As the Eighth Army neared a natural defensive position along the Naktong River, the North Koreans accelerated their efforts to cut off elements of that army. After the fall of Seoul in late June the North Korean 6th Division had crossed the Han River and rapidly moved south over the western coastal roadnet. Eighth Army intelligence lost track of the 6th. The only UN forces situated at the time southwest of the Taejon-Taegu-Pusan highway were a few hundred ROK 7th Division survivors along with some scattered ROK marines and local police. On 21 July General Walker learned that a North Korean unit, presumed to be the 4th Division, was operating in the southwest area. Walker ordered the 24th Division, despite its deficiencies in manpower and equipment after the loss of Taejon, to serve as a blocking force in the area from Chinju in deep south central Korea northward to Kumch’on. Two battalions of the 29th Infantry, then stationed on Okinawa, and the ROK 17th Regiment would reinforce the 24th Division.
On 23 July the North Korean 4th Division moved south from Taejon with the intent of supporting the 6th Division in an envelopment of the United Nations’ left flank and driving to Pusan. The 4th pushed as far as the Anui-Koch’ang area, about fifty miles southwest of Taegu, by the end of July. During 25–28 July the two battalions of the 29th were driven back by elements of the 6th at Hadong, located about twenty-five miles west of Chinju. On 31 July the Eighth Army finally became aware of the 6th Division’s presence after the 6th took Chinju and forced one battalion of the 29th and the 19th Infantry of the 24th Division to withdraw to the east. Eighth Army rushed the 27th Infantry of the 25th Division, which had been in reserve, to reinforce American units in the Chinju-Masan corridor. The 24th and 25th Divisions, aided by the ROK 17th Regiment, finally managed to slow the progress of the North Korean 4th and 6th Divisions at what would become the southernmost sector of the Pusan Perimeter. By 3 August U.S. and ROK units had averted the immediate threat of a North Korean drive all the way to Pusan.
On 1 August the Eighth Army issued an operational directive to all UN ground forces in Korea for their planned withdrawal east of the Naktong River. UN units would then establish main defensive positions behind what was to be called the Pusan Perimeter. The intent was to draw the line on retreating and hold off the NKPA while the U.S. Army could build up its forces and wage a counteroffensive. The Pusan Perimeter assumed by U.S. and ROK forces on 4 August involved a rectangular area about 100 miles from north to south and 50 miles from east to west. The Naktong River formed the western boundary except for the southernmost 15 miles where the Naktong turned eastward after its confluence with the Nam River. The ocean formed the eastern and southern boundaries, while the northern boundary was an irregular line that ran through the mountains from above Waegwan to Yongdok. From the southwest to the northeast the UN line was held by the U.S. 25th and 24th Infantry and 1st Cavalry Divisions, and then by the ROK 1st, 6th, 8th, Capital, and 3d Divisions. From south to northeast the North Korean units positioned opposite the UN units were the 83d Motorized Regiment of the 105th Armored Division and then the 6th, 4th, 3d, 2d, 15th, 1st, 13th, 8th, 12th, and 5th Divisions and the 766th Independent Infantry Regiment. The 5th Regimental Combat Team from Hawaii and the phased arrival of the 2d Infantry Division from the United States augmented U.S. Army forces. A third major reinforcement arrived in Korea on 2 August, the 1st Provisional Marine Brigade, about 4,700 men. UN combat forces at this point actually outnumbered the North Koreans, 92,000 to 70,000.
The North Koreans had four possible avenues of advance leading to Pusan that could result in the defeat of U.S. and ROK forces, and in August they tried them all simultaneously. These approaches went through Masan south of the confluence of the Nam and Naktong Rivers, through the Naktong Bulge to the rail and road lines at Miryang, through Kyongju and down the east coast corridor, and through Taegu. During the first week of August General Walker decided to launch the first American counterattack of the war in the Chinju-Masan corridor. One of his purposes was to break up a suspected massing of enemy troops near the Taegu area by forcing the diversion of some North Korean units southward. On 6 August the Eighth Army issued the operational directive for the attack by Task Force Kean, named for the 25th Division commander. Task Force Kean consisted of the 25th Division, less the 27th Infantry and a field artillery battalion, with the 5th RCT and the 1st Provisional Marine Brigade attached. The Army plan of attack required the force to move west from positions then held near Masan, seize the Chinju Pass, and secure the line as far as the Nam River. Task Force Kean launched its strike on 7 August but ran head-on into one being delivered simultaneously by the North Korean 6th Division. After a week of heavy fighting, neither Kean’s troops nor their opponents had made any appreciable progress. Even so, the Eighth Army had launched its first offensive in Korea and successfully halted an assault by an enemy division.
Infantrymen helping a wounded comrade (National Archives)
Seven air miles north of the point where the Naktong River turns east and the Nam River enters it, the Naktong curves westward opposite Yongsan in a wide semicircular loop. This loop became known to the American troops as the Naktong Bulge during the bitter fighting there in August and September. On 6 August the North Korean 4th Division crossed the Naktong at Ohang with the intent of driving to Yongsan located about ten miles to the east. The 24th Division defended that sector and the 24th commander, Maj. Gen. John H. Church, who had succeeded General Dean as division commander, placed the defense of the Naktong Bulge under Task Force Hill. Task Force Hill consisted of the 9th Infantry of the 2d Infantry Division along with the 34th and 19th Infantries and a battalion of the 21st Infantry of the 24th Division. Despite the efforts of Task Force Hill, by 11 August the 4th Division had penetrated to the vicinity of Yongsan. General Walker then added to the fray the 23d Infantry of the 2d Division, the 27th Infantry of the 25th Division, and the 1st Provisional Marine Brigade.
General Church led the coordinated attack of Army and Marine Corps troops against the North Koreans that began on 17 August. By the eighteenth the American forces had decisively defeated the 4th Division, which had lost half its original strength of about 7,000 men.
Located about twenty miles south of P’ohang-dong on the east coast, Kyongju was an important rail and highway center situated within the Taegu–P’ohang-dong–Pusan triangle inside the Pusan Perimeter. The capture of P’ohang-dong and the nearby Yonil Airfield, used by the Far East Air Force, would open a natural and essentially undefended corridor for the NKPA to move directly south through Kyongju to Pusan. General Walker had only lightly fortified the east coast corridor because the enemy threat was more immediate on the western perimeter, and he doubted that the North Koreans could mount a major successful drive through the trackless mountains. In early August the enemy almost proved Walker wrong when three North Korean divisions—the 5th, 8th, and 12th—and the 766th Independent Infantry Regiment mounted strong attacks against the ROK defenders. By 12 August the North Koreans had pressed to P’ohang-dong and also threatened Yonil Airfield. The North Korean 5th Division cut off the ROK 3d Division above P’ohang-dong, and the 3d Division had to be evacuated by sea to positions farther south. General Walker reinforced the ROK units in the area with elements of the U.S. 2d Infantry Division. By 17 August ROK units and the 2d Division had managed to check the enemy drive at P’ohang-dong. A primary factor in stopping the North Koreans was logistics, as the enemy had outrun his supply line during the difficult trek southward through the mountains.
The natural corridor of the Naktong Valley from Sangju to Taegu presented another principal axis of attack for the NKPA. The sizable enemy forces assembled in an arc around Taegu in early August from south to north consisted of the 10th, 3d, 15th, 13th, and 1st Divisions and elements of the 105th Armored Division. Opposite the North Korean divisions were the U.S. 1st Cavalry Division and the 1st and 6th Divisions of the ROK II Corps. The North Koreans crossed the Naktong River in several places within the arc around Taegu during the second week of August. When several enemy artillery shells landed in Taegu on 18 August, President Rhee ordered movement of the Korean provincial government, then in Taegu, to Pusan. The North Korean 1st and 13th Divisions posed the primary threat as they pressed toward Taegu by overland routes from the north and northwest. General Walker moved up the 23d and 27th Infantries, both fresh from defensive action in the Naktong Bulge, to reinforce the ROK 1st Division, which confronted the North Korean 1st and 3d Divisions in its sector. Although the North Korean 1st Division pushed to within nine miles of Taegu, the combined efforts of the ROK 1st Division and the U.S. 23d and 27th Infantries frustrated enemy efforts to penetrate to Taegu.
Even though the North Korean People’s Army had seriously threatened the United States and ROK Armies within the Pusan Perimeter during August 1950, the defenders both successfully resisted the enemy attacks and continued the buildup of forces for a counteroffensive. The Far East Air Force had established air supremacy over the North Koreans early in the war and continued to influence the outcome of battles by multiple sorties in close support of ground troops, 4,635 in July and 7,397 in August. By late August there were more than 500 American medium tanks within the Pusan Perimeter. The tanks in tank battalions were equally divided between M26 Pershings and M4A3 Shermans, except for one battalion that had the newer M46 Pattons. On 1 September the United Nations Command had a strength of 180,000 in Korea: 92,000 were South Koreans and the balance were Americans and the 1,600-man British 27th Infantry Brigade. In August the North Koreans continued the plan and tactics begun at the Han River in early July with a frontal holding attack, envelopment of the flank, and infiltration to the rear. When the Eighth Army stabilized the line at the Pusan Perimeter, these tactics no longer worked and success could come only by frontal attack, penetration, and immediate exploitation. Generals MacArthur and Walker countered with classical principles of defense—interior lines of communications, superior artillery firepower, and a strong air force. By 1 September the North Koreans had assembled a 98,000-man army for a massive offensive against the Pusan Perimeter. However, they experienced substantial problems: a third of their ranks manned by forcibly conscripted and untrained South Koreans, a major shortage of small arms, and only enough rations for one or sometimes two meals a day.
Engineers probe for enemy mines ahead of a creeping tank
In early September as during August, General Walker faced dangerous situations in essentially the same places along the Pusan Perimeter: in the east at P’ohang-dong to include a potential severing of the corridor between Taegu and P’ohang-dong, north of Taegu where the enemy made disturbing gains, at the Naktong Bulge, and in the Masan area in the extreme south. Also as he had during the fighting in August, Walker continued his masterful tactics of shifting his forces from one threatened enemy penetration to another. In early September the ROK 3d, Capital, 8th, and 6th Divisions held the line farthest to the east against the North Korean 5th, 8th, 12th, and 15th Divisions. Maj. Gen. John B. Coulter, newly appointed deputy commander, Eighth Army, assumed command of American units in the eastern sector and employed the 21st Infantry of the U.S. 24th Division and other supporting units to bolster the ROK divisions. On 7 September General Church replaced Coulter as American commander in the eastern sector after General Walker ordered the entire 24th to reinforce the ROK divisions. A combination of ground fighting, predominantly by the South Koreans, along with American close air support and naval gunfire from offshore inflicted serious losses on the enemy divisions. The North Korean 1st, 3d, and 13th Divisions pressed the attack north of Taegu against the U.S. 1st Cavalry Division, which prompted Walker on 5 September to move the main Eighth Army headquarters from Taegu to Pusan. The 1st Cavalry Division essentially checked the thrusts of the North Koreans north of Taegu, but fighting continued there into mid-September.
At the end of August the North Korean People’s Army also planned a crushing blow against the U.S. 2d and 25th Divisions in the southern part of the Pusan Perimeter. The enemy’s 6th Division would attack through Haman, Masan, and capture Kumhae, fifteen miles west of Pusan. The 7th Division was to strike north of the Masan highway, wheel left to the Naktong River, and wait for the 6th Division on its right and the 9th on its left and then resume the attack toward Pusan. The 25th Division held the southernmost sector that ran from the confluence of the Naktong and Nam Rivers to the southern coast, while the 2d Division was positioned in the area across the Naktong River north of the 25th. The North Korean 9th Division faced the 2d Division at the Naktong Bulge and had the mission of capturing the towns of Miryang and Samnangjin, thereby cutting off the Eighth Army route of withdrawal between Taegu and Pusan. During the first week of September the 9th Division penetrated the Naktong Bulge as far east as Yongsan, but a counterattack by the 2d Division together with the U.S. 1st Provisional Marine Brigade pushed back the 9th almost to the Naktong River. The 2d Division’s 23d Infantry beat back the North Korean 2d Division six miles north of Yongsan at Changnyong. At the same time the 6th and 7th Divisions mounted strong attacks against the 25th Division. Despite enemy penetrations into the sectors of the 25th’s regiments—the 35th Infantry’s sector west of Ch’irwon and the 24th Infantry’s sector near Haman that was effectively stopped by the 27th Infantry—the 25th Division repelled the NKPA’s offensive in the south. The Naktong River line held, and the Pusan Perimeter was secure.