Maurice Matloff, ed., American Military History. Washington: U.S. Army and U.S. Government Printing Office, 1973.
CHAPTER 25
After the USSR installed a Communist government in North Korea in September 1948, that government promoted and supported an insurgency in South Korea in an attempt to bring down the recognized government and gain jurisdiction over the entire Korean peninsula. Not quite two years later, after the insurgency showed signs of failing, the northern government undertook a direct attack, sending the North Korea People's Army south across the 38th parallel before daylight on Sunday, June 25, 1950. The invasion, in a narrow sense, marked the beginning of a civil war between peoples of a divided country. In a larger sense, the cold war between the Great Power blocs had erupted in open hostilities.
The western bloc, especially the United States, was surprised by the North Korean decision. Although intelligence information of a possible June invasion had reached Washington, the reporting agencies judged an early summer attack unlikely. The North Koreans, they estimated, had not yet exhausted the possibilities of the insurgency and would continue that strategy only.
The North Koreans, however, seem to have taken encouragement from the U.S. policy which left Korea outside the U.S. "defense line" in Asia and from relatively public discussions of the economies placed on U.S. armed forces. They evidently accepted these as reasons to discount American counteraction, or their sponsor, the USSR, may have made that calculation for them. The Soviets also appear to have been certain the United Nations would not intervene, for in protest against Nationalist China's membership in the U.N. Security Council and against the U.N.'s refusal to seat Communist China, the USSR member had boycotted council meetings since January 1950 and did not return in June to veto any council move against North Korea.
Moreover, Kim Il Sung, the North Korean Premier, could be confident that his army, a modest force of 135,000, was superior to that of South Korea. Koreans who had served in Chinese and Soviet World War II armies made up a large part of his force. He had 8 full divisions, each including a regiment of artillery; 2 divisions at half strength; 2 separate regiments; an armored brigade with 120 Soviet T34 medium tanks; and 5 border constabulary brigades. He also had 180 Soviet aircraft, mostly fighters and attack bombers, and a few naval patrol craft.
The Republic of Korea (ROK) Army had Just 95,000 men and was far less fit. Raised is a constabulary during occupation, it had not in its later combat training, under a U.S. Military Advisor Group progressed much beyond company-level exercises. Of its eight divisions, only four approached full strength. It had no tanks and its artillery totaled eighty-nine 105-mm howitzers. The ROK Navy matched its North Korean counterpart, but the ROK Air Force had only a few trainers and liaison aircraft. U.S. equipment, war-worn when furnished to South Korean forces, had deteriorated further, and supplies on hand could sustain combat operations no longer than fifteen days. Whereas almost $11 million in materiel assistance had been allocated to South Korea in fiscal year 1950 under the Mutual Defense Assistance Program, Congressional review of the allocation so delayed the measure that only a trickle of supplies had reached the country by June 25, 1950.
The North Koreans quickly crushed South Korean defenses at the 38th parallel. The main North Korean attack force next moved down the west side of the peninsula toward Seoul, the South Korean capital, thirty-five miles below the parallel, and entered the city on June 28. Secondary thrusts down the peninsula's center and down the east coast kept pace with the main drive. The South Koreans withdrew in disorder, those troops driven out of Seoul forced to abandon most of their equipment because the bridges over the Han River at the south edge of the city were prematurely demolished. The North Koreans halted after capturing Seoul, but only briefly to regroup before crossing the Han.
In Washington, where a 14-hour time difference made it June 24 when the North Koreans crossed the parallel, the first report of the invasion arrived that night. Early on the 25th, the United States requested a meeting of the U.N. Security Council. The council adopted a resolution that afternoon demanding an immediate cessation of hostilities and a withdrawal of North Korean forces to the 38th parallel.
In independent actions on the night of the 25th, President Truman relayed orders to General of the Army Douglas MacArthur at MacArthur's Far East Command headquarters in Tokyo, Japan, to supply ROK forces with ammunition and equipment, evacuate American dependents from Korea, and survey conditions on the peninsula to determine how best to assist the republic further. The President also ordered the U.S. Seventh Fleet from its current location in Philippine and Ryukyu waters to Japan. On the 26th, in a broad interpretation of a U.N. Security Council request for "every assistance" in supporting the June 25 resolution, President Truman authorized General MacArthur to use air and naval strength against North Korean targets below the 38th parallel. The President also redirected the bulk of the Seventh Fleet to Taiwan, where by standing between the Chinese Communists on the mainland and the Nationalists on the island it could discourage either one from attacking the other and thus prevent a widening of hostilities.
When it became clear on June 27 that North Korea would ignore the U.N. demands, the U.N. Security Council, again at the urging of the United States, asked U.N. members to furnish military assistance to help South Korea repel the invasion. President Truman immediately broadened the range of U.S. air and naval operations to include North Korea and authorized the use of U.S. Army troops to protect Pusan, Korea's major port at the southeastern tip of the peninsula. MacArthur meanwhile had flown to Korea and, after witnessing failing ROK Army efforts in defenses south of the Han River, recommended to Washington that a U.S. Army regiment be committed in the Seoul area at once and that this force be built up to two divisions. President Truman's answer on June 30 authorized MacArthur to use all forces available to him.
Thus the United Nations for the first time since its founding reacted to aggression with a decision to use armed force. The United States would accept the largest share of the obligation in Korea but, still deeply tired of war, would do so reluctantly. President Truman later described his decision to enter the war as the hardest of his days in office. But he believed that if South Korea was left to its own defense and fell, no other small nation would have the will to resist aggression, and Communist leaders would be encouraged to override nations closer to U.S. shores. The American people, conditioned by World War II to battle on a grand scale and to complete victory, would experience a deepening frustration over the Korean conflict, brought on in the beginning by embarrassing reversals on the battlefield.
Ground forces available to MacArthur included the 1st Cavalry Division and the 7th, 24th, and 25th Infantry Divisions, all under the Eighth U.S. Army in Japan, and the 29th Regimental Combat Team on Okinawa. All the postwar depreciations had affected them. Their maneuverability and firepower were sharply reduced by a shortage of organic units and by a general understrength among existing units. Some weapons, medium tanks in particular, could scarcely be found in the Far East, and ammunition reserves amounted to only a 45-day supply. By any measurement, MacArthur's ground forces were unprepared for battle. His air arm, Far East Air Forces (FEAF), moreover, was organized for air defense, not tactical air support. Most FEAF planes were short-range jet interceptors not meant to be flown at low altitudes in support of ground operations. Some F-51's in storage in Japan and more of these World War II planes in the United States would prove instrumental in meeting close air support needs. Naval Forces, Far East, MacArthur's sea arm, controlled only five combat ships and a skeleton amphibious force, although reinforcement was near in the Seventh Fleet.
When MacArthur received word to commit ground units, the main North Korean force already had crossed the Han River. By July 3, a westward enemy attack had captured a major airfield at Kimpo and the Yellow Sea port of Inch'on. Troops attacking south repaired a bridge so that tanks could cross the Han and moved into the town of Suwon, twenty-five miles below Seoul, on the 4th.
The speed of the North Korean drive coupled with the unreadiness of American forces compelled MacArthur to disregard the principle of mass and commit units piecemeal to trade space for time. Where to open a delaying action was clear, for there were few good roads in the profusion of mountains making up the Korean peninsula, and the best of these below Seoul, running on a gentle diagonal through Suwon, Osan, Taejon, and Taegu to the port of Pusan in the southeast, was the obvious main axis of North Korean advance. At MacArthur's order, two rifle companies, an artillery battery, and a few other supporting units of the 24th Division moved into a defensive position astride the main road near Osan, ten miles below Suwon, by dawn on July 5. MacArthur later referred to this 540-man force, called Task Force Smith, as an "arrogant display of strength." Another kind of arrogance to be found at Osan was a belief that the North Koreans might ". . .turn around and go back when they found out who was fighting."
Coming out of Suwon in a heavy rain, a North Korean division supported by thirty-three tanks reached and with barely a pause attacked the Americans around 8:00 a.m. on the 5th. The North Koreans lost 4 tanks, 42 men killed, and 85 wounded. But the American force lacked antitank mines, the fire of its recoilless rifles and 2.36-inch rocket launchers failed to penetrate the T34 armor, and its artillery quickly expended the little antitank ammunition that did prove effective. The rain canceled air support, communications broke down, and the task force was, under any circumstances, too small to prevent North Korean infantry from flowing around both its flanks. By midafternoon, Task Force Smith was pushed into a disorganized retreat with over 150 casualties and the loss of all equipment save small arms. Another casualty was American morale as word of the defeat reached other units of the 24th Division then movin" into delaying positions below Osan.
The next three delaying, actions, though fought by larger forces, had similar results. In each case, North Korean armor or infantry assaults against the front of the American position were accompanied by an infantry double envelopment. By July 13, the 24th Division was forced back on Taejon, sixty miles below Osan, where it initially took position along the Kum River above the town. Clumps of South Korean troops by then were strung out west and east of the division to help delay the North Koreans.
Fifty-three U.N. members meanwhile signified support of the Security Council's June 27 action and twenty-nine of these made specific offers of assistance. Ground, air, and naval forces eventually sent to assist South Korea would represent twenty U.N. members and one nonmember nation. The United States, Great Britain, Australia, New Zealand, Canada, Turkey, Greece, France, Belgium, Luxembourg, the Netherlands, Thailand, the Philippines, Colombia and Ethiopia would furnish ground combat troops. India, Sweden, Norway, Denmark, and Italy (the non-United Nations country) would furnish medical units. Air forces would arrive from the United States, Australia, Canada and the Union of South Africa; naval forces would come from the United States, Great Britain, Australia, Canada, and New Zealand.
The wide response to the council's call pointed out the need for a unified command. Acknowledging the United States as the major contributor, the U.N. Security Council on July 7 asked it to form a command into which all forces would be integrated and to appoint a commander. In the evolving command structure, President Truman became executive agent for the U.N. Security Council. The National Security Council, Department of State, and Joint Chiefs of Staff participated in developing the grand concepts of operations in Korea. In the strictly military channel, the Joint Chiefs issued instructions through the Army member to the unified command in the field, designated the United Nations Command (UNC) and established under General MacArthur.
MacArthur superimposed the headquarters of his new command over that of his existing Far East Command. Air and naval units from other countries joined the Far East Air Forces and Naval Forces, Far East, respectively. MacArthur assigned command of ground troops in Korea to the Eighth Army under Lt. Gen. Walton H. Walker, who established headquarters at Taegu on July 13, assuming command of all American ground troops on the peninsula and, at the request of South Korean President Syngman Rhee, of the ROK Army. When ground forces from other nations reached Korea, they too passed to Walker's command.
Between July 14 and 18, MacArthur moved the 25th and 1st Cavalry Divisions to Korea after cannibalizing the 7th Division to strengten those two units. By then, the battle for Taejon had opened. New 3.5-inch rocket launchers hurriedly airlifted from the United States proved effective against the T34 tanks, but the 24th Division lost Taejon on July 20 after two North Korean divisions established bridgeheads over the Kum River and encircled the town. In running enemy roadblocks during the final withdrawal from town, Maj. Gen. William F. Dean, the division commander, took a wrong turn and was captured some days later in the mountains to the south. When repatriated some three years later, he would learn that for his exploits at Taejon he was one of 131 servicemen awarded the Medal of Honor during the war (Army 78, Marine Corps 42, Navy 7, and Air Force 4).
While pushing the 24th Division below Taejon, the main North Korean force split, one division moving south to the coast, then turning east along the lower coast line. The remainder of the force continued southeast beyond Taejon toward Taegu. Southward advances by the secondary attack forces in the central and eastern sectors matched the main thrust, all clearly aimed to converge on Pusan. North Korean supply lines grew long in the advance, and less and less tenable under heavy UNC air attacks. FEAF meanwhile achieved air superiority, indeed air supremacy, and UNC warships wiped out North Korean naval opposition and clamped a tight blockade on the Korean coast. These achievements and the arrival of the 29th Regimental Combat Team from Okinawa on July 26 notwithstanding, American and South Korean troops steadily gave way. American casualties rose above 6,ooo and South Korean losses reached 70,000. By the beginning of August, General Walker's forces held only a small portion of southeastern Korea.
Alarmed by the rapid loss of ground, Walker ordered a stand along a 140-mile line arching from the Korea Strait to the Sea of Japan west and north of Pusan. His U.S. divisions occupied the western arc, basing their position on the Naktong River. South Korean forces, reorganized by American military advisers into two corps headquarters and five divisions, defended the northern segment. A long line and few troops kept positions thin in this "Pusan Perimeter." But replacements and additional units now entering or on the way to Korea would help relieve the problem, and fair interior lines of communications radiating from Pusan allowed Walker to move troops and supplies with facility.
Raising brigades to division status and conscripting large numbers of recruits, many from overrun regions of South Korea, the North Koreans over the next month and a half committed thirteen infantry divisions and an armored division against Walker's perimeter. But the additional strength failed to compensate for the loss of some 58,000 trained men and much armor suffered in the advance to the Naktong. Nor in meeting the connected defenses of the perimeter did enemy commanders recognize the value of massing forces for decisive penetration at one point. They dissipated their strength instead in piecemeal attacks at various points along the Eighth Army line.
Close air support played a large role in the defense of the perimeter. But the Eighth Army's defense really hinged on a shuttling of scarce reserves to block a gap, reinforce a position, or counterattack wherever the threat appeared greatest at a given moment. Timing was the key, and General Walker proved a master of it. His brilliant responses prevented serious enemy penetrations and inflicted telling losses that steadily drew off North Korean offensive power. His own strength meanwhile was on the rise. By mid-September, he had over 500 medium tanks. Replacements arrived in a steady flow and additional units came in: the 5th Regimental Combat Team from Hawaii, the 2d Infantry Division and 1st Provisional Marine Brigade from the United States, and a British infantry brigade from Hong Kong. Thus, as the North Koreans lost irreplaceable men and equipment, UNC forces acquired an offensive capability.
Against the gloomy prospect of trading space for time, General MacArthur, at the entry of U.S. forces into Korea, had perceived that the deeper the North Koreans drove, the more vulnerable they would become to an amphibious envelopment. He began work on plans for such a blow almost at the start of hostilities, favoring Inch'on, the Yellow Sea port halfway up the west coast, as the landing site. Just twenty-five miles east lay Seoul where Korea's main roads and rail lines converged. A force landing at Inch'on would have to move inland only a short distance to cut North Korean supply routes, and the recapture of the capital city also could have a helpful psychological impact. Combined with a general northward advance by the Eighth Army, a landing at Inch'on could produce decisive results. Enemy troops retiring before the Eighth Army would be cut off by the amphibious force behind them or be forced to make a slow and difficult withdrawal through the mountains farther east.
Though pressed in meeting Eighth Army troop requirements, MacArthur was able to shape a two-division landing force. He formed the headquarters of the X Corps from members of his own staff, naming his chief of staff, Maj. Gen. Edward M. Almond, as corps commander. He rebuilt the 7th Division by giving it high priority on replacements from the United States and by assigning it 8,600 South Korean recruits. The latter measure was part of a larger program, called the Korean Augmentation to the United States Army, in which South Korean troops were placed among almost all American units. At the same time, he acquired from the United States the greater part of the 1st Marine Division, which he planned to fill out with the Marine brigade currently in the Pusan Perimeter. The X Corps, with these two divisions, was to make its landing as a separate force, not as part of the Eighth Army.
MacArthur's superiors and the Navy judged the Inch'on plan dangerous. Naval officers considered the extreme Yellow Sea tides, which range as much as thirty feet, and narrow channel approaches to Inch'on as big risks to shipping. Marine officers saw danger in landing in the middle of a built-up area and in having to scale high sea walls to get ashore. The Joint Chiefs of Staff anticipated serious consequences if Inch'on were strongly defended since MacArthur would be committing his last major reserves at a time when no more General Reserve units in the United States were available for shipment to the Far East. Four National Guard divisions had been federalized on September 1, but none of these was yet ready for combat duty; and, while the draft and call-ups of members of the Organized Reserve Corps were substantially increasing the size of the Army, they offered MacArthur no prospect of immediate reinforcement. But MacArthur was willing to accept the risks.
In light of the uncertainties MacArthur's decision was a remarkable gamble, but if results are what count his action was one of exemplary boldness. The X Corps swept into Inch'on on September 15 against light resistance and, though opposition stiffened, steadily pushed, inland over the next two weeks. One arm struck south and seized Suwon while the remainder of the corps cleared Kimpo Airfield, crossed the Han, and fought through Seoul. MacArthur, with dramatic ceremony, returned the capital city to President Rhee on September 29.
General Walker meanwhile attacked out of the Pusan Perimeter on September 16. His forces gained slowly at first; but on September 23, after the portent of Almond's envelopment and Walker's frontal attack became clear, the North Korean forces broke. The Eighth Army, by then organized as four corps, two U.S. and two ROK, rolled forward in pursuit, linking with the X Corps on September 26. About 30,000 North Korean troops escaped above the 38th parallel through the eastern mountains. Several thousand more bypassed in the pursuit hid in the mountains of South Korea to fight as guerrillas. But by the end of September the North Korea People's Army ceased to exist as an organized force anywhere in the southern republic.