American M-26 tanks roll in as the UN forces retake
the South Korean capital in the Second Battle of Seoul.
The Assault
September 25 was the first day of fighting in Seoul itself,
mostly by the 1st Marines. On this first day in Seoul, however, Puller’s men
had to fight without their armor support. The crossing site used by the 1st
Marines on the previous day lacked the heavy pontoon barges needed to move the
tanks, so the tanks had to drive further north, to the location where the 5th
Marines had first crossed. Those tanks made it across the Han on the morning of
the twenty-fifth, but poor terrain, enemy contact, and mines all combined to
keep them out of the city for the day. Even without that support, elements of
the 1st Marines pushed 2000–2700 yards into the city, against heavy enemy
resistance, before setting up their night-time defensive positions.
Delays in the 5th Marines’ efforts to clear the northwest
hill mass prompted Almond to order the 32nd Infantry Regiment and 17th ROK
Regiment (paired with the 32nd) to attack into the city from the south. On the
morning of the twenty-fifth, the 32nd Infantry did just that, crossing the Han
in amphibious tractors, advancing toward their objective of South Mountain, or
Namsan to the Koreans. After driving 3500 yards north, aided by fog and
surprise, they captured their objective by 1900, a 260-meter hill overlooking
the city. While South Mountain itself was not urban terrain, it was important
for the visibility it gave of the entire city. The 32nd Infantry was quickly
followed across the Han by the 17th ROK Regiment, which then turned right to
capture a series of hills to the east.
The 5th Marines spent the twenty-fifth with split duty, with
some of its troops clearing the rest of the hills at the edge of the city, and
others pressing into Seoul. The 7th Marines were north of the city, where they
remained throughout the battle. X Corps had assigned them a series of
high-ground objectives lying just north of the city.
The North Korean reaction to these initial penetrations into
Seoul was twofold. First, they started moving forces out of the city to the
northeast, apparently thinking this was an option soon to be precluded by the
American advance north and south of Seoul. Second, they launched several strong
counterattacks against US units in or at the edge of the built-up area.
Unfortunately for X Corps, Almond recognized only the first reaction.
Earlier, on 25 September, US aerial reconnaissance had
reported a large number of enemy leaving the city to the northeast. This led
Almond to conclude the North Koreans were in full retreat, and he then ordered
the 1st Marine Division, late that night, to conduct an immediate attack. The
1st Marine Division commander, Maj. Gen. Oliver P. Smith, objected strenuously,
but he was overruled by the X Corps chief of staff, and Smith set 0200 (26
September) for both the 1st and 5th Marines to attack.
Just minutes before the attack was to commence, a forward
reconnaissance patrol for the 1st Marines reported that a major enemy
counterattack was about to begin in their sector. Puller reacted by calling in
all the artillery support he could get, and his men spent the rest of the night
in what was arguably the largest urban fire fight in US military history. The
Marines estimated the attacking force as at least a full battalion of infantry,
supported by heavy mortars and fourteen tanks and self-propelled guns. Puller’s
men held, supported by seven tanks, decimating the attackers. It was an
indication that the fight for Seoul would be more like that for Yongdungpo than
Inchon. Also hit that night were the 5th Marines and the 32nd Infantry Regiment.
The attack on the 5th Marines was smaller, but approximately one thousand NKPA
troops struck the 32nd Infantry in their positions. One company of the 32nd was
overrun before US reserves threw the attackers back by morning.
X Corps had assigned the majority of Seoul to the 1st Marine
Division. The 1st Marine Division tasked the 5th Marines with a smaller zone,
in the northwest of the city, probably in recognition of the heavy losses they
had suffered clearing the hills outside the city. The 1st Marines were assigned
the largest sector, a wide strip through the center of the city, starting from
the southwest corner and continuing to the northeast edge. X Corps assigned the
remainder of the city to the 32nd Infantry Regiment and the 17th ROK Regiment.
X Corps attached several battalions of Korean marines to various US units to
aid with mopping up and flank protection.
On the morning of 26 September the assault recommenced, and
US forces soon learned the rest of the NKPA defensive plan. At most
intersections, North Korean forces had set up barricades made mostly of rice
bags filled with dirt. These barricades were covered by infantry in nearby
buildings, mines in front of the barricades, and often artillery and/or tanks.
US troops quickly developed a process for breaking through each barricade, but
it was time consuming. The 1st Marines were able to advance 1000–1500 yards to
the northeast against heavy resistance that day, while the 5th Marines made
“limited gains” against similar resistance in their sector. The 32nd Infantry
Regiment, along with the 17th ROK, continued to push eastward, taking more of
the high ground between the city and the Han, and inflicting heavy losses on
enemy columns moving east of the city.
On 27 September the 32nd Infantry Regiment pushed north and
west of South Mountain, to clear parts of the city not in the zone of the 1st
Marines, making contact with the Marines before noon. The 5th Marines pressed
on in their sector, initially against heavy resistance, but by late afternoon
they were mopping up. The 1st Marines continued to advance against a “most
skillful delaying action,” while South Korean marines mopped up behind them.
By the afternoon of 28 September, organized resistance in
the city was broken, with the remaining NKPA forces having retreated out of the
city to high ground to the north and east. The 17th ROK Regiment and the 7th
Marines had both advanced eastward, although at no time during the battle was
the city cut off. “By late afternoon, both Division Commanders reported Seoul
had been cleaned up except for very minor sniper fire.” Mines were still a
significant impediment to movement through the last remaining portions of the
city, but the battle was over.
Command, Control, and Communications
Several operational factors made command and control in
Seoul difficult. The first was the short time available for planning. The plan
for the Inchon-Seoul operation, Operation Plan 100B, was not published until 12
August, and the X Corps headquarters was not operational until 31 August. The
short planning cycle led to many ad hoc command arrangements and
disorganization in units and personnel. The planning rush kept the focus on the
big picture, and left many details to be worked out later. A dearth of
intelligence on crossing sites for the Han was a key factor.
Since exact river crossing sites could not be predetermined,
detailed plans for the seizure of Seoul could not be prepared by division until
the lower downstream crossing of the Han had been secured.
After the 5th Marines had crossed the Han, Almond met with
the 1st Marine Division and 7th Infantry Division commanders, to plan the
assault on Seoul. Smith wanted a frontal assault from the northwest to punch
through the increasing resistance facing his 5th Marines, with all three of his
infantry regiments, while Almond favored attacking the city from several directions.
Almond gave Smith his frontal assault, although with a deadline of 24 September
to enter Seoul. When that did not happen, Almond ordered the 32nd Infantry
Regiment and the 17th ROK Regiment to cross the Han northward into Seoul on the
twenty-fifth.
The other crucial operational factor was Almond himself.
Having spent the preceding eighteen months before the landings as MacArthur’s
chief of staff, Almond shared some of MacArthur’s over optimism and taste for
publicity. When the 5th Marines crossed the Han on 20 September, MacArthur told
the commander of the 5th Marines that the NKPA forces would “evaporate very
shortly.” On several occasions Almond told Smith that he wanted Seoul captured
by the twenty-fifth, so he could issue an announcement on the three-month
anniversary of the North Korean attack. When the rate of advance was
substantially behind this timeline, Almond declared the city captured anyway,
just before midnight on 25 September. Almond was strongly influenced by
intelligence reports from X Corps reconnaissance aircraft that large numbers of
NKPA troops were leaving the city, just prior to dusk on 25 September.
Based on that information, at 2040 on 25 September, Almond
ordered the 1st Marine Division to attack into Seoul immediately. “You will
push attack now to the limit of your objective in order to insure maximum
destruction of enemy forces.” Smith was aghast, and he called back to X Corps
to explain,
The inadvisability of attacking at night in an unfamiliar
oriental city the size and complexity of Seoul, and in which there was no
indication of the enemy fleeing the Division front.
The X Corps chief of staff told him the order stood. The two
large counterattacks that hit just minutes before the Marines were to launch
their own attack demonstrated the considerable gap between conditions in Seoul
and Almond’s perception. Almond’s diary makes no mention of this episode, with no
entries from 1700 on the twenty-fifth until 0900 the next morning. Smith’s
reaction may have been a reflection of USMC doctrine at the time. A 1949 USMC
manual on urban combat states,
The larger the town and the longer it has been occupied
by the enemy, the more thorough must be the preparations for the attack.
The critical difference between Almond and Smith was that
the 1st Marine Division commander saw Seoul as a fundamentally more difficult
objective. Mirroring his superior’s error at Manila, Almond did not think the
enemy could or would fight seriously for the city. Chesty Puller’s vision for
Seoul was more accurate, when he predicted to a news correspondent that the
North Koreans would defend Seoul in a manner that would require the Marines to
destroy it. Fleet Marine Force Pacific commander Lt. Gen. Lemuel C. Shepherd
Jr. shared Puller’s outlook, telling MacArthur shortly after the 5th Marines
crossed the Han, that the NKPA would fight to the last in Seoul.
Two other significant command errors occurred. Failure to
foresee the NKPA main line of resistance resulted in the primary American
thrust into the city being delayed for several critical days, during which
substantial NKPA forces continued their escape northward. The 5th Marines’
drive into the city, from the northwest, ran headlong into the primary NKPA
defensive position. From a topographical standpoint, the hill mass northwest of
Seoul should have been viewed as a likely major defensive position, even more
so given its history as a training ground for both Japanese and South Korean
troops. A 1st Marine Division photo interpretation report, dated the day before
the 5th Marines crossed the Han (19 September), referenced the “entire area”
north of the Han and Kimpo as having been used by the Japanese and Koreans for
training, and also mentioned numerous empty defensive positions. Had this hill mass
been bypassed to the north, it is difficult to imagine the NKPA defense being
as effective as it was. The NKPA forces in those hills might have moved out and
counterattacked the 5th Marines, but the Marines proved themselves most capable
at handling such counterattacks throughout the Inchon-Seoul campaign. Almond
and Smith share the blame for this error, Almond for being fixated on a
particular date of liberation, and Smith for insisting on the most direct, but
also the most predictable, route into Seoul from the 5th Marines’ crossing
point on the Han.
The other error was the low priority Almond gave to
isolating the city. Almond put too much emphasis on capturing the city itself,
rather than denying its utility as a transit point to retreating NKPA forces.
He focused on the tactical while losing sight of the operational. Almond
assigned the task of cutting off the city to the later-arriving 7th Marines and
32nd Infantry Regiment. This resulted in an escape route out of the city to the
northeast remaining open during the battle, when resistance slowed the advance
of the first two Marine regiments. Given the resources available to Almond,
cutting off the city would not have been an easy task, but the low priority he
gave that effort increased the likelihood his forces would fail to trap any
NKPA in the city.
The two key regimental commanders, Murray of the 5th Marines
and Puller of the 1st Marines, were both highly experienced and decorated. In
eighteen months of combat operations in the Pacific in World War II Murray had
won two Silver Stars and a Navy Cross. Puller, already a legend in the Marine
Corps, had won four Navy Crosses by this point in his career. Prior to Seoul,
they had never met, although once it became clear the two regiments would be clearing
Seoul side-by-side, Murray flew over to Puller’s command post in a helicopter.
Helicopters were sometimes used by high ranking officers (e.g., Almond) to
visit units forward, but this does not appear to have been the case for units
inside the city.
Once inside the city the styles of Murray and Puller differed.
Murray used as little artillery as possible, doing minimal artillery
preparation and relying on his forward commanders and artillery observers to
call in artillery on identified enemy positions. After the battle he was
particularly proud, and the South Koreans thankful, that the Korean president’s
house (the Blue House) in his sector was not destroyed. While Puller had
sometimes been criticized during World War II for not using enough supporting
arms, in Seoul he used artillery heavily.
Establishing and maintaining contact between units in the
city proved difficult at times for US forces. On the night of the heavy
counterattacks (25 to 26 September), the 5th Marines were unable to make contact
with the 1st Marines to their south, and the 7th Marines just north of the city
could not make contact with the 5th Marines to their south. Over the course of
26 September, the 1st Marines made contact with the 5th Marines on their left
and the 32nd Infantry Regiment on South Mountain on their right. The likely
cause was the shorter lines of sight in the urban terrain, as compared to the
usual open Korean countryside. As the Marines moved into the city, the
requirement for troops per unit of distance to maintain visual contact would
have changed considerably. Apparently they adapted, although with some modest
delay.
The control and integration of Marine aircraft into the
combined arms team was outstanding. On-station Marine aircraft could deliver close
air support as quickly as artillery, and were “always immediately available”
during the day. X Corps attached Marine air controllers to Army units, and this
offered such a radically improved level of support over what the Army units
were used to from the Air Force that the Marines had to “conduct a running
seminar on how to use air support.” In January 1951, the then-commander of the
7th Infantry Division wrote a letter to the commandant of the Marine Corps
praising the quality of the close air support given his division by the 1st
Marine Air Wing over the previous four months. He cited over one thousand
sorties without a single friendly casualty. Marine units were also pleased with
the “excellent” quality of their air support, with some targets engaged within
one hundred yards of friendly units.
There were no significant command and control problems
across service and national boundaries in Seoul. During the heavy NKPA
counterattack early on 26 September against the 1st Marines, fire support duties
were skillfully handed off from Marine artillery to Army artillery, by lower
ranking officers, even though the Army artillery had been previously tasked by
X Corps to support another unit. An Army staff sergeant from an Army tank unit
attached to a Marine regiment found working with Marine infantry effective.
Several battalions of Korean marines were attached to the 5th and 1st Marines,
along with some Korean National Police, and they worked well clearing out
bypassed pockets of NKPA and stragglers disguised as civilians. Almond attached
the 17th ROK Regiment to the 32nd Infantry Regiment, and those two units worked
well in clearing out the high ground to the city’s southeast. Almond had given
extra attention in the planning of CHROMITE to coordination between the 1st
Marine Division and the 7th Infantry Division.
Almond’s rules of engagement for artillery and aircraft were
liberal. Unit reports and personal recollections from the battle make few
references to restrictions on the use of firepower. The restrictions that are
mentioned relate to unit boundaries, suspected prisoner of war holding
facilities, and certain historic structures. The mindset was apparent on 20
September, when the 1st Marines reported, in a rather business-like fashion,
they were “leveling the southern part of Yongdungpo.” The controls in place
were apparently sufficient in terms of limiting losses due to friendly fire as
only a few instances occurred.
While there were significant communications problems inside
Seoul, they were less so than during the rapid movement phase toward the city.
The pace of advance from Inchon was too fast for US communications specialists
to lay wire, which then placed a heavy burden on radio equipment. The Marines
found their radios too heavy, insufficient in range, disrupted by hilly
terrain, fragile, and powered by weak batteries. One exception was the SCR-300
backpack radio, which the 1st Marines called “the best, and most valuable,
piece of equipment rated by the infantry regiment.” Once inside the city both
the 1st and 5th Marines reported better communications, probably because the
slower pace of advance allowed wire-laying activities to catch up.
Communications with aircraft were functional but still in need of improvement, both
for aircraft and ground units. The age of Marine radios was an issue, many
having been in storage since World War II. The Marines did encounter two
urban-specific communications problems: signal blockage from steel-reinforced
buildings, and frequencies that were close enough to commercial radio frequencies
that interference resulted. In one case, a company from the 1st Marines spent a
night isolated in the heart of Yongdungpo out of radio contact. The company had
found a gap in the NKPA line and its battalion headquarters ordered it to press
forward. By sunset, when the company had set up on a key hill inside
Yongdungpo, its radio’s batteries had run out, and it is unclear how much was
known about this company’s situation by other units. The regimental commander,
Puller, stated in an interview years later, that he was unaware of the
company’s location until the next day.
That same company’s night alone provides insight into the
quality of American small unit leaders. Its commander, Captain Robert H.
Barrow, recognized the value of the terrain his company occupied, and he held
that hill all night, despite being out of contact, under repeated heavy attack,
and low on ammunition. Barrow was not the only example of high quality small
unit leadership in the difficult urban environment. While only minutes from
executing orders to attack into Seoul itself, more of Puller’s small unit
leaders were able to quickly shift into a defensive posture and hold back the
powerful NKPA night-time attack of 25–26 September. Marine small unit
commanders also proved adept at orchestrating combined arms, with the support
and weapons pushed out to smaller units, particularly as was needed for
dismantling the NKPA barricades. This level of performance was particularly
notable as Puller’s regiment conducted the bulk of the clearing operations
inside Seoul. Unlike Murray’s 5th Marines, which had experience inside the
Pusan Perimeter, the 1st Marines had been hastily assembled in the United
States just prior to the Inchon landings. They had less time to come together
as a regiment, placing greater demands on those small unit leaders. The Marine
Corps urban manual emphasized this when it stated urban combat “Will resolve
itself into small independent actions; and will place a premium upon initiative
and aggressiveness of the small unit commander.”
In sum, there were considerable problems with higher level
command and control, particularly the decisions made on how to enter and
isolate the city. And yet, once fighting in the urban landscape, command and
control at the regimental level and below was effective in clearing the city.
Intelligence and Reconnaissance
US intelligence reports prior to the landings included
detailed maps of the city down to the individual building level, but the
estimates of NKPA troop strength (5000) were almost half of the actual strength
(8000–10,000).114 The reports did describe accurately the rear area quality of
most of the units, the presence of anti-aircraft and engineer units, and the limited
ability of the NKPA to reinforce the Seoul area. Interestingly, American
intelligence personnel gave significant attention in their pre-landing
intelligence estimates to the possibility of Chinese intervention in the battle
for Seoul, as distinct from an approach to the Yalu. “Although the
international implications of such a move are considerable, the possibility
cannot be overlooked.”
American tracking of the locations and strength of NKPA
units during the battle proved challenging, with the arrival of many units into
the area, the NKPA’s re-designation of some units, and the NKPA’s creation of
some entirely new units. Many of the captured North Koreans could not describe
to their American captors how their unit fit into the overall NKPA order of
battle. Despite these difficulties, US intelligence reports during the battle
presented a fairly accurate picture of the aggregate NKPA units involved. “No
groups of enemy were met that were not previously known and their general
positions established.” It appears that US estimates on the evolving strength
of NKPA forces in the general area of the city were fairly accurate as well. A
X Corps intelligence report of 21 September, which estimated 15,000 NKPA in the
Seoul area, roughly matched the “more than 20,000” peak NKPA strength given in
the 1st Marine Division’s after-action report, the difference from NKPA
reinforcements arriving after the twenty-first.
Far less accurate were the intelligence estimates on how
well those enemy forces would fight. It was true that many of the North Korean
units in the Seoul area largely consisted of recently drafted students and
farmers, but NKPA efforts to fortify them with experienced officers proved
successful. Even after the battle, the X Corps war diary summary did not give
these units proper credit, stating these “Hastily mobilized recruits did little
to increase the enemy potential in the objective area.” Another X Corps G-2
section report, issued during the battle on 24 September, disagrees with this assessment
by describing the resistance of these units with raw recruits as “determined.”
Perhaps the X Corps war diary was reflecting the views of its commander, who
underestimated the NKPA before the battle. That sort of misjudgment occurred
again a few months later, as United Nations forces approached the Yalu,
although with far more serious consequences.
The hasty planning cycle for the Inchon-Seoul operation put
considerable strain on the intelligence organizations responsible for providing
maps and other information on Seoul. While the X Corps planning staff did have
6400 highly detailed 1:12,500-scale maps of the city for distribution, not all
of their maps used the same grid system, and there was no time to reprint them
with the standard Universal Transverse Mercator grid. Some American engineers made
their own up-to-date maps of the Inchon urban area at a 1:5,000 scale, using
recent aerial reconnaissance photos. The Far East Command Intelligence Section
produced a detailed terrain handbook for Seoul in mid-August, with information
on the city’s road network, infrastructure, and structural patterns. Given the
rapid pace of advance from Inchon to Seoul, intelligence units had difficulty
delivering the relevant maps to some units, and there were reported shortages
for pilots and at the regimental level. There were a few instances of units
being misled by errors on maps outside the city, and one tank company became
temporarily lost in the city, but such events were rare. The overall availability
of maps and information on Seoul appears to have been sufficient for the needs
of American forces in the city.
The belated recognition of the northwest hill mass as the
NKPA main line of resistance was not solely a shortfall in intelligence or reconnaissance,
but one shared with generals Almond and Smith. As early as 19 September, before
the 5th Marines crossed the Han, a 1st Marine Division intelligence report
mentioned the area as a Japanese and Korean training ground. On 21 September,
as the 5th Marines approached the hill mass, a 1st Marine Division intelligence
report characterized NKPA positions there as “apparently thin and hastily
organized” and called the stronger defense of Yongdungpo evidence of it being
the most critical front to the NKPA. However a photo interpretation section to
that same intelligence report mentioned a “system” of trenches fortifying the
hill mass. Just one day later, on 22 September, an X Corps intelligence report
would call the defenses there “well-organized,” and held by at least two
reinforced regiments with the intention of holding their positions. Two days
later, on 24 September, the 1st Marine Division called the hill mass the
enemy’s main line of resistance. Smith and Almond, given the location of the
hill mass and its previous use for training, should have deduced an alternative
to a frontal assault in case the need presented itself. US intelligence
personnel did not predict the “just in time” arrival of the NKPA forces to the
hill mass, although such a reaction was sufficiently obvious that both Almond and
Smith should have accounted for it in their plans.
Almond also erred when he concluded prematurely, late on 25
September, that the NKPA was fleeing the city. Just before dusk on 25
September, US aircraft reported columns of NKPA streaming northward out of the
city, and Almond’s G-2 section stated in its report for that day, “Remnants of
the defeated enemy appeared to be withdrawing to the north and east of the
city.” Previously, on 24 September, the 1st Marine Division issued a report
stating that, according to an informant, the NKPA was pulling out its regular
forces and replacing them with “student volunteers.” The next day another 1st
Marine Division report cited civilian accounts of NKPA movement out of the
city, and prisoner of war reports that few NKPA remained in Seoul. However,
missing were any corresponding reports from the Marine regiments in the city of
a similar retreat. Any underestimation of the NKPA’s ability to mount effective
delaying actions should have been purged from Almond’s mind after the 5th
Marine’s four-day fight for the northwest hill mass. The next day, 26
September, the X Corps G-2 section reports changed their tone to use words such
as “determined” and “stubborn” in reference to the NKPA units still in the
city.
Air reconnaissance was an important element in the US
collection apparatus. US intelligence units did not complete the first “photo
mosaic” of the Inchon to Seoul area, in 1:25,000 scale, until two days after
the Inchon landings. The tasking of photo reconnaissance missions fell behind
the initial advance of the forces moving out from Inchon, but Seoul’s status as
the main objective meant it was the target of many sorties. Photo analysts
reported approximately 250 targets in the city to the Fire Support Coordination
Center. The principal shortfall in photo reconnaissance was the time required
from request to delivery, a minimum of seventy-two hours. In addition to photo
reconnaissance, 720 visual reconnaissance flights were flown in the
Inchon-Seoul operation. However, the light aircraft primarily used for this
mission were in short supply, vulnerable to ground fire, and needed for liaison
duties. The vulnerability of the light aircraft was exacerbated by the need to
fly low (often under 2500 feet) so that well-camouflaged NKPA targets could be
acquired. Making the task for US aerial observers easier were the obvious
general locations of NKPA positions, as given away by the street barricades.
Other significant sources of intelligence on the NKPA were
North Korean prisoners and civilians. Captured NKPA soldiers were a major
source, with both X Corps and 1st Marine Division intelligence reports heavily
seeded with references to information generated from interrogations. Civilians,
sometimes walking for miles, passed on the locations of enemy forces, weapons
and ammunition caches, and NKPA movements. While generally accurate, their
reports did tend to exaggerate enemy numbers. Captured documents were sometimes
a source of information, but it was apparent to US intelligence personnel that
the NKPA had been careful to leave little documentation behind as they
retreated.
Without the help of R.O.K Officers on battalion level
tactically information from prisoners, natives and documents would have been
non-existent.
One important shortfall was noted in the 1st Marine
Division’s after-action report: “The art of reconnaissance patrolling was a
largely lost art.” While the first 5th Marine patrol sent across the Han failed
to discover the NKPA on the far bank, a patrol from the 1st Marines did give
critical warning of the impending attack in Seoul on the night of 25 to 26
September.
The skill with which the North Koreans employed camouflage
made reconnaissance and surveillance more difficult for US forces. US military
police set up checkpoints to screen out North Korean soldiers in civilian
clothes moving with the refugees, while attached ROK police proved invaluable
at these checkpoints as they could spot hiding North Koreans and “Without doubt
saved the lives of considerable American soldiers.”
