Military commanders are responsible for planning operations and delegating tasks all the way to the tactical levels of combat, weighing mission-essential priorities, plotting troop schemes of maneuver, predicting enemy response, considering battle limitations, and seeing a mission through to its execution. The military commander’s vast experience and decision-making skills are both vital in leading Marines into a successful battlespace within a theatre of war. For centuries, the Marine Corps has played a crucial role in amphibious assaults, participating in numerous battles in major wars within the lines of traditional warfare. Joint Publication 1, The Doctrine for the Armed Forces of the United States, characterizes traditional warfare as the “defeat of an adversary’s armed forces, the destruction of an adversary’s war-making capacity, and/or the seizure or retention of territory.”[1]

In September 1950, Army General, Douglas MacArthur, Korean Theatre Commander, oversaw a combined arms campaign with United Nations allies that consisted of Marines from Fifth Battalion, First Marine Division, conducting a strategic, surprise amphibious landing on the beaches of Inchon, Korea, to aid their South Korean allies. As the theatre commander, General MacArthur had to weigh the potential risk of a surprise assault against the likelihood of a victory that would result in South Korea and the allied forces gaining an advantageous stance in the war. On studying and understanding the battle at Inchon, current and future warfighters can learn the importance of surprise as a key maneuvering battle principle, as combative elements of surprise not only have physical detrimental effects on the enemy, but also psychological effects as well, which, in combination, help contribute to the warfighter’s indispensable benefit.

To understand the combat role of surprise, its deterrent effect on the enemy, and its positive effects on the Korean War, it is important to be familiar with the political and cultural background that provoked the United States to come to South Korea’s aid. Starting in 1947, the United States was in a Cold War with the Soviet Union, in attempts to prevent the spread of communism and to deter nuclear aggression.[2] The Soviet Union, along with the People’s Republic of China (PRC), were allies with communist North Korea. North Korea and South Korea were divided by a boundary line, the 38th Parallel. In 1950, the North Koreans ignored the boundary, traversing into the south down the Pusan Perimeter into the Korean Peninsula in an attempt to spread communist ideologies and proclaim global dominance. General MacArthur’s well-planned amphibious assault at Inchon, also known within the United States as Operation Chromite, was the U.S. reaction to this “localized conflict,” which often is classified as a proxy war between the United States and Russia.[3]

General MacArthur received a great deal of criticism when he proposed that Marines should lead a surprise assault at Inchon, take back South Korean territories—including Seoul—and attack the North Korean flanks from behind.[4] General MacArthur said that the Marines would lead a “bold, combined arms” campaign that would cutoff North Korea’s communication and supply paths, while also preventing them from being able to seize the Pusan Perimeter.[5] General MacArthur received backlash, with critics warning him that a surprise landing at Inchon would not be feasible, given the location’s high oceanic tides and dangerous positioning. When analyzing MacArthur’s huge risk in executing a deceptive attack, history journalist Jeremy Blascak stated, “MacArthur understood the current state of the [Korean] war and the importance of seizing . . . Seoul for ‘strategic, political, and psychological reasons.’”[6] Blascak went on to argue that MacArthur wanted to take advantage of the opportunity to deceive the enemy through stealth and ambiguity; he weighed the risk associated with a surprise attack, and chose to follow through with it, as he believed the probability of success was too great to overlook.[7] Ultimately, on 15 and 16 September 1950, MacArthur’s risk paid off. With the help of important Marine Corps leaders such as Major General Oliver Smith, commander, First Marine Division, and heroic acts by Marines leading from the front such as First Lieutenant Baldomero Lopez, the Marines and UN forces were able to surprise, deter, and outwit the North Korean forces.

That being said, an important element of combat that puts the warfighter at a physical and psychological advantage over the enemy is deterrence, with can be a direct result of surprise. Joint Publication 1 defines deterrence as the “ability to influence potential adversaries not to take threatening actions” and that “deterrence is a state of mind brought about by the existence of a credible threat of unacceptable counteraction.”[8] Deterrence is the ultimate goal of combat, as it prohibits the enemy from engaging in retributive action and renders them unable to fight, as was the case with the North Koreans at the battle of Inchon.

One of the primary ways to achieve surprise is through deception.[9] Deception allows the enemy to behave in a manner that is “prejudicial to his own interests.”[10] In other words, deception is the warfighter’s ability to force the enemy to veer away from their intended plans, or to trick the enemy into believing one thing, with the warfighter purposefully and strategically performing another. For example, prior to Marine forces landing on the Inchon beaches, there were U.S. and South Korean forces cornered on all three sides of the Korean Peninsula by North Korean troops. Up until this point in the war, the South Koreans were at a severe disadvantage and were outnumbered.[11] North Korean forces were not expecting any enemy forces to attack their flanks from the rear. When the Marines attacked did precisely this, the North Koreans were ill-prepared; they had been deceived. Most likely, this deception affected the North Koreans’ ability to react and fight back, as this surprise battle did not align with their intended plans.

Ambiguity is another element of surprise that can throw off the enemy.[12] Warfighting: MCDP-1 describes the surprise element of ambiguity as acting “in such a way that the enemy does not know what to expect,” meaning the enemy is dealing in unknown territory, which places the them at a disadvantage.[13] To elaborate, the enemy loses the upper-hand because the warfighter forces itto operate from a defensive standpoint as opposed to an offensive one, which means all the enemy’s maneuvers will be reactive instead of proactive. In terms of the battle at Inchon, the North Koreans had to deal with a large degree of ambiguity while attempting to seize key areas south of the 38th Parallel, as they were unaware of the Marine Corps’ surprise attack. This ambiguity is what allowed UN forces to reclaim Seoul and move deeper into North Korean regions. An important element of surprise, ambiguity can cause time-sensitive delays in physical movements of troops and operations, while simultaneously creating confusion within the enemy force, which can lead to mistakes that negatively affect enemy performance.

Stealth is the third element that helps the warfighter achieve surprise in combat. Warfighting: MCDP-1 describes the exploitation of stealth as the ability “to deny the enemy any knowledge of impending action…the enemy is not deceived or confused of the [warfighter’s] intentions but is completely ignorant of them.”[14] In other words, the warfighter throws the enemy completely off guard, and the enemy is unclear of the warfighter’s current mission. Stealth played an important role in General MacArthur’s planning process, as he had to gather surveillance on the unaware enemy, and the Marines had to remain undetected as they maneuvered on land. Surprise tactics can force the enemy to be wholly unprepared, essentially incapacitating the enemy and its military capabilities.

Ultimately, General MacArthur’s bold, yet well thought-out decision to send Marine Corps forces to conduct Operation Chromite was successful because of the plan’s use of deception, ambiguity, and stealth. The surprise assault enabled the South Korean and U.S. forces to deter the North Koreans in the midst of battle, both physically and psychologically. This success enabled the South Koreans and their allied forces to gain a temporary advantage during the Korean conflict. In addition to seeing the positive effects the tactic of surprise had for the allied forces at Inchon Landing, General MacArthur’s willingness to accept the risks associated with the execution of a surprise assault reflect his boldness, judgment, and ability to take risks, all of which are requisite characteristics within a strong warfighter.

Endnotes

[1] Joint Chiefs of Staff, Joint Publication 1, Doctrine for the Armed Forces of the United States. 2013, Incorporating Change 1, 2017, pp.1-176.

[2] Jeremy Blascak,“Risk versus Reward: The Operational Art at Inchon,” Small Wars Journal, 8 November 2019.

[3] Blascak,“Risk versus Reward.”

[4] Blascak.

[5] Blascak.

[6] Blascak.

[7] Blascak.

[8] Joint Chiefs of Staff, Joint Publication 1, Doctrine for the Armed Forces of the United States. 2013, Incorporating Change 1, 2017, pp.1-176.

[9]U.S. Marine Corps, Warfighting MCDP-1,  U.S. Marine Corps, 1997. pp. 1-115.

[10] United States, Marine Corps. Warfighting MCDP-1.

[11] O’Connell, LtCol Aaron. “Keystone Battle Brief: Inchon Landing, Korea, 1950”. United States Marine Corps University, Marine Corps History Division, Accessed 2021.

[12] U.S. Marine Corps, Warfighting MCDP-1, U.S. Marine Corps, 1997. pp. 1-115.

[13] U.S. Marine Corps, Warfighting MCDP-1 .

[14] U.S. Marine Corps, Warfighting MCDP-1.