The Pusan Perimeter
The North Korean army has almost driven UN forces into the peninsula’s southeastern corner, but it is stretched around a long front and difficult roads.
Battle
Inchon
15 — 19 September 1950
Tides and surprise reverse a front that seemed doomed.
Military history
How did a landing in a harbor judged hazardous cut off the army that was still advancing toward Busan?
Inchon was an amphibious gamble: tides, channels, and quays made the landing difficult, but those same constraints reduced the likelihood of a prepared defense on the correct axis. MacArthur gambled on surprise and depth rather than frontal strength at the Pusan Perimeter.
An unlikely landing
Inchon has extreme tides, muddy channels, and seawalls. These obstacles make the operation risky, but also lower the defender’s expectations.
Two fronts to coordinate
The plan paired an attack in the rear from Inchon with the Eighth Army’s renewed offensive from Pusan. Their effects reinforced one another, but coordination did not mean Inchon forces immediately joined those from Pusan or prevented every North Korean retreat.
The beaches were not interchangeable
Green Beach lies on Wolmi-do, forward of the port. Red Beach required scaling the seawall north of the city. Blue Beach, farther southeast, had different approaches and exits. The map keeps these three objectives separate and does not send every wave to one beach.
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Chronological dossier
Pusan PerimeterHow did the UN and South Korea stop retreating, supply their sectors through Busan and prevent local penetrations from joining before launching a counteroffensive?ChosinChinese forces encircle the Marines and American units, which open an escape route through cold and fire.Chipyong-niHow did an isolated perimeter break the momentum of a Chinese offensive by combining all-round defence, external fire support and a relief counterattack?Imjin RiverHow did a brigade dispersed across a broad front delay a Chinese offensive while risking the isolation of its battalions?Triangle HillWhy did a limited offensive for a few heights become a battle of attrition whose cost progressively exceeded the ground's value?
Military history
Sources
Contemporary sourceMontross et Canzona, The Inchon-Seoul Operation, volume II
Chapitres V–VIII, pp.85–119 et 149–164 : préparation, Wolmi-do, deux plages, Ascom, M26 et Kimpo. Cartes pp.99 et154 examinées entières.
Tide-window chronology, regimental roles, objectives and armored support. A retrospective source, not a standalone contemporary report.
View ↗War historyClay Blair, The Forgotten War
Chapitres sur Inchon et la rupture du périmètre de Pusan
Context, command, and consequences.
Official historyUS Army Center of Military History, The Korean War
Official naval history and mapsUS Naval History and Heritage Command, The Inchon Invasion
Dossier opérationnel sur le débarquement du 15 septembre 1950
Maps of Flying Fish Channel, Wolmi-do, tides, beaches, and the landing sequence.
View ↗U.S. Army official history, university copyRoy E. Appleman — The Landing at Inch’on, chapitre XXV
South to the Naktong, North to the Yalu, chapitre XXV : préparation, débarquement et section Capture of Kimpo Airfield and Advance to the Han River.
Cross-checking the plan, amphibious constraints, two tides and advance toward Kimpo; distinguishing the beachhead from later fighting.
View ↗Primary visual sources — contemporary U.S. Navy, Army and Marine Corps photographsInchon — Péniches, échelles et chars
Planches après p.68 : H-Hour, Hitting the Beaches, Advance to Force Beachhead Line et Inchon Secured. Quatre planches entières examinées.
Uniforms and helmets, wooden ladders, LCVP silhouette and tanks. Pose and color reconstructed; no individual serial number assigned.
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