time available for use of this location as a landing site. The large number of small islands covering the sea approach in to the port made navigating a fleet into the objective difficult at best.[1] The plan was referred to by MacArthur as an "anvil and a hammer" operation.20 The overall maneuver operation was a doctrinal turning movement.

There were two primary points of vulnerability facing MacArthur: First, the actual landing site, as stated before, was believed by the Navy and by many of his own staff to be too difficult and a risk to attempt. Secondly, the selection of that difficult site was a conscious gamble on North Korea's estimated lack of ability to react to the attack. If MacArthur's gamble had resulted in disaster, the political will of the United States to remain in Korea would have been jeopardized.

Actual Footage from Inchon 1950


The Battle Begins

Battle of Inchon Landing

The first action began in the early morning. The operation commenced with an amphibious landing at Inch'on to the rear of the North Korean forces. The Navy and Air Force provided gunfire and strategic bombing against the North Korean forces facing off with the Eighth Army and simultaneous fires in support of the landing forces. Air attacks continued for eleven days prior to the waterborne and ground attacks. Five days before the main assault, Marine air elements attacked Wolmi-do. Two days prior to the main assault, U.S. Naval forces entered the area in a position to control the inner harbor area of Inch'on. That afternoon of the 13th, the Navy gunfire and air assets began bombarding Wolmi-do.

On the 15th of September the 10th Corp forces arrived off Inch'on.21 The Advanced Attack Group began its movement toward Inch'on at 0200 hours. This action tied down all enemy forces committed against Eighth Army and prevented withdrawal from the south of major reinforcements for the North Korean units opposing the 10th Corps in its landing area.[2] The marines landed and controlled the island within 45 minutes[2] and spent a day preparing for the main landing force. The next day, the main force took the main harbor and secured the city, cutting the enemy off from the main lines of communications and supply.[2]

As a result the US/UN operation, North Korean forces were forced to stop forward movement of their forces and then to defend to their rear.

Eighth Army attacked north from its Pusan Perimeter beachhead to drive northwest along the Taegu-Taejon-Suwon axis to link up with the amphibious force.[2] Kimpo Airfield was the next stop for the main landing force and taken with little resistance. After Kimpo, the marines moved on to the Hawn River. Once the 7th Infantry Division came ashore, the 10th Corp moved into position to take Seoul.[2] On September 16th, the battle at Seoul began and by the 24th, the North Korean forces were pushed out of South Korean territory. On the 26th, the Eighth Army and 10th Corp forces linked up.[2]

First Lieutenant Baldomero Lopez Scaling SeawallCredit: Image from the collections of the Naval Historical Center, 1950

The Outcome

Key points to the failure of the North Koreans were the lack of protection afforded to their rear area, failure to plan for or use a reserve, and limitations of their supply and communications lines. All the strength that the North Koreans had available was for the most part committed (with some insignificant exceptions at Inch'on) against the Eighth Army. North Korea did not expect the assault to its rear area nor did it have sufficient resources available to counter the US/UN operations. MacArthur's estimates of the North Korean forces and their capabilities were sufficiently accurate to plan a decisive, tactical battle.

The US/UN strategic goal was to stop the North Koreans and end the conflict decisively. This objective was not completely achieved even though the majority of the tactical battles were won. The operation only temporarily halted the North Korean aggression against the south. Operation Chromite resulted in rendering the North Korean forces combat ineffective for the immediate future, but also brought about the eventual entry of the Communist Chinese forces. The North Korean goals and their future were now in the hands of the Chinese Army forces and advisors of the USSR. Ultimately, this led to stalemate rather than victory for the US/UN.



General MacArthur was the heart and soul of the operation from its birth as an idea through the fight to bring it to full term and to its full execution. He used his staff for the detailed planning and to bring the plan to life. He did not waiver nor concern himself with the objections of his advisors. No issue or difficulty in the execution of operation swayed him. Operation Chromite effectively used depth of battle to turn the enemy from its position of preparedness and destroy its ability to sustain future major operations. MacArthur made use of his firepower to reach multiple areas across the depth of the area of operation in order to disrupt and fix the enemy. Amphibious operations were difficult enough to plan and execute during this period; combining this action with the necessary air support and a separate ground operation using resources from separate services was a monumental feat of planning and coordination. He tailored his forces to accomplish the objective. He made effective use of the forces available to him by pulling resources from around the theater and from the South Korean Army. He shifted forces and personnel between branches and organizations to fill the needs of the mission. This operation provides the military with an example of how joint and combined operations can be conducted to mutually support an overall objective.

Final Word

Invasion route for InchonCredit: US Marine Operations in Korea, Vol II, uploaded 2005

As discussed in this article, tactical level operations were very successful: however, in spite of all his best efforts, achievement of the US/UN strategic goal to stop all forms of Communism and its spread had failed. Instead of stifling the spread of Communism, the war brought 

about the entrance of the Communist Chinese into the conflict, propelling the US/UN into a longer and more uncertain future. The operation does provide, however, an outstanding example of a successful joint and combined arms operation. Operation Chromite was a complete operation requiring, the synchronization and coordination of multiple services to accomplish a major, tactical goal.

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