The January 2015 issue of Armchair General® presented the Combat Decision Game “Marines at Pusan Perimeter, Korea, 1950.” This CDG placed readers in the role of U.S. Marine Corps Captain Ike Fenton, commander of B Company, 1st Battalion,5th Marine Regiment, 1st Marine Provisional Brigade, during the early months of the Korean War. Fenton’s mission on August17, 1950, was to lead an attack to seize and hold key terrain on Obong-Ni Ridge that was being occupied by North Korean forces.

Almost two months earlier, on June 25, 1950, 230,000 North Korean People’s Army (NKPA) troops, led by a brigade of Soviet-built T-34 tanks, launched an invasion across the 38th parallel that divided communist North Korea from democratic South Korea (Republic of Korea, or ROK). The 65,000- man ROK army proved no match for the NKPA invaders, and even the commitment of U.S. ground troops in July disastrously failed to stop the enemy advance.

By the beginning of August, the North Korean offensive had pushed General Walton Walker’s U.S. 8th Army, consisting of ROK and U.S. forces, into a 90-by-60-mile enclave near Pusan at the southeastern tip of the Korean peninsula. Holding the “Pusan perimeter” was vital, as this would give General of the Army Douglas MacArthur the time he needed to mobilize, train and equip the forces necessary to mount a devastating counterstroke to defeat the NKPA invasion and save South Korea.

By mid-August, however, Walker’s hard-pressed troops were barely maintaining a tenuous hold on the Pusan perimeter defensive line. Moreover, further enemy attacks had forced a dangerous “bulge” in the perimeter’s southwestern sector by seizing a bridgehead across the Naktong River. From there, the NKPA forces were in a position to strike east toward the vital port of Pusan, whose capture would have collapsed Walker’s entire defense.

Fenton’s attack was a crucial operation to stop the NKPA forces from expanding the Naktong bridgehead, thereby preventing them from seizing Pusan and collapsing the Pusan perimeter defense.

HISTORICAL OUTCOME Fenton decided that to give his company the best chance for success, he needed to concentrate his attack on the northern tip of the enemy-held Obong-Ni Ridge and then roll up the NKPA defenses one by one from north to south (COURSE OF ACTION ONE: RIGHT HOOK). Hitting the enemy from the flank also had the advantage of keeping Fenton’s attacking Marines well out of the line of fire from the company’s supporting mortar, artillery and machine guns, allowing these weapons to freely blast the NKPA positions along the ridge without fear of hitting friendly troops. Moreover, the flank attack restricted the enemy’s ability to bring to bear all of its defending troops and supporting firepower against the Marines.

As rounds from mortars, artillery and machine guns hit NKPA positions all along the ridge, B Company’s 1st Platoon led the attack, closely followed by 2d Platoon. After the assault began to bog down at the first objective, Hill 102, Fenton committed 3d Platoon as reinforcements. This provided the combat power the company needed to take the hill, and soon afterward Fenton’s men captured the second objective, Hill 109. But once the Marines had seized the ridge, they still had to hold it.

Throughout the night of August 17-18, 1950, masses of NKPA troops counterattacked to regain the key terrain. Fenton’s Marines held the ridge, but they paid a stiff price. On August 17, B Company had gone into the line with five officers and 190 men; 24 hours later, Fenton was the only officer left, and just 88 of the company’s Marines remained combat effective (and many of those were “walking wounded” who refused medical evacuation).

Shortly after the fight for Obong-Ni Ridge, famed photojournalist David Douglas Duncan visited Captain Fenton’s company, which was still holding the Naktong River line against repeated NKPA attacks. Duncan took a haunting photograph of the physically exhausted and emotionally drained Fenton that was published in the September 18, 1950, issue of Life magazine. The image is one of the most starkly compelling statements ever made about the toll that combat takes on those who must endure its ravages. (Good Read: 100 Greatest Military Photographs by Robert J. Dalessandro, Erin R. Mahan and Jerry D. Morelock; Whitman Publishing, 2013.)


ACG judges based their selections for winning Reader Solutions and those receiving honorable mention on submissions that chose COURSE OF ACTION ONE: RIGHT HOOK, or those whose explanations demonstrated a solid understanding of the key principles for a “seize and hold” attack. (See “After Action Report,” p. 66.) This plan concentrated B Company’s attacking forces against the most vulnerable sector of the enemy line, since the NKPA defenders were unable to bring to bear all of their men and supporting firepower against the company’s assault. Moreover, this option allowed the Marines to mass against the two principal objectives (Hill 102 and Hill 109) one at a time, thereby increasing the company’s chances of overwhelming each position’s defenders. Finally, this course of action made the best use of Fenton’s supporting firepower, which could fire freely at the entire ridge without fear of hitting friendly troops.

Since COURSE OF ACTION TWO: TWO PLATOONS ABREAST required supporting mortars, artillery and machine guns to fire over the heads of B Company’s advancing troops, it put the company at risk of incurring friendly-fire casualties and inhibited full use of supporting fire as the Marines closed on their objectives. Moreover, simultaneously attacking both hills prevented the Marines from massing overwhelming numbers against either one, thereby in  creasing the risk that the attack would fail to capture one, or perhaps both, of the key ridge-top positions.

COURSE OF ACTION THREE: THREE PLATOONS ABREAST essentially had the same disadvantages as COA Two, yet it also placed B Company at risk of incurring heavy casualties by exposing all of the company to the enemy’s full firepower as Fenton’s Marines advanced over open terrain. Therefore, even if the plan had succeeded and the Marines had seized the ridge, the company could have suffered such heavy casualties that it would have been left too weak to hold the ridge against subsequent NKPA counterattacks.

And now for excerpts from the winning Reader Solutions to “Marines at Pusan Perimeter, Korea, 1950.”

Deetlefs du Toit, South Africa: “Concentrate and maximize all support fire and close air attack in front of the advance. With accomplishment [of seizing the objective], consolidate position, resupply, and clear fields of fire, if possible, for all round defense. Clearly communicate new coordinates for defensive support fire.”

Michael Jevons, Hawaii: “I chose the right flank [plan] because the enemy is laid down linearly with most of his firepower oriented to the east. Deception is a goal, leading the enemy to believe the main attack will come from the east. A mixture of HE/smoke is used to conceal the battlefield movement.”

Colonel (Ret.) Dmytro Stepanenko, New York: “The best chance is to capitalize on speed, firepower and the restricted area along the top of the ridgeline while concentrating firepower. Once 1st Platoon shatters the enemy’s [northern] flank, use 2d Platoon to maintain the momentum.”

Thank you to everyone who participated in this CDG. Now turn to page 56 and test your tactical decision-making skills with CDG #68, “Israel’s War of Independence, 1948.” This action places you in the role of Major Moshe Dayan, an Israeli commander of a mixed force of local militia and Haganah (organized defense force) fighters, as several Arab armies invade the new nation of Israel in May 1948. Dayan’s mission is to defend positions on the southern shore of the Sea of Galilee against an attack by a much larger Syrian force of tanks, artillery and infantry. Use the CDG map and form on pages 59 and 60 to explain your solution, and then mail, email or fax it to Armchair General by April 24, 2015. Winners will be announced in the September 2015 issue, but those eager to read the historical outcome and analysis can log on to after April 27.

*Editor’s Note: For each Combat Decision Game, ACG typically receives numerous Reader Solutions that have selected the course of action that ACG judges have deemed the best COA for that CDG. However, our judges are required to choose winners and those earning an honorable mention from submissions whose explanations, in the judges’ opinion, best reflect an understanding of the principles and key points of the CDG’s tactical situation.


Originally published in the May 2015 issue of Armchair General.