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Korean War
Part of the Cold War and the Korean conflict
Clockwise from top: A column of the U.S. 1st Marine Division's infantry and armor moves through Chinese lines during their breakout from the Chosin Reservoir UN landing at Inchon harbor, starting point of the Battle of Inchon Korean refugees in front of a U.S. M46 Patton tank The Seoul city gate Namdaemun, damaged Explosion during the Blockade of Wonsan
Date 25 June 1950 – 27 July 1953 (de facto) (3 years, 1 month and 2 days) 25 June 1950 – present (de jure) (73 years, 6 months and 2 weeks) Location Korean Peninsula, Yellow Sea, Sea of Japan, Korea Strait, China–North Korea border Result Inconclusive Territorial changes Korean Demilitarized Zone established North Korea gains the city of Kaesong, but loses a net total of 3,900 km2 (1,506 sq mi), including the city of Sokcho, to South Korea[16]
Belligerents
South Korea	North Korea
United Nations[a]  United States  United Kingdom  Canada  Turkey  Australia  Philippines  New Zealand Thailand  Ethiopia  Greece  France  Colombia  Belgium  South Africa  Netherlands  Luxembourg Medical support:[5]  Sweden  India  Denmark  Norway  Italy[b][3]  West Germany[4] Other support:  Israel[6]  Taiwan  Japan[7] Pakistan[8]  Uruguay[9]  El Salvador  Spain[10]  Yugoslavia[11]	China  Soviet Union (unofficial) Supported by:  Bulgaria  Czechoslovakia[12]  East Germany[13]  Hungary[13][14]  Mongolia  Poland  Romania[15]
Commanders and leaders
Syngman Rhee Chung Il-kwon Paik Sun-yup Lee Hyung-geun Shin Sung-mo	Kim Il Sung Kim Tu-bong Pak Hon-yong Choe Yong-gon Kim Chaek †
Trygve Lie Dag Hammarskjöld Harry S. Truman Dwight D. Eisenhower George C. Marshall Robert A. Lovett Douglas MacArthur Matthew Ridgway Mark W. Clark Walton Walker James Van Fleet Clement Attlee Winston Churchill	Mao Zedong Zhou Enlai Peng Dehuai Chen Geng Deng Hua Hong Xuezhi Song Shilun Han Xianchu Joseph Stalin Pavel Zhigarev
Strength
Peak strength (combat troops): 602,902[17] 326,863[18] 14,198[19][20] 8,123[21] 5,455[22] 2,282[19] 2,274[22] 1,496[19] 1,389[22] 1,271[23] 1,263[19][23] 1,185[23] 1,068 [22] 900[19] 826[19] 819[19] 52[22] Medical support and others: 346[24] 170[22] 120[7] 109[22] 100[22] 72[22] Together: 968,302 Total strength[25][26] (combat troops): 1,789,000[27] 1,300,000[28] 56,000 26,791 21,212 17,164 7,420 6,326 5,322 5,100 4,992 3,794 3,518 3,498 3,421 826 100 Medical support and others: 1,124 630 627 623 189 120 Together: 3,257,797	Peak strength (combat troops): 266,600[29] 1,450,000[30][31] 26,000[32] Together: 1,742,000 Total: 2,970,000[33] 72,000[32] Together: 3,042,000
Casualties and losses
Total civilian deaths: 2–3 million (est.)[34][35] South Koreans: 990,968 total casualties[22] North Koreans: 1,550,000 total casualties (est.)[22]

The Korean War was fought between North Korea and South Korea from 1950 to 1953. The war began on 25 June 1950 when North Korea invaded South Korea following years of hostilities between the two countries. North Korea was supported by China and the Soviet Union while South Korea was supported by the United States and allied countries. The fighting ended with an armistice on 27 July 1953.

In 1910, the Empire of Japan annexed Korea as a colony for 35 years until its surrender at the end of World War II on 15 August 1945.^[c] The United States and the Soviet Union divided Korea along the 38th parallel into two zones of occupation. The Soviets administered the northern zone, and the Americans administered the southern zone. In 1948, as a result of Cold War tensions, the occupation zones became two sovereign states. A communist state, the Democratic People's Republic of Korea, was established in the north under the government led by Premier Kim Il Sung, while a democracy, the Republic of Korea, was established in the south under the government led by President Syngman Rhee. Both governments claimed to be the sole legitimate government of all of Korea and neither accepted the border as permanent.

The years prior to North Korea's invasion of South Korea were marked by border clashes between the two countries and an insurgency in the South that was backed by the North.^[36][37][38] After failed attempts to stop the fighting and unify the Koreas, North Korean forces (Korean People's Army or KPA) crossed the 38th parallel on 25 June 1950, formally starting the war.^[39][40] The United Nations Security Council denounced North Korea's actions and authorized the formation of the United Nations Command and the dispatch of forces to Korea^[41] to repel it.^[42][43] The Soviet Union was boycotting the UN for recognizing Taiwan (Republic of China) as China,^[44] and the People's Republic of China was not recognized by the UN, so neither could support their ally North Korea at the Security Council meeting. Twenty-one countries of the United Nations eventually contributed to the UN force, with the United States providing around 90% of the military personnel,^[45] and represented the first attempt at collective security under the United Nations system.^[46]

After the first two months of war, the South Korean army (ROKA) and hastily dispatched American forces were on the point of defeat, retreating to a small area behind a defensive line known as the Pusan Perimeter. In September 1950, a risky amphibious UN counteroffensive was launched at Incheon, cutting off KPA troops and supply lines in South Korea. Those who escaped envelopment and capture were forced back north. UN forces then invaded North Korea in October 1950 and moved rapidly towards the Yalu River—the border with China—but on 19 October 1950, Chinese forces - the People's Volunteer Army (PVA) - crossed the Yalu and entered the war.^[39] The UN retreated from North Korea following the PVA's First Phase Offensive and the Second Phase Offensive. China along with their North Korean and Soviet allies pressed their offensive, invading the South and capturing Seoul by early January 1951. A UN force recaptured the city from them, and the communist forces were pushed back to positions around the 38th parallel following PVA's abortive Fifth Phase Offensive. After this, the front which was close to where the war had started stabilized, and the last two years were a war of attrition.

The fighting ended on 27 July 1953 when the Korean Armistice Agreement was signed. The agreement created the Korean Demilitarized Zone (DMZ) to separate North and South Korea, and allowed the return of prisoners. However, no peace treaty was ever signed, and the two Koreas are technically still at war, engaged in a frozen conflict.^[47][48] In April 2018, the leaders of North and South Korea met at the DMZ^[49] and agreed to work toward a treaty to end the Korean War formally.^[50]

The Korean War was a major conflict of the Cold War and among the most destructive conflicts of the modern era, with approximately 3 million war fatalities and a larger proportional civilian death toll than World War II or the Vietnam War. It resulted in the destruction of virtually all of Korea's major cities, with thousands of massacres committed by both sides—including the mass killing of tens of thousands of suspected communists by the South Korean government, and the torture and starvation of prisoners of war by the North Koreans. North Korea became among the most heavily bombed countries in history.^[51] Over the course of the war 1.5 million North Koreans are estimated to have fled North Korea.^[52]

Names

In South Korea, the war is usually referred to as the "625 War" (6·25 전쟁; 六二五戰爭), the "625 Upheaval" (6·25 동란; 六二五動亂; yugio dongnan), or simply "625", reflecting the date of its commencement on 25 June.^[53]

In North Korea, the war is officially referred to as the "Fatherland Liberation War" (Choguk haebang chŏnjaeng) or alternatively the "Chosŏn War" (조선전쟁; Chosŏn chŏnjaeng).^[54]

In mainland China, the segment of the war after the intervention of the People's Volunteer Army is most commonly and officially known as the "Resisting America and Assisting Korea War"^[55] (Chinese: 抗美援朝战争; pinyin: Kàngměi Yuáncháo Zhànzhēng), although the term "Chosŏn War" (Chinese: 朝鮮戰爭; pinyin: Cháoxiǎn Zhànzhēng) is sometimes used unofficially. The term "Hán (Korean) War" (Chinese: 韓戰; pinyin: Hán Zhàn) is most commonly used in Taiwan (Republic of China), Hong Kong and Macau.

In the U.S., the war was initially described by President Harry S. Truman as a "police action", as the United States never formally declared war on its opponents, and the operation was conducted under the auspices of the United Nations.^[56] It has been sometimes referred to in the English-speaking world as "The Forgotten War" or "The Unknown War" because of the lack of public attention it received both during and after the war, relative to the global scale of World War II, which preceded it, and the subsequent angst of the Vietnam War, which succeeded it.^[57][58]

Background

Imperial Japanese rule (1910–1945)

Imperial Japan severely diminished the influence of China over Korea in the First Sino-Japanese War (1894–95), ushering in the short-lived Korean Empire.^[59] A decade later, after defeating Imperial Russia in the Russo-Japanese War (1904–05), Japan made the Korean Empire its protectorate with the Eulsa Treaty in 1905, then annexed it with the Japan–Korea Annexation Treaty in 1910. After that, the Korean Empire fell, and Korea was directly ruled by Japan from 1910 to 1945.^[60]

Many Korean nationalists fled the country. The Provisional Government of the Republic of Korea was founded in 1919 in Nationalist China. It failed to achieve international recognition, failed to unite the various nationalist groups, and had a fractious relationship with its U.S.-based founding president, Syngman Rhee.^[61] From 1919 to 1925 and beyond, Korean communists led internal and external warfare against the Japanese.^[62][63]

In China, the nationalist National Revolutionary Army and the communist People's Liberation Army (PLA) helped organize Korean refugees against the Japanese military, which had also occupied parts of China. The Nationalist-backed Koreans, led by Yi Pom-Sok, fought in the Burma campaign (December 1941 – August 1945). The communists, led by, among others, Kim Il Sung, fought the Japanese in Korea and Manchuria.^[64]

At the Cairo Conference in November 1943, China, the United Kingdom and the United States all decided that "in due course Korea shall become free and independent".^[65]

Korea divided (1945–1949)

At the Tehran Conference in November 1943 and the Yalta Conference in February 1945, the Soviet Union promised to join its allies in the Pacific War within three months of the victory in Europe. Germany officially surrendered on 8 May 1945, and the USSR declared war on Japan and invaded Manchuria on 8 August 1945, three months later. This was three days after the atomic bombing of Hiroshima.^[63][66] By 10 August, the Red Army had begun to occupy the north of Korea.^[67]

On the night of 10 August in Washington, U.S. Colonels Dean Rusk and Charles H. Bonesteel III were assigned to divide Korea into Soviet and U.S. occupation zones and proposed the 38th parallel as the dividing line. This was incorporated into the U.S. General Order No. 1, which responded to the Japanese surrender on 15 August. Explaining the choice of the 38th parallel, Rusk observed, "even though it was further north than could be realistically reached by U. S. forces in the event of Soviet disagreement ... we felt it important to include the capital of Korea in the area of responsibility of American troops". He noted that he was "faced with the scarcity of U.S. forces immediately available and time and space factors which would make it difficult to reach very far north before Soviet troops could enter the area".^[68][69] As Rusk's comments indicate, the U.S. doubted whether the Soviet government would agree to this.^{[70][71][72][73]} Soviet leader Joseph Stalin, however, maintained his wartime policy of co-operation, and on 16 August the Red Army halted at the 38th parallel for three weeks to await the arrival of U.S. forces in the south.^[67]

On 7 September 1945, General Douglas MacArthur issued Proclamation No. 1 to the people of Korea, announcing U.S. military control over Korea south of the 38th parallel and establishing English as the official language during military control.^[74] On 8 September U.S. Lieutenant General John R. Hodge arrived in Incheon to accept the Japanese surrender south of the 38th parallel.^[71] Appointed as military governor, Hodge directly controlled South Korea as head of the United States Army Military Government in Korea (USAMGIK 1945–48).^[75]

In December 1945, Korea was administered by a U.S.–Soviet Union Joint Commission, as agreed at the Moscow Conference, with the aim of granting independence after a five-year trusteeship.^[76][77] The idea (to have to wait 5 years for independence) was not popular among Koreans, and riots broke out.^[60] To contain them, the USAMGIK banned strikes on 8 December and outlawed the PRK Revolutionary Government and the PRK People's Committees on 12 December.^[78] Following further large-scale civilian unrest,^[79] the USAMGIK declared martial law.

Citing the inability of the Joint Commission to make progress, the U.S. government decided^[when?] to hold an election under United Nations auspices with the aim of creating an independent Korea. The Soviet authorities and the Korean communists refused to co-operate on the grounds that it would not be fair, and many South Korean politicians boycotted it.^[80][81] A general election was held in the South on 10 May 1948.^[82][83] North Korea held parliamentary elections three months later on 25 August.^[84] The resultant South Korean government promulgated a national political constitution on 17 July and elected Syngman Rhee as president on 20 July. The Republic of Korea (South Korea) was established on 15 August 1948. In the Soviet Korean Zone of Occupation, the Soviet Union agreed to the establishment of a communist government^[82] led by Kim Il Sung.^[85]

The Soviet Union withdrew its forces from Korea in 1948, and U.S. troops withdrew in 1949.^[86][87]

Chinese Civil War (1945–1949)

With the end of the war with Japan, the Chinese Civil War resumed in earnest between the Communists and the Nationalist-led government. While the Communists were struggling for supremacy in Manchuria, they were supported by the North Korean government with matériel and manpower.^[88] According to Chinese sources, the North Koreans donated 2,000 railway cars worth of supplies while thousands of Koreans served in the Chinese PLA during the war.^[89] North Korea also provided the Chinese Communists in Manchuria with a safe refuge for non-combatants and communications with the rest of China.^[88]

The North Korean contributions to the Chinese Communist victory were not forgotten after the creation of the People's Republic of China (PRC) in 1949. As a token of gratitude, between 50,000 and 70,000 Korean veterans that served in the PLA were sent back along with their weapons, and they later played a significant role in the initial invasion of South Korea.^[88] China promised to support the North Koreans in the event of a war against South Korea.^[90]

Communist insurgency in South Korea (1948–1950)

By 1948, a large-scale, North Korea-backed insurgency had broken out in the southern half of the peninsula. This was exacerbated by the ongoing undeclared border war between the Koreas, which saw division-level engagements and thousands of deaths on both sides.^[91] The ROK in this time was almost entirely trained and focused on counterinsurgency, rather than conventional warfare. They were equipped and advised by a force of a few hundred American officers, who were largely successful in helping the ROKA to subdue guerrillas and hold its own against North Korean military (Korean People's Army, KPA) forces along the 38th parallel.^[92] Approximately 8,000 South Korean soldiers and police died in the insurgent war and border clashes.^[93]

The first socialist uprising occurred without direct North Korean participation, though the guerrillas still professed support for the northern government. Beginning in April 1948 on the isolated island of Jeju, the campaign saw mass arrests and repression by the South Korean government in the fight against the South Korean Labor Party, resulting in a total of 30,000 violent deaths, among them 14,373 civilians (of whom ~2,000 were killed by rebels and ~12,000 by ROK security forces). The Yeosu–Suncheon rebellion overlapped with it, as several thousand army defectors waving red flags massacred right-leaning families. This resulted in another brutal suppression by the government and between 2,976 and 3,392 deaths. By May 1949, both uprisings had been crushed.

Insurgency reignited in the spring of 1949 when attacks by guerrillas in the mountainous regions (buttressed by army defectors and North Korean agents) increased. Insurgent activity peaked in late 1949 as the ROKA engaged so-called People's Guerrilla Units. Organized and armed by the North Korean government, and backed up by 2,400 KPA commandos who had infiltrated through the border, these guerrillas launched a large offensive in September aimed at undermining the South Korean government and preparing the country for the KPA's arrival in force. This offensive failed.^[94] However, by this point, the guerrillas were firmly entrenched in the Taebaek-san region of the North Gyeongsang Province (around Taegu), as well as in the border areas of the Gangwon Province.^[95]

While the insurgency was ongoing, the ROKA and KPA engaged in multiple battalion-sized battles along the border, starting in May 1949.^[92] Serious border clashes between South and North continued on 4 August 1949, when thousands of North Korean troops attacked South Korean troops occupying territory north of the 38th parallel. The 2nd and 18th ROK Infantry Regiments repulsed initial attacks in Kuksa-bong (above the 38th parallel),^[96] and at the end of the clashes ROK troops were "completely routed".^[97] Border incidents decreased significantly by the start of 1950.^[95]

Meanwhile, counterinsurgency efforts in the South Korean interior intensified; persistent operations, paired with worsening weather conditions, eventually denied the guerrillas sanctuary and wore away their fighting strength. North Korea responded by sending more troops to link up with existing insurgents and build more partisan cadres; the number of North Korean infiltrators had reached 3,000 soldiers in 12 units by the start of 1950, but all of these units were destroyed or scattered by the ROKA.^[98] On 1 October 1949, the ROKA launched a three-pronged assault on the insurgents in South Cholla and Taegu. By March 1950, the ROKA claimed 5,621 guerrillas killed or captured and 1,066 small arms seized. This operation crippled the insurgency. Soon after, the North Koreans made two final attempts to keep the uprising active, sending two battalion-sized units of infiltrators under the commands of Kim Sang-ho and Kim Moo-hyon. The first battalion was reduced in annihilation to a single man over the course of several engagements by the ROKA 8th Division. The second battalion was annihilated by a two-battalion hammer-and-anvil maneuver by units of the ROKA 6th Division, resulting in a loss toll of 584 KPA guerrillas (480 killed, 104 captured) and 69 ROKA troops killed, plus 184 wounded.^[99] By spring of 1950, guerrilla activity had mostly subsided; the border, too, was calm.^[100]

Prelude to war (1950)

By 1949, South Korean and U.S. military actions had reduced the active number of indigenous communist guerrillas in the South from 5,000 to 1,000. However, Kim Il Sung believed that widespread uprisings had weakened the South Korean military and that a North Korean invasion would be welcomed by much of the South Korean population. Kim began seeking Stalin's support for an invasion in March 1949, traveling to Moscow to attempt to persuade him.^[101]

Stalin initially did not think the time was right for a war in Korea. PLA forces were still embroiled in the Chinese Civil War, while U.S. forces remained stationed in South Korea.^[102] By spring 1950, he believed that the strategic situation had changed: PLA forces under Mao Zedong had secured final victory in China, U.S. forces had withdrawn from Korea, and the Soviets had detonated their first nuclear bomb, breaking the U.S. atomic monopoly. As the U.S. had not directly intervened to stop the communist victory in China, Stalin calculated that they would be even less willing to fight in Korea, which had much less strategic significance.^[103] The Soviets had also cracked the codes used by the U.S. to communicate with their embassy in Moscow, and reading these dispatches convinced Stalin that Korea did not have the importance to the U.S. that would warrant a nuclear confrontation.^[103] Stalin began a more aggressive strategy in Asia based on these developments, including promising economic and military aid to China through the Sino-Soviet Treaty of Friendship, Alliance, and Mutual Assistance.^[104]

In April 1950, Stalin gave Kim permission to attack the government in the South under the condition that Mao would agree to send reinforcements if needed.^[105] For Kim, this was the fulfilment of his goal to unite Korea after its division by foreign powers. Stalin made it clear that Soviet forces would not openly engage in combat, to avoid a direct war with the U.S.^[105] Kim met with Mao in May 1950 and differing historical interpretations of the outcome of the meeting have been put forward. According to Barbara Barnouin and Yu Changgeng, Mao agreed to support Kim despite concerns of American intervention, as China desperately needed the economic and military aid promised by the Soviets.^[106] Kathryn Weathersby cites Soviet documents which said Kim secured Mao's support.^[107] Along with Mark O'Neill, she says this accelerated Kim's war preparations.^[108][109] Chen Jian argues Mao never seriously challenged Kim’s plans and that Kim had every reason to inform Stalin that he had obtained Mao's support.^[110]: 112 Citing recent scholarship, Zhao Suisheng contends Mao did not approve of Kim's war proposal and requested verification from Stalin which he provided via a telegram.^{[111]: 28–9} Mao accepted the decision made by Kim and Stalin to unify the Koreas but cautioned Kim over possible US intervention.^[111]: 30

Soviet generals with extensive combat experience from the Second World War were sent to North Korea as the Soviet Advisory Group. These generals completed the plans for the attack by May.^[112] The original plans called for a skirmish to be initiated in the Ongjin Peninsula on the west coast of Korea. The North Koreans would then launch an attack that would capture Seoul and encircle and destroy the ROK. The final stage would involve destroying South Korean government remnants and capturing the rest of South Korea, including the ports.^[113]

On 7 June 1950, Kim called for a Korea-wide election on 5–8 August 1950 and a consultative conference in Haeju on 15–17 June. On 11 June, the North sent three diplomats to the South as a peace overture which Rhee rejected outright.^[105] On 21 June, Kim revised his war plan to involve a general attack across the 38th parallel, rather than a limited operation in the Ongjin Peninsula. Kim was concerned that South Korean agents had learned about the plans and that South Korean forces were strengthening their defenses. Stalin agreed to this change of plan.^[114]

While these preparations were underway in the North, there were frequent clashes along the 38th parallel, especially at Kaesong and Ongjin, many initiated by the South.^[37][38] The ROK was being trained by the U.S. Korean Military Advisory Group (KMAG). On the eve of war, KMAG commander General William Lynn Roberts voiced utmost confidence in the ROK and boasted that any North Korean invasion would merely provide "target practice".^[115] For his part, Syngman Rhee repeatedly expressed his desire to conquer the North, including when U.S. diplomat John Foster Dulles visited Korea on 18 June.^[116]

Although some South Korean and U.S. intelligence officers predicted an attack from the North, similar predictions had been made before and nothing had happened.^[117] The Central Intelligence Agency noted the southward movement by the KPA but assessed this as a "defensive measure" and concluded an invasion was "unlikely".^[118] On 23 June UN observers inspected the border and did not detect that war was imminent.^[119]

Comparison of forces

Throughout 1949 and 1950, the Soviets continued arming North Korea. After the communist victory in the Chinese Civil War, ethnic Korean units in the PLA were sent to North Korea.^[120] Chinese involvement was extensive from the beginning, building on previous collaboration between the Chinese and Korean communists during the Chinese Civil War. In the fall of 1949, two PLA divisions composed mainly of Korean-Chinese troops (the 164th and 166th) entered North Korea, followed by smaller units throughout the rest of 1949; these troops brought with them not only their experience and training, but also their weapons and other equipment, changing little but their uniforms. The reinforcement of the KPA with PLA veterans continued into 1950, with the 156th Division and several other units of the former Fourth Field Army arriving (also with their equipment) in February; the PLA 156th Division was reorganized as the KPA 7th Division. By mid-1950, between 50,000 and 70,000 former PLA troops had entered North Korea, forming a significant part of the KPA's strength on the eve of the war's beginning.^[121] Several generals, such as Lee Kwon-mu, were PLA veterans born to ethnic Koreans in China. The combat veterans and equipment from China, the tanks, artillery and aircraft supplied by the Soviets, and rigorous training increased North Korea's military superiority over the South, armed by the U.S. military with mostly small arms, but no heavy weaponry such as tanks.^[122] While older histories of the conflict often referred to these ethnic Korean PLA veterans as being sent from northern Korea to fight in the Chinese Civil War before being sent back, recent Chinese archival sources studied by Kim Donggill indicate that this was not the case. Rather, the soldiers were indigenous to China (part of China's longstanding ethnic Korean community) and were recruited to the PLA in the same way as any other Chinese citizen.^[123]

According to the first official census in 1949, the population of North Korea numbered 9,620,000,^[124] and by mid-1950, North Korean forces numbered between 150,000 and 200,000 troops, organized into 10 infantry divisions, one tank division, and one air force division, with 210 fighter planes and 280 tanks, who captured scheduled objectives and territory, among them Kaesong, Chuncheon, Uijeongbu and Ongjin. Their forces included 274 T-34-85 tanks, 200 artillery pieces, 110 attack bombers, and some 150 Yak fighter planes, and 35 reconnaissance aircraft. In addition to the invasion force, the North had 114 fighters, 78 bombers, 105 T-34-85 tanks, and some 30,000 soldiers stationed in reserve in North Korea.^[71] Although each navy consisted of only several small warships, the North and South Korean navies fought in the war as seaborne artillery for their armies.

In contrast, the South Korean population was estimated at 20 million,^[125] but its army was unprepared and ill-equipped. As of 25 June 1950, the ROK had 98,000 soldiers (65,000 combat, 33,000 support), no tanks (they had been requested from the U.S. military, but requests were denied), and a 22-plane air force comprising 12 liaison-type and 10 AT-6 advanced-trainer airplanes. Large U.S. garrisons and air forces were in Japan,^[126] but only 200–300 U.S. troops were in Korea.^[127]

Course of the war

Operation Pokpung

At dawn on 25 June 1950, the KPA crossed the 38th parallel behind artillery fire.^[128] The KPA justified its assault with the claim that ROK troops attacked first and that the KPA were aiming to arrest and execute the "bandit traitor Syngman Rhee".^[129] Fighting began on the strategic Ongjin Peninsula in the west.^[130][131] There were initial South Korean claims that the 17th Regiment had counterattacked at Haeju; some scholars argue the claimed counterattack was instead the instigating attack, and therefore that the South Koreans may have fired first.^[130][132] However, the report that contained the Haeju claim also contained numerous other errors and outright falsehoods.^[133]

Whoever fired the first shots in Ongjin, KPA forces attacked all along the 38th parallel within an hour. The KPA had a combined arms force including tanks supported by heavy artillery. The ROK had no tanks, anti-tank weapons or heavy artillery to stop such an attack. In addition, the South Koreans committed their forces in a piecemeal fashion, and these were routed in a few days.^[134]

On 27 June, Rhee evacuated Seoul with some of the government. At 02:00 on 28 June the ROK blew up the Hangang Bridge across the Han River in an attempt to stop the KPA. The bridge was detonated while 4,000 refugees were crossing it, and hundreds were killed.^[135][136] Destroying the bridge also trapped many ROK units north of the Han River.^[134] In spite of such desperate measures, Seoul fell that same day. A number of South Korean National Assemblymen remained in Seoul when it fell, and 48 subsequently pledged allegiance to the North.^[137]

On 28 June, Rhee ordered the massacre of suspected political opponents in his own country.^[138] In five days, the ROK, which had 95,000 troops on 25 June, was down to less than 22,000 troops. In early July, when U.S. forces arrived, what was left of the ROK was placed under U.S. operational command of the United Nations Command.^[139]

Factors in U.S. intervention