Risk vs. Reward: The Operational Art at Inchon
“We drew up a list of every conceivable and natural handicap and Inchon had ‘em all.”
-- Rear Admiral James Doyle, Operation Chromite Amphibious Force Commander
By September 1950, the United Nations (UN) and South Korean forces were between a rock and a hard place inside the Pusan Perimeter, with the Sea of Japan to the east, the Korea Strait to the south, and the Korean People’s Army (KPA) moving aggressively from the north. The difference between success or failure on the Korean Peninsula fell on the shoulders of the theater commander, US Army General Douglas MacArthur. His decision to execute Operation Chromite, a bold, combined arms, amphibious landing on the Korean west coast at Inchon, turned the tide of the war. Chromite successfully prevented a defeat at the Pusan Perimeter while cutting off vital North Korean lines of supply and communication through an amphibious envelopment. In order to understand the operational art and dynamics of Chromite’s success, it is necessary to frame the problem through a Cold War perspective militarily and politically, analyze the defense of the Pusan Perimeter to the planning and execution of Chromite, and evaluate how the operation successfully met strategic objectives through the creative and skillful employment of military forces while balancing the ends, ways, means, and risk.
The Cold War Context
Thinking critically about actions on the Korean Peninsula in the early 1950s, it is important to remember that the majority of the world was still recovering from a world war which left many nations barely functioning. The US military was in the early stages of the Cold War with an evolving organizational structure, understrength units, and undertrained troops spread across the globe. Compounding the problems of troop numbers and quality of training, the late-1940s military utilized a mixed arsenal with antique weaponry from World War II to newly developed nuclear-capable systems. The US military was struggling to find where it fit in the global order while trying to prevent the spread of communism and nuclear war. As North Korean forces moved aggressively down the Korean Peninsula, the world soon realized “that a small, little-known country could achieve military success against a coalition that included this, the world’s most powerful nation.” Thus, a war against a determined enemy began at a time when US preparedness--both militarily and politically--was in question.
Still in its infancy, the Cold War drove early organizational changes to the military in an attempt to implement a nuclear arsenal down to the tactical level. MacArthur viewed conflict on the Korean Peninsula in the Cold War context and understood the implications of failure to stop communism as it aggressively pushed south:
"The prestige of the Western world hangs in the balance. Oriental millions are watching the outcome. It is plainly apparent that here in Asia is where the Communist conspirators have elected to make their play for global conquest…Actually, we here fight Europe’s war with arms, while there it is still confined to words. If we lose the war to Communism in Asia, the fate of Europe will be gravely jeopardized."
Key to future involvement on the Korean Peninsula was the April 1950 release of National Security Council 68 (NSC-68). This document laid the groundwork for US foreign policy during the Cold War with an increase in the size of the military, more aid to allies, and hydrogen bomb development in an effort to prevent the spread of communism.
After the North Korean forces crossed the 38th Parallel in June 1950, the United States found itself in the first major conflict of the Cold War, with eventual support of North Korea from both the Soviet Union and the People’s Republic of China (PRC). Department of the Army staff informed Secretary of the Army Frank Pace that “There can be no doubt but that the invasion of South Korea is a planned Soviet move to improve their Cold War position at our expense.” Under NSC-68, the United States as the predominant force under the United Nations Command, entered the war in July 1950 to stop what many believed was the first step in the global spread of communism. At this time, it was difficult to discern if the Korean War would remain a localized conflict on the peninsula as a proxy war between the United States and the Soviet Union or if the fighting would expand to direct conflict between the two and their associated allies. Thus, creating a strategic dilemma of stopping communism’s spread in Northeast Asia while not losing focus on the increasing Cold War hostilities in Europe. As conflict on the Korean Peninsula progressed, the fighting took the shape of a limited war using World War II tactics but with the added threat of nuclear escalation and another world war.
Dire Defense of the Pusan Perimeter and Near Defeat: “Stand or Die”
The war between North and South Korea lasted three years, from June 1950 to July 1953. As the war developed, China and the Soviet Union provided support to the North and the United States and United Nations to the South. By September of 1950, South Korean and US forces fell back to the southeastern edge of the peninsula in an area called the Pusan Perimeter (See Figure 1). The perimeter was just under 150 miles long and created a defensive line around several cities and the port of Pusan with the preponderance of forces falling under the US Eighth Army. Numerous engagements occurred along this perimeter over the course of six weeks as the commander of the Eighth Army, Lieutenant General Walton Walker, reportedly told his division command post that “there will be no more retreating, withdrawal, or readjustment of the lines…There is no line behind us to which we can retreat…We are going to hold this line. We are going to win.” Walker believed that the Eighth Army “fights where it stands,” meaning retreat was not an option and the defense continued against countless KPA attacks with the assistance of the ROK Army, US Marines, and British forces.
The KPA mounted a massive offensive across the entirety of the Pusan Perimeter from the end of August into September when a desperate struggle by UN forces took place to prevent penetration of the line. The perimeter fluctuated by the day as the KPA punctured miles into the defensive belt, only be forced back by Walker’s expert use of interior lines to move reserves and supplies to threatened areas. Due to the over-extended KPA supply chain, the defenders within the Pusan Perimeter were able to hold while massing forces and supplies at the Pusan Port under MacArthur's direction. This calculated move set the stage for a counter-attack that regained the initiative by cutting off the attacking KPA force with a strike from the sea into the enemy’s rear-area at Inchon.
Operation Chromite: A Challenging Strike from the Sea
As the KPA continued to violently attack the Pusan Perimeter in an effort to end the war once and for all, MacArthur prepared an amphibious assault to cut off the southern-most KPA elements from vital supply lines running north up the peninsula. An envelopment to the northwestern coast at Inchon would place MacArthur’s forces in the North Korean rear-area within a short distance of the KPA held capital of South Korea known as Seoul. MacArthur continued preparations for Operation Chromite against all recommendations from his staff and the Joint Chiefs as they “expressed grave doubts about the wisdom of landing at Inchon, primarily because of the extremely high tides there, the narrow channel to the port, the drain on Eighth Army’s reserves, and the distance from Walker’s lines, which might result in a late link-up.”
Inchon presented countless challenges with even more developing as the planning process progressed. This was the point where most commanders would have altered course to a more feasible landing location or changed focus to a pure ground assault. Instead, MacArthur held firm against heavy opposition from his staff as he saw what many others refused to see. In his words, “the history of war proves that nine out of ten times an army has been destroyed because its supply lines have been cut off…We shall land at Inchon, and I shall crush them [the North Koreans].” MacArthur decided after only a week into the war that a strike deep into the enemy rear-area would cut off the extended KPA lines of supply and communication and shift momentum to the southern forces for retaking the peninsula. The design of Chromite intended to set an anvil at Inchon that Walker’s Eighth Army could hammer from the South, destroying the North Korean army in between.
MacArthur understood the current state of the war and the importance of seizing the South Korean capital of Seoul for “strategic, political, and psychological reasons.” Therefore, Chromite preparation continued with a plan to utilize the 1st Marine Division (MARDIV) under Major General Oliver Smith and the Army’s 7th Infantry Division (ID) under Major General David Barr. Only three weeks before the planned execution date for Chromite, MacArthur met with the Army and Navy chiefs and various senior level staff members from the Pentagon to review the findings and recommendations for a proposed amphibious landing. Here, Rear Admiral James Doyle, who would be the amphibious force commander for Chromite, presented details on Inchon tides, beaches, currents, channels, and ship-to-shore movements only to conclude that “the best I can say is that Inchon is not impossible.” MacArthur waited for everyone in the room to speak and clear their conscience, then he followed with an hour-long discussion on why the amphibious landing at Inchon would be the best option available to the United Nations Command and would certainly achieve surprise, as the enemy would never expect an attack from the sea to seize Seoul. Only days later, MacArthur received approval from the Joint Chiefs to continue preparations for Inchon with an additional requirement to either land or feint an assault on a secondary beach to the South.
Thus, planning continued for Chromite to execute a little more than two weeks away on September 15th, which was the earliest day that the tides would facilitate a landing of this size. MacArthur aligned the Chromite task organization under X Corps, commanded by his Chief of Staff, Major General Edward Almond. X Corps would include 7th ID, the half strength reserve out of Japan, and 1st MARDIV for the amphibious landing. To reach full strength in only a matter of weeks, the 7th ID received and trained nearly 9,000 South Korean personnel or “Koreans Attached [Augmented] to the US Army (KATUSAs)” that would partner with American Soldiers under a buddy system. 1st MARDIV encountered similar challenges preparing a combat-ready amphibious force with only a few weeks' notice but both units, along with a supporting complement of artillery and logistics, reached 71,300 troops among 260 ships under Joint Task Force 7’s commander, Vice Admiral Arthur Struble. X Corps received what many thought an impossible task of striking from the sea at Inchon to seize Seoul. This action would envelop the enemy attacking the Pusan Perimeter to cut off critical KPA lines of supply and communication, effectively relieving pressure on Walker’s Eighth Army and enabling an assault north out of the defense to link up with X Corps at Seoul while destroying any North Korean forces along the way.
At 0630 on September 15th, the initial wave from 1st MARDIV landed on a small island outside of Inchon named Wolmi-Do after days of aerial bombardment and the destruction of North Korean artillery batteries by American and British cruisers. Judging by the limited number of mines detected in the channel and relatively light KPA resistance, it would seem that “strategically and tactically, the North Koreans were caught by surprise.” With the tides quickly dropping the water level over 30 feet and revealing nearly three miles of mud from the Yellow Sea, the next wave of Marines would not approach until the evening tide came in. Over the next twenty-four hours, 1st MARDIV secured the initial objectives at Inchon with minimal casualties and began moving east towards Seoul while the Army’s 7th ID initiated offload on September 17th (See Figure 2).
The following battle for Seoul became more challenging than expected when the North Korean army diverted a division from the Pusan attack to reinforce Seoul. This change totaled a force of nearly 20,000 North Korean troops in and around Seoul, starting what evolved into an intense fight for the city. The Marines took heavy casualties, necessitating a split of 7th ID units to both attack Seoul and hold blocking positions to the South in order to prevent KPA reinforcements moving north from the Pusan Perimeter. Within two weeks, Seoul was secure with roughly 3,500 casualties from X Corps, and 14,000 North Korea troops killed with another 7,000 taken prisoner. Walker’s forces at the Pusan Perimeter did not initially achieve the expected breakout north after the Inchon landing but did manage to link up with elements of the 7th ID by the end of September. At this point the KPA “had ceased to exist as an effective army-size fighting force, and, though it would be reorganized later to fight alongside the Chinese Communist armies, its combat strength during the war never again would be more than a corps size.”
MacArthur’s Operational Art and the Chromite Strategy
Often thought of as challenging to conceptualize, operational art (OpArt) is difficult for many to grasp during an operation’s planning process. Beginning with the Clausewitzian viewpoint in which war is a continuation of politics by other means, OpArt uses the cognitive aspect of experience and creativity to connect strategic objectives to tactical actions in an effort to achieve desired military and political end-states. After much discussion about the post-Vietnam US military, the operational level of war evolved into an essential linkage between the strategic and tactical levels to bridge the gap from national and theater-level objectives to tactical actions on the battlefield (See Figure 3). Largely based on a concept used for centuries in Soviet military doctrine, the term “Operational Art” appears for the first time in the 1986 US Army Field Manual (FM) 100-5: Operations. FM 100-5 defines OpArt as the “employment of military forces to attain strategic goals in a theater of war…through the design, organization, and conduct of campaigns, and major operations.” Over thirty years later, Joint Publication (JP) 3-0: Joint Operations defines OpArt as the “cognitive approach by commanders and staffs supported by their skill, knowledge, experience, creativity, and judgment to develop strategies, campaigns, and operations to organize and employ military forces by integrating ends, ways, and means.” As OpArt attempts to use a non-prescriptive process to achieve military and political goals, difficulties arise when the end-states do not align. An example of conflicting military and political goals occurs later in the Korean War with the post-Inchon October offensive north of the 38th parallel that resulted in Chinese intervention on behalf of North Korea. Looking back at MacArthur’s actions leading up to Chromite, before the operational level of war and OpArt were more widely known and articulated, did MacArthur use OpArt successfully?
First, it is important to understand MacArthur’s strategy for Chromite to recognize his use of OpArt. Strategy is often defined as a “theory for success” where Bradford Lee’s four strategic concepts discuss focusing operations to deny the enemy something useful or needed, develop cost-imposing strategies for the enemy, attack the enemy’s strategy directly or indirectly, and/or attack the enemy’s political system. A good strategy does not require that all four of these methods be included, but a strategy that utilizes as many of these approaches as possible becomes more challenging for the enemy by increasing the level of complexity and effort required to overcome and win. MacArthur knew that Chromite would serve as a denial strategy by cutting off the KPA supply and communication lines to the southern force attacking the Pusan Perimeter. Additionally, Chromite would create a cost imposition for the North Korean forces by forcing them to fight on two fronts, thereby increasing friction and logistical strain. MacArthur chose to forgo a focused attack on the enemy’s political system. Instead, he opted to attack the enemy’s strategy directly by using a combined arms, amphibious envelopment to outmaneuver and destroy the KPA between Almond’s X Corps moving east from Inchon/Seoul and Walker’s Eighth Corps moving north out of the Pusan Perimeter defense. This strategy effectively caught the North Korean forces between MacArthur’s hammer and anvil when and where they least expected it.
MacArthur’s expert use of OpArt is evident in the way in which the operation surprised the KPA at Inchon, cut off supply lines to the KPA attack at the Pusan Perimeter, and created heavy losses for North Korea in between Seoul and Walker’s southern defense. JP 3-0 discusses the foundation of OpArt as encompassing a “broad vision; the ability to anticipate; and the skill to plan, prepare, execute, and assess.” MacArthur understood the need for a broad vision and to anticipate the enemy’s next move in order to outmaneuver them. To avoid a defeat at the Pusan Perimeter and a total loss of the Korean Peninsula, MacArthur knew a bold maneuver must take place to catch the enemy off guard, strike where least expected, and against all odds to effectively transition from the defense and regain the initiative.
The Army’s 2008 Training and Doctrine Command (TRADOC) Pamphlet 525-5-500, Commander’s Appreciation and Campaign Design, highlights how OpArt takes an unstructured problem and applies creativity, skill, and knowledge to design a strategy within the available time and space on the battlefield to reach the desired end-state. This TRADOC definition is useful in understanding how MacArthur embraced OpArt by encouraging an open dialogue regarding all the assumptions and risk factors surrounding Chromite with his staff and other elements of the joint force. This fluid discussion with open collaboration and debate led to a fine-grained understanding and framing of the problem at hand. Thus, planners and senior leaders eventually understood the problem from MacArthur’s perspective and the necessity for immediate action.
Additionally, Chromite presents an example of US Air Force Colonel John Boyd’s OODA Loop. The OODA loop, if applied correctly, creates an advantage by outpacing the enemy’s decision cycle, which frustrates them to a point of psychological defeat through speedy decisive military action. MacArthur utilized this process at Inchon with thorough Observation and Orientation of the problem followed by an unfettered Decision and immediate Action. MacArthur’s OpArt created an advantage by limiting North Korean options with the severing of the lines of support and communication at Seoul, and cognitively overwhelming the KPA by forcing them to adjust to changing battlefield dynamics.
Evaluation of Chromite’s Ends, Ways, Means, and Risk
Balancing the ends, ways, means, and risk of an operation is essential to successful OpArt. MacArthur clearly laid out the ends or desired end-state of destroying the North Korean forces between Seoul and Pusan with X Corps from the northwest and Walker’s Eighth Army from the south at Pusan. For the ways, he insisted with unbending certainty on a bold amphibious landing at Inchon to catch North Korean forces by surprise at a location that most thought impossible for a strike from the sea. The means involved a joint force with over 70,000 troops, 260 ships, and an extensive logistics plan to facilitate the continuous flow of forces and supplies from ship-to-shore.
As for risk assessment and mitigation, Chromite presented a significant risk to the mission and the force. The countless challenges of landing at Inchon drew substantial concerns from senior leaders and the Joint Staff. JP 3-0 states that risk management is a “function of command and a key planning consideration [that] helps commanders preserve lives and resources; avoid, eliminate, or mitigate unnecessary risk.” MacArthur and his staff, along with the subordinate commanders of the joint force, examined the problem set presented at Inchon in excruciating detail in an effort to eliminate or mitigate as much risk as possible. At the conclusion of Chromite planning, MacArthur acknowledged:
"If my estimate is inaccurate and should I run into a defense with which I cannot cope, I will be there personally and will immediately withdraw our forces before they are committed to a bloody setback. The only loss then will be my professional reputation. But Inchon will not fail. Inchon will succeed. And it will save 100,000 lives."
As the senior commander driving the idea of an amphibious landing to seize the initiative on the Korean Peninsula, MacArthur understood he would take full responsibility for the associated risk at Inchon and that with the possibility of a high reward came increased risk.
While the enemy always has a vote and the fog of war can make subsequent decisions challenging, the success at Inchon demonstrated expert balancing of the available means with the ways chosen to reach the desired ends, all while never losing focus on the risk involved. With only weeks to prepare and analyze the terrain, logistics limitations, and friendly force capabilities within the overarching political realities of a limited war in a Cold War context, the operation was a stunning military success. Shortly after the landing at Inchon, the Joint Staff messaged MacArthur saying that “your transition from defensive to offensive operations was magnificently planned, timed, and executed…We remain completely confident that the great task entrusted to you by the United Nations will be carried to a successful conclusion.” As commander of the United Nations force, MacArthur fought the Korean War with “limitations on armed conflict under the shadow of a nuclear holocaust,” where a misstep or wrong move could escalate into a much larger conflict with the Soviet Union or China. He carefully considered the military risk involved while being willing to accept losing ground politically. The desired military and political ends drove the decision to execute Chromite, but post-Inchon actions, although necessary, created political discourse as China warned that they “will not tolerate foreign aggression and will not stand aside should the imperialists wantonly invade the territory of their neighbor.” MacArthur demanded a North Korean surrender on the 1st of October with no official response.  By early October, ROK forces and eventually United Nations forces assaulted north of the 38th parallel bringing about the promised support of North Korea by China.
Conclusion / Final Analysis
When planning Operation Chromite, MacArthur understood that defeat on the Pusan Perimeter and losing the Korean Peninsula was a potential reality. US Soldiers and Marines, along with the ROK Army and British forces, desperately held the last piece of ground on the Korean Peninsula against an aggressive KPA that was on track to achieve its goal of winning the war by September 1950. MacArthur knew after only a week into the Korean War that an amphibious operation was necessary to strike deep into the enemy’s rear-area and cut off the communications center at Seoul. MacArthur demonstrated the ability to expertly transition from the defense at Pusan to regain the offensive through a combined arms amphibious envelopment at Inchon. This maneuver eliminated North Korea’s ability to present an effective fighting force above the corps level for the remainder of the war without direct support from China. Therefore, Operation Chromite provides a bookmark in history as one of the first true displays in the Cold War where actions speak louder than words as a United Nations force chose to risk near defeat and significant loss of life to stop the spread of communism on the Korean Peninsula.
Through creativity and persistence, MacArthur's operational art set the framework for Chromite in a zero-sum environment where failure at the Pusan Perimeter was not an option, and a strike from the sea at Inchon was the only acceptable course of action. With Cold War implications looming over every action on the Korean Peninsula, it was paramount to correctly balance the ends, ways, means, and risk for Chromite from the strategic level to tactical employment of forces. MacArthur understood the cost of failure but, more importantly, never lost sight of the reward from success at Inchon. He proceeded to remove any variables or resistance that stood in the way while maintaining operational flexibility for subordinate commanders during execution. MacArthur’s operational art and ultimately his leadership enabled an aggressive and unexpected strike deep into the enemy rear-area that ultimately changed the outcome of the war.
"No operation in military history can match either the delaying action where you traded space for time in which to build up your forces, or the brilliant maneuver which has now resulted in the liberation of Seoul."
-- President Truman to General MacArthur on his Operational Art after Operation Chromite
 Ibid., 467.
 Roy E. Appleman, South to the Naktong, North to the Yalu (Washington DC: Office of the Chief of Military History, Department of the Army, 1961), vii.
 James D. Clayton, The Years of MacArthur: Vol. III, 470.
 Paul G. Pierpaoli, Truman and Korea: The Political Culture of the Early Cold War (Columbia: University of Missouri Press, 1999), 25-26.
 James Schnabel, Policy and Direction: The First Year. Vol 3 (Washington, DC: Office of the Chief of Military History, US Army, 1972), 75.
 Ibid., 446.
 Roy E. Appleman, South to the Naktong, 252.
 James D. Clayton, The Years of MacArthur: Vol. III, 446.
 Ibid., 448.
 Ibid., 466.
 Roy E. Appleman, South to the Naktong, 488.
 Ibid., 493.
 Ibid., 493.
 Robert D. Heinl, “The Inchon Landing: A Case Study in Amphibious Planning.” Naval War College Review, 85, no 2 (1998), 124.
 Roy E. Appleman, South to the Naktong, 493.
 Ibid., 494.
 James D. Clayton, The Years of MacArthur: Vol. III, 466.
 Ibid., 471 - 472.
 Ibid., 475.
 Ibid., 480.
 Ibid., 480.
 Ibid., 482.
 Clayton Newell and Michael Krause, On Operational Art (Washington DC: Center of Military History, United States Army, 1994), iii.
 Headquarters Department of the Army, Operations, FM 100-5 (Washington, DC: Headquarters Department of the Army, May 1986) 10.
 US Joint Chiefs of Staff, Joint Operations, JP 3-0 (Washington, DC: US Joint Chiefs of Staff, January 2017) II-3.
 Bradford A. Lee, “Strategic Interaction: Theory and History for Practitioners,” in Competitive Strategies for the 21st Century: Theory, History, and Practice, ed. Thomas G. Mahnken (Palo Alto: Stanford University Press, 2012), 28.
 US Joint Chiefs of Staff, Joint Operations, II-3.
 Ibid., II-5.
 Ibid., III-19.
 James D. Clayton, The Years of MacArthur: Vol. III, 484.
 Ibid., 484.
 James Schnabel, Policy and Direction: The First Year. Vol 3, vii.
 Roy E. Appleman, South to the Naktong, 608.
 Ibid., 609, 615.
 Ibid., 488.
 James D. Clayton, The Years of MacArthur: Vol. III, 482.
 Ibid., 484.
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Heinl, Robert D. “The Inchon Landing: A Case Study in Amphibious Planning.” Naval War College Review, 85, no 2 (1998): 117 – 134.
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