Battle of Inchon The Battle of Inchon ( , " Incheon Sangnyuk Jakjeon " ) was an amphibious invasion and battle of the Korean War that resulted in a decisive victory and strategic reversal in favor of the United Nations . The operation involved some 75 , 000 troops and 261 naval vessels , and led to the recapture of the South Korea capital Seoul two weeks later . The code name for the operation was Operation Chromite . The battle began on 15 September 1950 and ended on 19 September . Through a surprise amphibious assault far from the Pusan Perimeter that UN and South Korean forces were desperately defending , the largely undefended city of Incheon was secured after being bombed by UN forces . The battle ended a string of victories by the invading North Korean People ' s Army ( NKPA ) . The subsequent UN recapture of Seoul partially severed NKPA ' s supply lines in South Korea . The majority of United Nations ground forces involved were U . S . Marines , commanded by General of the Army Douglas MacArthur of the United States Army . MacArthur was the driving force behind the operation , overcoming the strong misgivings of more cautious generals to a risky assault over extremely unfavorable terrain . Background . Pusan Perimeter . From the outbreak of the Korean War following the invasion of South Korea by North Korea on 25 June 1950 , the North Korean Korean People ' s Army had enjoyed superiority in both manpower and equipment over South Koreas Republic of Korea Army and the United Nations forces dispatched to South Korea to prevent it from collapsing . The North Korean strategy was to aggressively pursue U . N . and South Korean forces on all avenues of approach south and to engage them , attacking from the front and initiating a double envelopment of both flanks of the defending units , which allowed the North Koreans to surround and cut off the opposing force , forcing it to retreat in disarray , often leaving behind much of its equipment . From their initial 25 June offensive to fights in July and early August , the North Koreans used this strategy to defeat any UN force they encountered and push it south . However , with the establishment of the Pusan Perimeter in August , the U . N . troops held a continuous line which the North Koreans could not flank , and their advantages in numbers decreased daily as the superior U . N . logistical system brought in more troops and supplies to the U . N . forces . When the North Koreans approached the Pusan Perimeter on 5 August , they attempted the same frontal assault technique on the four main avenues of approach into the perimeter . Throughout August , their military conducted direct assaults resulting in the Battle of Masan , the Battle of Battle Mountain , the First Battle of Naktong Bulge , the Battle of Taegu , and the Battle of the Bowling Alley . On the east coast of the Korean Peninsula , the South Koreans repulsed three North Korean divisions at the Battle of P ' ohang - dong . The North Korean attacks stalled as U . N . forces , well equipped and with large standing reserve units to draw upon , repeatedly repelled them . All along the front , the North Korean troops reeled from these defeats , the first time in the war North Korean strategy had failed . By the end of August the North Korean troops had been pushed beyond their limits and many of the original units were at far reduced strength and effectiveness . Logistic problems racked the North Korean army , and shortages of food , weapons , equipment , and replacement soldiers proved devastating for North Korean units . However , the North Korean force retained high morale and enough supply to allow for another large - scale offensive . On 1 September the North Koreans threw their entire military into one final bid to break the Pusan Perimeter , the Great Naktong Offensive , a five - pronged simultaneous attack across the entire perimeter . The attack caught U . N . forces by surprise and almost overwhelmed them . North Korean troops attacked Kyongju , surrounded Taegu and Ka - san , recrossed the Naktong Bulge , threatened Yongsan , and continued their attack at Masan , focusing on Nam River and Haman . However , despite their efforts , in one of the most brutal fights of the Korean War , the North Koreans were unsuccessful . Unable to hold their gains , the North Korean army retreated from the offensive a much weaker force , and vulnerable to counterattack . Planning . Days after the beginning of the war , General of the Army Douglas MacArthur , the U . S . Army officer in command of all U . N . forces in Korea , envisioned an amphibious assault to retake the Seoul area . The city had fallen in the first days of the war in the First Battle of Seoul . MacArthur later wrote that he thought the North Korean army would push the Republic of Korea Army back far past Seoul . He also said he decided days after the war began that the battered , demoralized , and under - equipped South Koreans , many of whom did not support the South Korean government put in power by the United States , could not hold off the North Korean forces even with American support . MacArthur felt that he could turn the tide if he made a decisive troop movement behind enemy lines , and preferred Incheon over Chumunjin - up or Kunsan as the landing site . He had originally envisioned such a landing , code named Operation Bluehearts , for 22 July , with the U . S . Armys 1st Cavalry Division landing at Inchon . However , by 10 July the plan was abandoned as it was clear the 1st Cavalry Division would be needed on the Pusan Perimeter . On 23 July , MacArthur formulated a new plan , Operation Chromite , calling for an amphibious assault by the U . S . Armys 2nd Infantry Division and the United States Marine Corps s 5th Marine Regiment in mid - September 1950 , but this , too fell through as both units were moved to the Pusan Perimeter as well . MacArthur decided instead to use the U . S . Armys 7th Infantry Division , his last reserve unit in East Asia , to conduct the operation as soon as it could be raised to wartime strength . In preparation for the invasion , MacArthur activated the U . S . Armys X Corps to act as the command for the landing forces , and appointed Major General Edward Almond , his chief of staff , as corps commander , anticipating the operation would mean a quick end to the war . Throughout August , MacArthur faced the challenge of re - equipping the 7th Infantry Division as it had sent 9 , 000 of its men to reinforce the Pusan Perimeter and was far understrength . He also faced the challenge that the U . S . Marine Corps , reduced in size following World War II , had to rebuild the 1st Marine Division , using elements of the 1st Provisional Marine Brigade fighting at Pusan as well as the 1st Marine Regiment and the 7th Marine Regiment , which pulled U . S . Marines from as far away as the Mediterranean Sea to Korea for the task . MacArthur ordered Korean Augmentation To the United States Army ( KATUSA ) troops , South Korean Army conscripts assigned to U . S . Army units , to reinforce the 7th Infantry Division , while allocating all equipment coming into Korea to X Corps , despite it being crucially needed by the U . S . Armys Eighth Army on the front lines . MacArthur decided to use the Joint Strategic and Operations Group ( JSPOG ) of his United States Far East Command ( FECOM ) . The initial plan was met with skepticism by the other generals because Incheon ' s natural and artificial defenses were formidable . The approaches to Incheon were two restricted passages , which could be easily blocked by naval mine s . The current of the channels was also dangerously quick – three to eight knots ( 3 . 5 to 9 . 2 mph ; 5 . 5 to 14 . 8 km / hr ) . Finally , the anchorage was small and the harbor was surrounded by tall seawall s . United States Navy Commander Arlie G . Capps noted that the harbor had " every natural and geographic handicap . " U . S . Navy leaders favored a landing at Kunsan , but MacArthur overruled these because he did not think they would be decisive enough for victory . He also felt that the North Koreans , who also thought the conditions of the Incheon channel would make a landing impossible , would be surprised and caught off - guard by the attack . On 23 August , the commanders held a meeting at MacArthur ' s headquarters in Tokyo . Chief of Staff of the United States Army General Joseph Lawton Collins , Chief of Naval Operations Admiral Forrest Sherman , and United States Air Force operations deputy Lieutenant General Idwal H . Edward all flew from Washington , D . C . , to Japan to take part in the briefing ; Chief of Staff of the United States Air Force General Hoyt Vandenberg did not attend , possibly because he " did not want to legitimize an operation that essentially belong [ ed ] to the Navy and the Marines . " The Marine Corps staff , who were to be responsible for leading the landing at Incheon , were not invited , which became a contentious issue . During the briefing , nine members of the staff of U . S . Navy Admiral James H . Doyle spoke for nearly 90 minutes on every technical and military aspect of the landing . MacArthur told the officers that though a Kunsan landing would bring a relatively easy linkup with the Eighth Army , a landing there " would be an attempted envelopment that would not envelop " and would place more troops in a vulnerable pocket of the Pusan Perimeter . MacArthur won over Sherman by speaking of his affection for the U . S . Navy and relating the story of how the Navy carried him out of Corregidor to safety in 1942 during World War II . Sherman agreed to support the Incheon operation , leaving Doyle furious . Despite these obstacles , in September MacArthur issued a revised plan of assault on Incheon : Plan 100 - B , codenamed Operation Chromite . MacArthur spent 45 minutes after the briefing explaining his reasons for choosing Incheon . He said that because it was so heavily defended , the enemy would not expect an attack there , that victory at Incheon would avoid a brutal winter campaign , and that , by invading a northern strong point , U . N . forces could cut off North Korean lines of supply and communication . He also chose Incheon because of its proximity to Seoul . Admiral Sherman and General Collins returned to Washington , D . C . , and had the invasion approved . The landing at Incheon was not the first large - scale amphibious operation since World War II . That distinction belonged to the 18 July 1950 U . N . landing at Pohang , South Korea . However , that operation was not made in enemy - held territory and was unopposed . Prelude . Before the main land battle , U . N . forces landed spies in Incheon and bombarded the citys defenses via air and sea . U . N . forces also conducted deception operations to draw enemy attention away from Incheon . Maintaining surprise . With men , supplies , and ships obviously concentrating at Pusan and in Japanese ports for a major amphibious operation and the press in Japan referring to the upcoming landings as " Operation Common Knowledge , " the U . N . command feared that it would fail to achieve surprise in the Incheon landings . Exacerbating this fear , the leader of a North Korean - Japanese spy ring arrested in Japan in early September 1950 had a copy of the plan for Operation Chromite , and the U . N . forces did not know if he had managed to transmit the plan to North Korea before his arrest . U . S . Navy patrol aircraft , surface warship s , and submarine s operated in the Sea of Japan and the Yellow Sea to detect any reaction by North Korean , Soviet , or People ' s Republic of China military forces , and on 4 September 1950 United States Navy F4U Corsair fighters of Fighter Squadron 53 ( VF - 53 ) aboard the aircraft carrier shot down a Soviet Air Force A - 20 Havoc bomber after it opened fire on them over the Yellow Sea as it flew toward the U . N . naval task force there . In order to ensure surprise during the landings , U . N . forces staged an elaborate deception operation to draw enemy attention away from Incheon by making it appear that the landing would take place 105 miles ( 169 km ) to the south at Kunsan . On 5 September 1950 , aircraft of the United States Air Force s Far East Air Forces began attacks on roads and bridges to isolate Kunsan , typical of the kind of raids expected prior to an invasion there . A naval bombardment of Kunsan followed on 6 September , and on 11 September U . S . Air Force B - 29 Superfortress bombers joined the aerial campaign , bombing military installations in the area . In addition to aerial and naval bombardment , U . N . forces took other measures to focus enemy attention on Kunsan . On the docks at Pusan , United States Marine Corps officers briefed their men on an upcoming landing at Kunsan within earshot of many Koreans , and on the night of 12 – 13 September 1950 the Royal Navy frigate landed United States Army special operations troops and Royal Marine Commando s on the docks at Kunsan , making sure that enemy forces noticed their visit . U . N . forces conducted a series of drills , tests , and raids elsewhere on the coast of Korea , where conditions were similar to Inchon , before the actual invasion . These drills were used to perfect the timing and performance of the landing craft , but also were intended to confuse the North Koreans further as to the location of the invasion . Incheon infiltration . Fourteen days before the main attack on Incheon , a joint Central Intelligence Agency – military intelligence reconnaissance effort , codenamed Trudy Jackson , placed a team in Incheon Harbor . The group , led by U . S . Navy Lieutenant Eugene F . Clark , landed at Yonghung - do , an island in the mouth of the harbor . From there , they relayed intelligence back to U . N . forces . With the help of locals , Lieutenant Clark , Republic of Korea Navy Lieutenant Youn Joung , and former South Korean counterintelligence officer Colonel Ke In - Ju gathered information about tides , beach composition , mudflat s , and seawalls . The tides at Incheon have an average range of 29 feet ( 8 . 8 meters ) and a maximum observed range of 36 feet ( 11 meters ) , making the tidal range there one of the largest in the world and the littoral maximum in all of Asia . They observed the tides at Inchon for two weeks and discovered that American tidal charts were inaccurate , but , fortunately , Japanese charts were quite good . They provided detailed reports on North Korean artillery positions and fortification s on the island of Wolmido , at Incheon , and on nearby islands . During the extensive periods of low tide they located and removed some enemy naval mines , but , critically to the future success of the invasion , Clark reported that the North Koreans had not in fact systematically mined the channels . When the North Koreans discovered that the agents had landed on the islands near Inchon , they made multiple attacks , including an attempted raid on Yonghung - do with six junks . Clark mounted a machine gun on a sampan and sank the attacking junks . In response , the North Koreans killed perhaps as many as 50 civilians for helping Clark . Bombardments of Wolmido and Incheon . On 10 September 1950 , five days before the Inchon landing , 43 American warplanes flew over Wolmido , dropping 93 napalm canisters to “ burn out ” its eastern slope in an attempt to clear the way for American troops . The flotilla of ships that landed and supported the amphibious force during the battle was commanded by U . S . Navy Vice Admiral Arthur D . Struble , an expert in amphibious warfare . Struble had participated in amphibious operations in World War II , including the Normandy landings and the Battle of Leyte . He got underway for Incheon in his flagship , the heavy cruiser , on 12 September 1950 . As the landing groups neared , cruiser s and destroyer s from the United States and Canada shelled the fortifications on Wolmido and checked for mines in Flying Fish Channel . The first Canadian forces entered the Korean War when the Royal Canadian Navy destroyers HMCS " Cayuga " , HMCS " Athabaskan " , and HMCS " Sioux " bombarded the coast . The U . N . Fast Carrier Force offshore flew fighter cover , interdiction , and ground attack missions . Hundreds of Korean civilians were killed in these attacks on the lightly defended port . At 07 : 00 on 13 September , the U . S . Navys Destroyer Squadron Nine , headed by the destroyer , steamed up Eastern Channel and into Incheon Harbor , where it fired upon North Korean gun emplacements on Wolmido . The attacks tipped off the North Koreans that a landing might be imminent , and the North Korean officer in command on Wolmido assured his superiors that he would throw the enemy back into the sea . North Korean artillery returned fire , inflicting significant damage on three of the attacking warships , killing one U . S . Navy sailor and wounding six others . The destroyer received the most damage ; she took nine 75 - millimeter - shell hits , which wounded five men . The destroyer sustained three shell hits resulting in light damage and no casualties . The one dead man , David H . Swenson from the destroyer , was later reported by the world media as being the nephew of Captain Lyman Knute Swenson , USS " Lyman K . Swenson " s namesake , but this was later found to be false . Between them , the Canadian and American destroyers fired over a thousand 5 - inch ( 127 - mm ) shells , inflicting severe damage on Wolmidos fortifications . The American destroyers withdrew after bombarding Wolmido for an hour and " Rochester " , the U . S . Navy heavy cruiser , and the British Royal Navy light cruiser s and proceeded to bombard the North Korean batteries for the next three hours from the south of the island . Lieutenant Clark and his South Korean squad watched from hills south of Incheon , plotting locations where North Korean machine guns were firing at the U . S . ships . They relayed thus information to the invasion force via Japan in the afternoon . During the night of 13 – 14 September , Vice Admiral Struble decided on another day of bombardment , and the destroyers moved back up the channel off Wolmido on 14 September . They and the cruisers bombarded the island again that day , and planes from the carrier task force bombed and strafed it . At 00 : 50 on 15 September 1950 , Lieutenant Clark and his South Korean squad activated the lighthouse on the island of Palmido . Later that morning , the ships carrying the amphibious force followed the destroyers toward Incheon and entered Flying Fish Channel , and Marines of the invasion force got ready to make the first landings on Wolmido . Battle . Green Beach . At 06 : 30 on September 15 , 1950 , the lead elements of X Corps hit " Green Beach " on the northern side of Wolmido . The landing force consisted of the 3rd Battalion , 5th Marine Regiment , led by Lieutenant Colonel Robert Taplett and nine M26 Pershing tanks from the U . S . Marine Corps 1st Tank Battalion . One tank was equipped with a flamethrower and two others had bulldozer blade s . The battle group landed from tank landing ships ( LSTs ) . The entire island was captured by noon at the cost of just 14 casualties . The North Korean forces were outnumbered by more than six to one by the U . N . troops . North Korean casualties included over 200 killed and 136 captured , primarily from the 918th Artillery Regiment and the 226th Independent Marine Regiment . The forces on Green Beach had to wait until 19 : 50 for the tide to rise , allowing another group to land . During this time , extensive shelling and bombing , along with anti - tank mines placed on the only bridge , kept the small North Korean force from launching a significant counterattack . The second wave came ashore at " Red Beach " and " Blue Beach " . The North Korean army had not been expecting an invasion at Incheon . After the storming of Green Beach , the NKPA assumed ( probably because of deliberate American disinformation ) that the main invasion would happen at Gunsan . As a result , only a small force was diverted to Incheon . Even those forces were too late , and they arrived after the UN forces had taken Blue Beach and Red Beach . The troops already stationed at Incheon had been weakened by Clark ' s guerrillas , and napalm bombing runs had destroyed key ammunition dumps . In total , 261 ships took part . For Red Beach and Blue Beach , Vice Admiral James H . Doyle , Commander of an Amphibious ready group , announced that H - Hour , time of landing , would be 17 : 30 . The North Korean 22nd Infantry Regiment had moved to Inch ’ on before dawn on September 15 , 1950 , but retreated to Seoul after the main landing that evening . Red Beach . The Red Beach forces , made up of the Regimental Combat Team 5 , which included the 3rd Battalion of the Republic of Korea Marine Corps ( ROKMC ) , used ladders to scale the sea wall s . Then - Lieutenant Colonel Raymond L . Murray ' s , served as Commanding Officer of the 5th Marines , mission was to seize an area three thousand yards long and a thousand yards deep , extending from Cemetery Hill ( northern ) at the top down to the Inner Tidal Basin ( near Tidal Basin at the bottom ) and including the promontory in the middle called Observatory Hill . ( See Map ) The 1st Battalion would be on the left , against Cemetery Hill and northern half of Observatory Hill . The 2nd Battalion would take the southern half of Observatory Hill and Inner Basin . Late on the afternoon of September 15 , the LSTs closed Red Beach and as the lead ships they came under heavy mortar and machine gun fire from North Korean defenders on Cemetery Hill . Despite the concentrated fire , they disembarked assault troops and unloaded vital support equipment . In addition their guns wiped out enemy batteries on the right flank of Red Beach . Three ( " LST 857 " , " LST 859 " and " LST 973 " ) of the eight LSTs took some hits from mortar and machine gun fire , which killed a sailor and injured a few others . The LSTs completed unloading and cleared the beach at high tide early on 16 September . After neutralizing North Korean defenses at Inchon on the night of September 15 , they opened the causeway to Wolmi - do , allowing the 3rd Battalion of the 5th Marines and the tanks from Green Beach to enter the battle at Inchon . Early morning on September 16 , the 5th Marines ( Red and Green Beaches forces ) would march through the city in Inchon , taking it by the afternoon . Red Beach forces suffered eight dead and 28 wounded . Blue Beach . Under the command of then - Colonel Lewis Burwell " Chesty " Puller , the 1st Marine Regiment landing at Blue Beach was significantly south of the other two beaches and reached shore last . The mission of Colonel Puller ' s 1st Marines in this landing was to take the beachhead , and the road to Yongdungpo and Seoul . The 2nd Battalion would land on the left at Blue Beach One and 3rd Battalion would land on Blue Beach Two . A little cove around the corner south of Blue Beach Two was called Blue Beach Three . As they approached the coast , the combined fire from several NKPA gun emplacements sank one LST . Destroyer fire and bombing runs silenced the North Korean defenses . When they finally arrived , the North Korean forces at Incheon had already surrendered , so the Blue Beach forces suffered few casualties and met little opposition . The 1st Marine Regiment spent much of its time strengthening the beachhead and preparing for the inland invasion . Air attack on USS " Rochester " . Just before daylight at 0550 on 17 September , a North Korean Yak - 9 and an II - 2 made an attack run on " Rochester " while she was anchored off Wolmi - do . Initially the aircraft were thought to be friendly until they dropped four bombs over the American ship . All but one missed and the one that did hit dented " Rochester " s crane and failed to detonate . There were no American casualties in the skirmish and they painted a Purple Heart on the crane as a reminder of how close the ship had come to being heavily damaged . After the bombing of " Rochester " , she and the nearby " Jamaica " opened fire on the attacking aircraft with their guns . The North Korean II - 2 then strafed the British cruiser , resulting in one sailor killed and two wounded . At about the same time , fire from " Jamaica " hit the II - 2 and it crashed into the water . The Yak - 9 fled after losing its partner . Aftermath . Beachhead . Immediately after North Korean resistance was extinguished in Incheon , the supply and reinforcement process began . Seabee s and Underwater Demolition Team s ( UDTs ) that had arrived with the U . S . Marines constructed a pontoon dock on Green Beach and cleared debris from the water . The dock was then used to unload the remainder of the LSTs . Documents written by Kim Il - sung and recovered by UN troops soon after the landing said , " " The original plan was to end the war in a month , we could not stamp out four American divisions . . . We were taken by surprise when United Nations troops and the American Air Force and Navy moved in . " " Early that morning of September 16 , Lieutenant Colonel Murray and Colonel Puller had their operational orders from General Oliver P . Smith . The 1st Marines and 5th Marines began moving along the Inchon - Seoul road . On September 16 , the North Koreans , realizing their blunder , sent six columns of T - 34 tanks to the beachhead . They were quite alone , without infantry support . They were spotted by a strike force of F4U Corsair at the village of Kansong - ni , east of Inchon . In response , two flights of F4U Corsair from Marine Fighter Squadron 214 ( VMF - 214 ) bombed the attackers . The armored columns suffered extensive damage and the U . S . forces lost one airplane . A quick counter - attack by M26 Pershing tanks destroyed the remainder of the North Korean armored division and cleared the way for the capture of Incheon . Capture of Kimpo airfield . The Kimpo airfield was the largest and most important in Korea . On September 17 , General MacArthur was extremely urgent in his request for early capture of Kimpo airfield for it was the largest air base in all of Korea . Once it was secured , the Fifth Air Force could bring fighters and bombers up from Japan to operate more easily against North Korea . The attack on Kimpo airfield was carried out by 2nd Battalion 5th Marines . That night at Kimpo , the North Koreans were organizing their defense of the airfield . Kimpo was under the command of Brigadier General Wan Yong . General Wan ' s troops were a conglomeration of half - trained fighting men and service forces . Several North Korean troops had already fled across the Han River toward Seoul to escape the fight . The North Korean ' s defense was almost as bad as the morale of the men who realized that they were not going to get any help from the North Korean officials in Seoul . By morning the enemy were all gone , and Kimpo airfield was securely in the hands of the Marines . Kimpo airfield was in excellent shape ; the enemy had not had time to do any major demolition . In fact , several enemy planes were still on the field . So Kimpo now could become the center of Allied land - based air operations . On September 19 , the U . S . Army Corps of Engineers repaired the local railroad up to eight miles ( 13 km ) inland . After captured of Kimpo airfield , transport planes began flying in gasoline and ordnance for the aircraft stationed there . The Marines continued unloading supplies and reinforcements . By September 22 , they had unloaded 6 , 629 vehicles and 53 , 882 troops , along with 25 , 512 short tons ( 23 , 000 tonnes ) of supplies . Battle of Seoul . In contrast to the quick victory at Incheon , the advance on Seoul was slow and bloody . The NKPA launched another T - 34 attack , which was trapped and destroyed , and a Yak bombing run in Incheon harbor , which did little damage . The NKPA attempted to stall the UN offensive to allow time to reinforce Seoul and withdraw troops from the south . Though warned that the process of taking Seoul would allow remaining NKPA forces in the south to escape , MacArthur felt that he was bound to honor promises given to the South Korean government to retake the capital as soon as possible . On the second day , vessels carrying the U . S . Army ' s 7th Infantry Division arrived in Incheon Harbor . General Almond was eager to get the division into position to block a possible enemy movement from the south of Seoul . On the morning of September 18 , the division ' s 2nd Battalion of the 32nd Infantry Regiment landed at Incheon and the remainder of the regiment went ashore later in the day . The next morning , the 2nd Battalion moved up to relieve an U . S . Marine battalion occupying positions on the right flank south of Seoul . Meanwhile , the 7th Division ' s 31st Regiment came ashore at Incheon . Responsibility for the zone south of Seoul highway passed to 7th Division at 18 : 00 on September 19 . The 7th Infantry Division then engaged in heavy fighting with North Korean soldiers on the outskirts of Seoul . Before the battle , North Korea had just one understrength division in the city , with the majority of its forces south of the capital . MacArthur personally oversaw the 1st Marine Regiment as it fought through North Korean positions on the road to Seoul . Control of Operation Chromite was then given to Major General Edward Almond , the X Corps commander . General Almond was in an enormous hurry to capture Seoul by September 25 , exactly three months of the North Korean assault across the 38th parallel . On September 22 , the Marines entered Seoul to find it fortified . Casualties mounted as the forces engaged in house - to - house fighting . On September 26 , the Hotel Bando ( which had served as the US Embassy ) was cleared by Easy Company of 2nd Battalion , 1st Marine Regiment . During this fight about 12 North Korean P . O . W . s were killed ( apparently while naked and unarmed ) in the building ' s basement . General Almond declared the city liberated on September 25 even though Marines were still engaged in house - to - house combat . Pusan Perimeter breakout . Meanwhile , 5th Marines came ashore at Inchon . The last North Korean troops in South Korea still fighting were defeated when Walton H . Walker ' s 8th Army broke out of the Pusan Perimeter , joining the Army ' s X Corps in a coordinated attack on NKPA forces . Of the 70 , 000 NKPA troops around Pusan , in the aftermath of the Pusan Perimeter battle , North Korean casualties from September 1 to September 15 could range from roughly 36 , 000 to 41 , 000 killed and captured , with an unknown total number of wounded . However , because UN forces had concentrated on taking Seoul rather than cutting off the NKPA ' s withdrawal north , the remaining 30 , 000 North Korean soldiers escaped to the north across the Yalu River , where they were soon reconstituted as a cadre for the formation of new NKPA divisions hastily re - equipped by the Soviet Union . The allied assault continued north to the Yalu River until the intervention of the People ' s Republic of China in the war in November 1950 . Analysis . Most military scholars consider the battle one of the most decisive military operations in modern warfare . However , Russell Stolfi argues that the landing itself was a strategic masterpiece but it was followed by an advance to Seoul in ground battle so slow and measured that it constituted an operational disaster , largely negating the successful landing . He contrasts the US style of war fighting with that of Germany by examining the US military ' s 1950 Incheon - Seoul operation and the German offensive in the Baltic in 1941 . American forces achieved a strategic masterpiece in the Incheon landing in September 1950 and then largely negated it by a slow , tentative , 11 - day advance on Seoul , only twenty miles away . By contrast in the Baltic region in 1941 the German forces achieved strategic surprise in the first day of their offensive and then , exhibiting a breakthrough mentality , pushed forward rapidly , seizing key positions and advancing almost two hundred miles in four days . The American advance was characterized by cautious , restrictive orders , concerns about phase lines , limited reconnaissance , and command posts well in the rear , while the Germans positioned their leaders as far forward as possible , relied on oral or short written orders , reorganized combat groups to meet immediate circumstances , and engaged in vigorous reconnaissance .