Korean Lessons[764]
[764] Unless otherwise noted, the material in this section is derived from: PacFlt EvalRpts No. 4, Chaps. 9, 10, No. 5, Chaps. 1, 8, No. 6, Chaps. 1, 9; Generals’ Summary; Lessons Learned 5-53; 1stMarDiv PIR 942, dtd 7 Aug 53; 1st MAW PIR 127-53, dtd 7 May 53, Encl (1) Estimate of Enemy Ground Situation #1-53 (end-of-war analysis); 1st MAW PIR 169-53, dtd 18 Jun 53, Encl (1) Estimate of Enemy Air Situation 1-53, dtd 20 May 53 (end-of-war analysis); 5thMar ComdD, Nov 52, App. VI: Comments on Tactics, Techniques, and Equipment, pp. 1–12; J. Lawton Collins, War in Peacetime—The History and Lessons of Korea (Boston: Houghton Mifflin Co., 1969); S. L. A. Marshall, The Military History of the Korean War (New York: Franklin Watts, Inc., 1963); S. L. A. Marshall, Pork Chop Hill—The American Fighting Man in Action, Korea, Spring 1953 (New York: William Morrow & Co., 1956), quoted with permission of the publisher; Ridgway, Korean War; Hicks, Outpost Warfare; Batterton, Korea Notes.
In the early phase of the Korean War, the 1st Marine Division deployment was in a moving battle situation similar to numerous engagements it had fought in the past 175 years. Most of the “lessons” learned from the enemy, the tactical situation itself, and the terrain in Korea are derived largely from the later outpost warfare stage when the Marines were employed in a stabilized and sustained defensive situation similar to that facing other Allied units across the entire Eighth Army front. Tactics of defense on a wide front, construction of permanent type field fortifications, and organization of the battle position in difficult terrain was a new experience to Marines. This period of limited objective attacks and battles of attrition highlighted the importance of small unit tactics and demonstrated some modified concepts regarding employment of supporting arms.
During the period of outpost warfare, the 1st Marine Division was never confronted by a general enemy offensive or combined infantry-armor-artillery-air assault. The nature of the conflict was one of limited objective attacks, with strong and sometimes sustained probes. Typically, these were two-battalion assaults against a platoon-size outpost.
Time after time, as UNC defending troops learned, the CCF characteristic pattern of attack was repetitive and almost predictable. After dark, heavy preparatory fires deluged an isolated advance outpost. Crude, but effective, improvised demolitions often reduced COP fortifications[765] so that the enemy could assail the position. Waves of attacking Chinese then overwhelmed the greatly outnumbered defenders. Almost invariably the initial attack made on the front of the position was a feint; the real attack would be made by troops that had enveloped the position and moved to the rear. Enemy ambush forces were also located to the rear of the outpost, between the COP and MLR, at normal reinforcement routes to prevent both a pullback by the defenders to the MLR and to stop reinforcements from reaching the outpost.
[765] If the enemy advanced closer than 50 yards, by closely following under heavy preparatory fires, he could penetrate the position. At this close range, normal box-me-in artillery fires were not close enough to break up the attack. Lessons Learned 5-53, p. 10.
Effective defensive fire plans for the COPs covered all likely enemy approaches and assembly areas, as well as close-in boxing fires of the COP on all sides. Marine defense positions were sited for all-round defense, with special attention paid to covering the rear approaches at night. This tactic of rear envelopment also applied on a smaller scale to patrols. Invariably the CCF maneuvered to the flanks and rear of a friendly patrol in an attempt to encircle it. The CCF skillfully employed both the terrain and troops and regularly attacked from more than one direction.
Experience with Communist combat techniques forced UNC leaders to reevaluate their own night-fighting tactics. The Chinese had a marked superiority in night operations. Every major attack on Marine outposts during the last year of the war was made at night. When they were not directly assaulting a friendly site, the CCF advanced their own ground positions by digging and their well-known creeping tactics. This enabled them to establish an OP line within small arms and mortar range of Marine COPs and the MLR. The battle for Bunker Hill came about as a result of this enemy tactic. Organization in early 1952 of COP-2A, adjacent to the Panmunjom corridor, was in direct rebuttal to this same tactic. By such indirect methods, the Chinese were further able to extend their already favorable high ground positions which gave them observation over practically all of the Marine front line. Defensively the enemy used the cover of darkness equally well: mountain roads were aswarm with trucks and supply movements, which UNC night-fighters and bombers slowed with only moderate success.
Skilled, rapid construction of field fortifications and excellent camouflage discipline by the enemy were also object lessons. Entrances to tunnels and caves, as well as the bunkers themselves were so carefully disguised by fresh branches, weeds, logs, and other natural foliage that they were rarely visible either by air observer or aerial photographs. Active weapons positions were also effectively camouflaged. Often 60mm and 82mm mortars were housed in bunkers and fired through a narrow opening at the top. If moved out temporarily to an open slope, they were quickly returned to the bunker to avoid detection. The Chinese elaborate underground system of trenchworks and radial tunnels between forward and rear bunkers was sometimes as much as 35 yards long. Underground bunkers and tunnels often had 20 feet or more of protective dirt cover and offered security from anything except a direct aerial hit.
Destruction of the enemy’s trenches, bunkers, and cave network by medium and heavy artillery was only partially successful. Napalm was generally ineffective due to the lack of combustible materials in CCF ground defenses. The well-prepared, deeply dug fortifications were virtually impervious to anything less than air assaults with heavy ordnance (1,000-pound bombs and over) which were required to destroy CCF reverse slope positions.