Here ridges trend mostly north-south but valleys extend in all directions. The region is rugged, partly forested, and well-drained but unfavorable for crosscountry movement. Hills and ridges are generally 1,500 to 5,000 feet high and are steep. Valleys arc narrow, gorge-like, and extremely winding. In their upper reaches the larger westward flowing rivers, such as the Chongchon, the Taedong, the Yesong, and the Imjin, flow in narrow, steep-sided valleys or gorges which provide no room for extensive movement or deployment. No routes suitable for rapid, large scale movement cross the region in any direction. Existing roads are narrow and winding and cross steep passes 2,000 to 3,600 feet high.'
The 39th Parallel may be identified closely with the waist of Korea. The parallel runs through Pyongyang on the west side of the waist and emerges into the Sea of Japan only 12 miles south of Wonsan on the east side.
The waist of Korea runs laterally from west to cast from the North Korean capital of Pyongyang on the west side of the peninsula to Wonsan, a major port on its cast side, an air-mile distance of about 100 miles. A vehicular road and a railroad connect the two places, winding through the Northern Taebaek Mountains most of the way. The vehicular road is approximately 150 miles long. This road in December 1950 was a poor one, dirt all the way, and in some places only one track wide.
If one extends the southwestern terminus of the waist of Korea corridor to the Korea Bay and includes the port of Chinnampo, 30 miles southwest of Pyongyang, then the waist of Korea would be about 125 air miles from sea to sea, from the Yellow Sea on the west to the Sea of Japan on the east. The vehicular road would be about 180 miles long. It would be logical to include the Chinnampo area within any defense line across the waist of Korea, since Chinnampo, the port for Pyongyang, would be of great logistic importance in defense warfare at the waist of Korea. There is no vehicular road or railroad crossing the peninsula north of the waist of Korea, although there are several of both crossing Korea laterally south of the waist. This fact obviously was of great importance to adversaries located on either side of the waist.
North of the waist of Korea there was a meager population living in small villages for the most part, with only the most primitive communications and transport system in a mountainous area. South of it there was an increasing density of population and a far better developed transportation and communication system. All the large cities in Korea were in, or south of, the waist of Korea except for the port of Hungnam and the nearby city of Hamhung on the east coast, north of Wonsan. These factors would strongly favor any military force occupying the waist of Korea and the land south of it. Those defending at the waist of Korea against a hostile force from the north would be in a favorable position.
The highway across the waist of Korea, starting at Wonsan on the east, passes through the principal towns and villages of Majon-ni, Tongyang, Yongdok, Songchon, and Kangdong. At Kangdong it meets the Taedong River and from there follows its course generally west to Pyongyang, twenty-odd miles away.
The lateral railroad at its eastern end does not follow the vehicular road from Wonsan but starts west across the waist from the town of Kowon, about 25 miles northwest of Wonsan, where it meets the main east-coast railroad, which continues on to Soviet Siberia. From Kowon the railroad goes nearly due west for approximately 25 air miles and then bends sharply south to Yongdok, where it meets the vehicular road from Wonsan. Thereafter, it generally follows the course of the road until it reaches Kangdong, where it crosses the road and continues south for about 15 miles and then turns directly west toward Pyongyang. Of the towns mentioned on the vehicular road, the railroad after leaving Kowon goes through only Yongdok and Kangdong, but it passes close to Songchon.
For the most effective use of the logistic values of the railroad, the waist of Korea defense line would have to include the area as far north as Kowon on the east side. The defense line would have to encompass both the railroad and the vehicular road and he located to protect them from the north. Such a line would have to be located by engineers and tactical officers after a careful reconnaissance of the area to include the best topographical features. Such a study was never made.
The drainage pattern in the vicinity of Majon-ni, including the headwaters of the Imjin River and the lower course of the Taedong River, would probably have influenced the location of such a defense line. For the rest there would have had to have been selection of commanding ground and communication intersections on the north side of the lateral rail and vehicular road which required protection. Strong defenses would have had to be established at both Wonsan and Pyongyang. Naval forces could have been used to good advantage offshore at Wonsan and to a lesser extent at the mouth of the Taedong River estuary at and below Chinnampo.'
Aside from air reconnaissance, UN forces had very little firsthand knowledge of the condition of the lateral road from Pyongyang to Wonsan. Research revealed only one party of American soldiers who passed over it from end to end. According to Lt. Gen. William J. McCaffrev, USA, Ret. (a lieutenant colonel in charge of X Corps Advance CP at Wonsan in October 1950), Lt. Col. Olinto Barsanti with a small party in three jeeps drove from Wonsan to the SukchonPyongyang area in late October 1950 to establish contact with the 187th Airborne RC E' McCaffrey, who flew in a light plane from Wonsan over the eastern part of the road, said it was deserted at the time. He saw no enemy but noticed empty foxholes on ridges along both sides of the road at some places. The road itself looked to he hardly passable at many points.
The importance of the waist of Korea lay in the short distance across the peninsula from sea to sea on both flanks and in its communications and logistic facilities to the party that held it. This value is attested in a study published by the Far Fast Command in 1953, in which it stated that "the majority of [enemy] supply installations ... are located contiguous to the major traffic arteries and the bulk of the enemy's major supply installations are encountered in the area adjacent to, and just below, the 39th parallel."'
This study stated that the road from Chongjin to Wonsan (No. 5), the coastal road from the Soviet border along the cast coast to Wonsan, carried a surprisingly large amount of traffic and was maintained by a tremendous amount of repair work in the face of concerted UN efforts to disrupt its traffic. This road connected at Wonsan with the lateral route across the waist of Korea (No. 6). It said that, other than routes of entry into Korea from the Soviet Union and Manchuria, this lateral road was among the most important to the enemy in all Korea. The study stated further:
Among the most important [roads] is undoubtedly Route No. 6 (Pyongyang to Wonsan) which runs generally along the 39th Parallel and through the major enemy supply complexes in NK. This route is the only major East-West route available to the enemy in Korea and consequently considerable stress has been placed on its maintenance and repair. This route is a one and a half to two lanes gravel surfaced road with paved stretches as wide as thirty feet in urban areas, but has steep grades, sharp curves, and frequent defiles, particularly in the mountain areas. Due to constant enemy maintenance efforts along this route, it appears capable today of sustaining more traffic in relation to its originally assessed peace-time capacity than any other road in NK.s
The rail line from Kowon on the east coast to Pyongyang and to Sinanju via Sinchang-ni and Sunchon is listed as being 143 miles to Sinanju. About twothirds of the way across the waist, a branch of the main rail line slants northwest to Sinanju via Kunu-ri, to make connection with the main west-coast rail line from Antung in Manchuria. Thus, there was rail connection from both main coastal rail lines into the heart of the waist of Korea. The Far East Command study, previously cited, stated that the enemy had made "special effort to keep this cast-west link of the rail line open and operable. The main supply complexes of the enemy armies in N Korea are located contiguous to this line."
These observations, made two years after Barsanti and McCaffrey noted the primitivc nature of the roads at the end of 1950, show how important the communications across the waist of Korea became
to the Chinese and North Koreans following the UN retreat south of this strategic area in Korea in December 1950. They would have been equally important to the UN forces had they held this area, which they might well have done.
Some of the better informed and more perceptive war correspondents in Korea were aware that for the UN army to go north of the waist of Korea was a risky and dangerous adventure. One of them, Homer Bigart of the New York Herald Tribune, in a dispatch from the Chongchon River front on 28 November charged that the UN was beginning to pay the "initial price for the unsound decision to launch an offensive north of the peninsula's narrow neck." At that time he thought there were enough troops in Korea, if the X Corps in northeast Korea could he united to Eighth Army quickly, to hold "the neck of Korea." A week later he dispatched another report to the Herald Tribune from Seoul in which he alluded to the decision of the UN command to go beyond the waist of Korea. Events had proceeded faster and with more devastating results than even he had conceived possible just a week earlier. Now he wrote:
Already some thoughtful officers are beginning to question the sanity of recent military decisions which may not have caused, but which certainly accelerated, this crisis. The most questionable decision of the last few weeks was MacArthur's abortive offensive. Before the offensive was launched, it was noted by some observers that any attempt to push beyond the neck of the peninsula would be unsound-even if the Communists withdrew. To fan out on a 700 mile frontier made no sense. It was an invitation to disaster.
Adequate vigilance of the frontier would have required a force many times that of the UN ... certainty of border incidents would compel UN troops to remain in Korea indefinitely.'
In Washington, there had been for a long time much worry over General MacArthur's tendency to ignore, or to talk his way around, instructions from the Joint Chiefs of Staff about how far north he should go in Korea. It was the settled opinion of the Joint Chiefs, the secretary of state, and the president, as well as the British prime minister, that the UN forces, except possibly the ROK troops, should not go beyond the waist of Korea and that they should stop there and establish a well-fortified defense line. The trouble was that the Joint Chiefs did not make MacArthur toe the line laid down. He was always able to protest their decisions and in the end obtain a modification or some vagueness that allowed him to scramble through to suit his own ends. On 29 September in Washington, President Truman, Secretary of State Acheson, and Secretary of Defense Marshall, with military situation maps of Korea in front of them, unanimously decided that MacArthur should "occupy, fortify and hold the line Pyongyang-Wonsan"- the waist of Korea. North of that line they thought South Korean troops might operate.'
Directives were sent to MacArthur on 30 September that reflected this viewpoint. On 25 October the Joint Chiefs of Staff protested MacArthur's attack order of the day before as a violation of his orders of 30 September.' Acheson says that "the Joint Chiefs and Marshall fumed, saw the danger involved, but ... were not willing to order MacArthur back to the September 30 line."
On 30 November 1950, General MacArthur sent a message to the Pentagon saying that the idea of joining the Eighth Army and the X Corps across the narrow neck of Korea was quite impracticable because of logistic problems posed by the mountainous divide. The Joint Chiefs responded the same day, saying, "regarding the mission assigned you by the UN the entire region northeast of the waist of Korea should be ignored except for strategic and tactical considerations relating to the security of your command."9
When the evacuation of Pyongyang was imminent, the Joint Chiefs on 1 December asked MacArthur again if he could establish and hold a defensive line across the waist of Korea. He replied on the third that it was not practicable to do this. The irony of his reply is that it was true-most of Eighth Army was already south of the waist of Korea and could not possibly be used in an effort to hold it.10
It really made no difference now what the Joint Chiefs thought. It was too late to make any effort to hold the waist of Korea. It had been given to the enemy. Any commonsense appraisal of the dialogue between the Joint Chiefs of Staff and MacArthur on the conduct of the war in Korea has to end with the conclusion that the Joint Chiefs did not exercise their superior command function over General MacArthur to hold him to a course they thought best served the US national interest. They, too, failed in their duty.
North Korean Guerrilla Action behind Eighth Army
In October, after the Inchon landing and the capture of Seoul, when Eighth Army hurriedly drove north toward Pyongyang and subsequently on toward the Yalu border, it ignored the many fragments of North Korean Army units left behind, many of them in mountains along the Seoul-Wonsan corridor between the South and North Taebaek ranges. These defeated and disorganized groups of regular North Korean Army soldiers varied in size from squads and platoons to nearly regiments. Some of them continued north to a general rendezvous in the Kanggye area in the central mountains near the Yalu. There they reorganized, filled their ranks with conscripted Koreans, and reequipped and trained for recommitment to battle. Other depleted units crossed into Manchuria, where they reequipped, retrained, and reorganized. But large numbers of the defeated North Korean Army remained in mountainous parts of central North Korea, where they took up guerrilla operations against supply and transport routes and service units in the Eighth Army rear areas. These guerrilla operations southeast of the waist of Korea took their toll and spread increasing uneasiness in the UN command.
In the Eighth Army sector, the North Korean harassing operations in the army rear north of the 38th Parallel centered in a key strategic area that became known as the Iron Triangle, with corners at Pyongyang (not to be confused with Pyongyang) on the north, Kumhwa at the southeast, and Chorwon at the southwest. Chorwon lay only 45 air miles north of Seoul.
This hotbed of enemy guerrilla action lay 80 to 100 air miles southeast of Pyongyang, deep in the Eighth Army rear. There was always the threat that this enemy force, if it increased in size and organized under a unified command, could cut the MSR north from Seoul to the Eighth Army front. From ancient times, Chorwon had been on the main invasion route to Seoul, and indeed it had been the main route to Seoul in the North Korean invasion of South Korea only six months earlier.
It was noticeable that North Korean guerrilla operations in the Iron Triangle area increased markedly in late October and throughout November, reaching a new high when the CCF launched their 2nd Phase Offensive in the last week of November. The question arose, Was there coordination between the two?
As early as 9 November a force of North Koreans attacked Chorwon in the Iron Triangle, and scattered guerrilla actions there continued throughout the month. The Eighth Army command was particularly disturbed by increasing enemy action that far behind its front lines. The level of activity of these bypassed North Korean elements in that part of the army's rear reached such proportions that the ROK 2nd and 5th divisions, far understrength and untested, were assigned the task of driving guerrillas from the area and then of holding it. On 22 November, a force of approximately 1,500 North Koreans attacked the ROK 17th Regiment, 2nd Division, at Chorwon from east and southwest of the town. At the same time, the 31st and 32nd regiments of the ROK 2nd Division came under North Korean attack in the Kapyong area, about 35 air miles southeast of Chorwon and only ten miles west of Chunchon.
The next day, 23 November, a strong North Korean force ambushed the ROK 3rd Battalion, 17th Regiment, between Yonchon and Chorwon, in which the ROK battalion lost three truckloads of ammunition. That day the 1st Battalion withdrew from Chorwon. Fighting continued in the Kapyong area. The following day an airdrop near Chorwon resupplied the 1st and 3rd battalions, ROK 17th Regiment, and they then moved across country to join the rest of the regiment six miles south of Chorwon. Chorwon remained in North Korean possession. Eighth Army officials considered the situation critical at Chorwon." In the meantime, the 1st Battalion, 31st Infantry, ROK 2nd Division, attacked from Hongchon toward Chunchon to clear that area of g
uerrilla forces. An enemy force estimated to number 2,000 met it four miles southeast of Chunchon, repulsed it, and forced its withdrawal ten miles southeast.
The night of 24-25 November, the night before the CCF 2nd Phase Offensive struck Eighth Army, North Korean army units hit in the ROK II Corps rear with especially devastating effects. A North Korean force descended on Yonchon, where the ROK II Corps had a rear-area supply point. The 60 South Korean police guarding a bridge five miles south of Yonchon were either killed or captured, and the bridge destroyed. ROK army supplies at Yonchon were either captured and taken away or destroyed. In the Kapyong area, ROK 5th Division forces failed to dislodge North Korean troops.'2
Finally, at 6 A.M. on 26 November the ROK 2nd and 5th divisions undertook a coordinated counterattack to sweep the North Korean guerrillas from the Iron Triangle and adjacent areas centering on Chunchon, Hwachon, and Yonchon. Intelligence estimated at the time that there were two enemy regiments totaling about 7,000 soldiers at Chorwon and about 3,500 in the KapyongChunchon areas. Chorwon was considered the strongest enemy point, with the reconstituted NK II Corps Headquarters there. At Chorwon, the North Koreans were astride the railroad running south from Wonsan."
On 29 November, the Eighth Army G-3 staff indicated it had received reports that CCF troops on its right flank had linked up with guerrilla forces, elements of the NK 10th and 7th divisions, which had been fighting the ROK 2nd and 5th divisions in the Iron Triangle area and near Chunchon. Eighth Army intelligence reported that guerrilla activity in these areas was being coordinated from a higher enemy headquarters, with the intent to disrupt conditions in the American rear areas until CCF troops could arrive."
Disaster in Korea Page 55