The Korean War (25 June 1950 – 27 July 1953) was an armed conflict fought on the Korean Peninsula between North Korea (Democratic People's Republic of Korea; DPRK) and South Korea (Republic of Korea; ROK) and their allies. North Korea was supported by China and the Soviet Union, while South Korea was supported by the United Nations led by the United States under the auspices of the United Nations Command (UNC).
After the end of World War II in 1945, Korea, which had been a Japanese colony for 35 years, was divided by the Soviet Union and the United States into two occupation zones at the 38th parallel, with plans for a future independent state. The zones formed their own governments in 1948 due to political disagreements. North Korea was led by Kim Il Sung in Pyongyang, and South Korea by Syngman Rhee in Seoul; both claimed to be the sole legitimate government of all of Korea.
Both sides engaged in extensive border clashes while Rhee's government suppressed communist uprisings at Jeju and Yeosu-Suncheon. On 25 June 1950, North Korea launched an invasion of South Korea. In the absence of the Soviet Union's representative, the UN Security Council denounced the invasion, calling on member states to help repel the invasion. UN forces under the unified command comprised 21 countries, with the US providing around 90% of military personnel. On 27 June 1950 President Harry S. Truman ordered US air and sea forces to aid South Korea.
Seoul was captured by the KPA on 28 June, and by early August, the Republic of Korea Army (ROKA) and its allies were nearly defeated, holding onto only the Pusan Perimeter in the peninsula's southeast. On 15 September, UN forces landed at Inchon near Seoul, cutting off KPA troops and supply lines. UN forces broke out from the perimeter on 18 September, recaptured Seoul, and invaded North Korea in October, capturing Pyongyang and advancing towards the Yalu River (border with China). On 19 October, the Chinese People's Volunteer Army (PVA) crossed the Yalu and entered the war on the side of the North. UN forces retreated from North Korea in December, following the PVA's first and second offensive. Communist forces captured Seoul again in January 1951 before losing it to a UN counter-offensive two months later. After an abortive Chinese spring offensive, UN forces retook territory roughly up to the 38th parallel. Armistice negotiations began in July 1951, but dragged on as the fighting became a war of attrition and the North suffered devastating damage from UN bombing, destroying virtually all of North Korea's major cities.
Combat ended on 27 July 1953 with the signing of the Korean Armistice Agreement, which allowed the exchange of prisoners and created a 4-kilometre wide (2.5 mile) Demilitarized Zone (DMZ) along the frontline, with a Joint Security Area at Panmunjom. The industrial warfare was defined by armored offensives, with the North's initial invasion and later by UN forces, tunnel warfare by Chinese forces, and the first large jet aircraft battles. The conflict caused around one million military deaths and an estimated 1.5 million to 3 million civilian deaths. Alleged war crimes include the mass killing of alleged communists by South Korea, the Seoul National University Hospital massacre by North Korea, and the carpet bombing of North Korea by the UNC. North Korea became one of the most heavily bombed countries in history. No peace treaty has been signed; the Korean conflict remains a frozen conflict, which has occasionally flared, such as in the 1966–1969 DMZ Conflict.
Names
In South Korea, the war is usually referred to as the "625 War" (6·25 전쟁; 六二五戰爭; Yugio jeonjaeng), 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.
In North Korea, the war is officially referred to as the "Fatherland Liberation War" (조국해방전쟁; Choguk'aebangjŏnjaeng) or commonly the "Chosŏn [Korean] War" (조선전쟁; Chosŏnjŏnjaeng).
In the United States, the war was initially described by President Harry S. Truman as a "police action" as the US never formally declared war and its military actions in Korea were conducted under the auspices of the UN flag. It has sometimes been referred to in the English-speaking world as "The Forgotten War" or "The Unknown War" because of the lack of public attention it received relative to World War II and the Vietnam War.
In China, the segment of the war after the intervention of the People's Volunteer Army is commonly and officially known as the "War to Resist America and Assist Korea" (Chinese: 抗美援朝战争; pinyin: Kàngměi Yuáncháo Zhànzhēng), while the segment preceding that is officially called the "Korean Civil War" (simplified Chinese: 朝鲜内战; traditional Chinese: 朝鮮內戰; pinyin: Cháoxiǎn Nèizhàn). The term "Chosŏn War" (simplified Chinese: 朝鲜战争; traditional 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 used in Taiwan (Republic of China), Hong Kong and Macau.
Background
Japanese colonization (1910–1945)
Korea was a colony ruled by the Empire of Japan from 1910 to 1945. The Empire of Japan diminished China's influence over Korea in the First Sino-Japanese War (1894–95). A decade later, after defeating Imperial Russia in the Russo-Japanese War, Japan made the Korean Empire its protectorate with the Eulsa Treaty in 1905, and then annexed it with the Japan–Korea Treaty of 1910.
Many Korean nationalists fled the country. The Provisional Government of the Republic of Korea was founded in 1919 in the Beiyang government. It failed to achieve international recognition, failed to unite the nationalist groups, and had a fractious relationship with its US-based founding president, Syngman Rhee.
The Chinese 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 (1941–1945). The communists, led by Kim Il Sung, among others, fought the Japanese in Korea and Manchuria.
At the Tehran Conference in 1943 and the Yalta Conference in February 1945, the Soviet Union promised to join the Allies in the Pacific War within three months of the victory in Europe. On 8 August 1945, the USSR declared war on Japan and invaded Manchuria. On 10 August, Soviet forces entered northern Korea and had secured most major cities in the north by 24 August, as Japanese resistance was light. Having fought Japan on Korean soil, the Soviet forces were well received by Koreans. Imperial Japanese rule of Korea officially ended when Japan surrendered to the Allies on 15 August 1945, following the atomic bombings of Hiroshima and Nagasaki.
Division of Korea (1945)
At the Cairo Conference in 1943, China, the UK, and the US decided that "in due course, Korea shall become free and independent".
As World War II drew to a close, on 11 August 1945 two American military officials in Washington – US Colonels Dean Rusk and Charles H. Bonesteel III – chose an invisible line across the former Japanese colony, the 38th Parallel, for the division of Korea into two occupation zones, north and south, Soviet and American.
This was incorporated into US General Order No. 1, which responded to the Japanese surrender on 15 August. Joseph Stalin, however, maintained his wartime policy of cooperation, and on 16 August, the Red Army halted at the 38th parallel for three weeks to await the arrival of US forces. In explaining the choice of the 38th parallel, US Colonel Dean Rusk observed that, "Even though it was further north than could be realistically reached by US 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".
Joint US-Soviet occupation (1945–1948)
On 7 September 1945, General Douglas MacArthur issued Proclamation No. 1 to the people of Korea, announcing US military control over Korea south of the 38th parallel and establishing English as the official language during military control. On 8 September, US Lieutenant General John R. Hodge arrived in Incheon to accept the Japanese surrender south of the 38th parallel. Appointed as military governor, Hodge directly controlled South Korea as head of the US Army Military Government in Korea (USAMGIK 1945–48).
In December 1945, Korea was administered by the US–Soviet Union Joint Commission, as agreed at the Moscow Conference, to grant independence after a five-year trusteeship. Waiting five years for independence was unpopular among Koreans, and riots broke out. The Communist Party supported the trusteeship, while Kim Ku and Syngman Rhee led the anti-trusteeship movement against both the US Army Military Government in Korea and the Soviet military administration. To contain them, the USAMGIK banned strikes on 8 December and outlawed the PRK Revolutionary Government and People's Committees on 12 December. Following further civilian unrest, the USAMGIK declared martial law.
Citing the inability of the Joint Commission to make progress, the United Nations (UN) decided to hold an election under UN auspices to create an independent Korea, as stated in UN General Assembly Resolution 112. The Soviet authorities and Korean communists refused to participate in the election. The final attempt to establish a unified government was thwarted by North Korea's refusal. Due to concerns about division caused by an election without North Korea's participation, many South Korean politicians boycotted it. The 1948 South Korean general election was held in May. 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 Soviets agreed to the establishment of a communist government led by Kim Il Sung. The Democratic People's Republic of Korea (North Korea) was established on 10 July 1948. The 1948 North Korean parliamentary elections took place in August. The Soviet Union withdrew its forces in 1948 and the US in 1949.
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.
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. North Korea also provided the Chinese Communists in Manchuria with a safe refuge for non-combatants and communications with the rest of China. As a token of gratitude, between 50,000 and 70,000 Korean veterans who 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. China promised to support the North Koreans in the event of a war against South Korea.
Communist insurgency in South Korea (1948–1950)
By 1948, a North Korea-backed insurgency had broken out in the southern half of the peninsula. This was exacerbated by the undeclared border war between the Koreas, which saw division-level engagements and thousands of deaths on both sides. The ROK 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 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. Approximately 8,000 South Korean soldiers and police officers died in the insurgent war and border clashes.
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 Jeju Island, the campaign saw arrests and repression by the South Korean government in the fight against the South Korean Labor Party, resulting in 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 by 2,400 KPA commandos who had infiltrated through the border, these guerrillas launched an offensive in September aimed at undermining the South Korean government and preparing the country for the KPA's arrival in force. This offensive failed. However, the guerrillas were now entrenched in the Taebaek-san region of the North Gyeongsang Province and the border areas of the Gangwon Province.
While the insurgency was ongoing, the ROKA and KPA engaged in battalion-sized battles along the border, starting in May 1949. 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 attacks in Kuksa-bong, and KPA troops were "completely routed". Border incidents decreased by the start of 1950.
Meanwhile, counterinsurgencies in the South Korean interior intensified; persistent operations, paired with worsening weather, denied the guerrillas sanctuary and wore away their fighting strength. North Korea responded by sending more troops to link up with insurgents and build more partisan cadres; North Korean infiltrators had reached 3,000 soldiers in 12 units by the start of 1950, but all were destroyed or scattered by the ROKA.
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, North Korea made final attempts to keep the uprising active, sending battalion-sized units of infiltrators under the commands of Kim Sang-ho and Kim Moo-hyon. The first battalion was reduced to a single man over the course of engagements by the ROKA 8th Division. The second was annihilated by a two-battalion hammer-and-anvil maneuver by units of the ROKA 6th Division, resulting in a toll of 584 KPA guerrillas (480 killed, 104 captured) and 69 ROKA troops killed, plus 184 wounded. By the spring of 1950, guerrilla activity had mostly subsided; the border, too, was calm.