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An armed conflict fought between countries or non-state actors on behalf of other powers not directly involved.
Korean War dates
The Korean War was fought from 25 June 1950 – 27 July 1953, when an armistice was signed between North Korea, China, and the United States. However, South Korea did not agree to this armistice and no formal peace treaty has ever been signed, so technically the Korean War never ended.
Fig. 1 - Korean War illustration
Background of the Korean War
Let’s look at what was going on in Korea before the Korean War in order to fully understand the causes of the war.
Imperial Japanese rule: 1910–45
Korea had been part of Japan since 1910 after it was annexed in the Japan–Korea Annexation Treaty. Imperial Japanese rule led to many Korean nationalists fleeing the country and installing the Provisional Government of the Republic of Korea in China in 1919. This government failed. It did not receive international support; it did not unite Koreans; and its founder, Syngman Rhee, was based in the United States for the majority of his time as President, making it more difficult for him to remain in touch with what was happening in Korea.
In China, Korean refugees were organised to fight against the Japanese military thanks to the Nationalist Chinese National Revolutionary Army and the Communist Chinese People's Liberation Army (PLA). Between 1919 and 1945, Korean nationalists fought the Japanese through direct and indirect warfare. Led by Yi Pom-Sok, they took part in the Burma Campaign (1941–45) and fought the Japanese in Korea and Manchuria.
At the Cairo Conference in November 1943, the United Kingdom and the United States met with the President of China to discuss securing the surrender of Japan and plans for post-war Asia. Regarding Korea, the three powers declared that:
in due course Korea shall become free and independent.
Dividing Korea
In February of 1945, at the Yalta Conference, the Soviet Union agreed to join the United States in the Pacific War to defeat Japan once Germany had surrendered. When the USSR entered into the war against Japan on 8 August 1945, it promised to support the independence of Korea. The Soviets first invaded Manchuria and by 10 August, the Red Army occupied the north of Korea.
By this time, US Colonels in Washington had been assigned to divide Korea into two different occupation zones: one for the Soviet Union and one for the United States. It was divided into a Northern and Southern zone; the dividing line is known as Parallel 38. Soviet leader Joseph Stalin respected his wartime alliance and cooperated: his troops halted at the 38th Parallel on 16 August and waited three weeks for US troops to arrive from the South.
Fig. 2 Members participating in a Jewish worship service in the field during the Korean War
The US government then decided to hold an election in order to create an independent and unified Korea in 1948 but the USSR and Korean communists refused.
A general election was held in the South on 10 May 1948. The South Korean government then published a national political constitution two months later, and Syngman Rhee was elected as President. The Republic of Korea was established on 15 August 1948. In the Soviet zone, a communist government led by Kim Il-sung was established.
In 1948, the USSR withdrew its troops from Korea, followed by the US in 1949.
Immediate causes of the Korean War
Korea was now divided between the non-communist, American-backed South Korea under the leadership of Syngman Rhee - an anti-communist statesman, and the Soviet-backed communist North Korea, ruled by Kim Il-Sung - a dictator. How did this situation transpire into war?
North Korean attacks
Many South Koreans believed that the Rhee regime was corrupt and had manipulated the election of 1948 in order to win it. This made Syngman Rhee an extremely unpopular leader and he fared badly in the April 1950 elections. Many in the South voted for reunification with the North.
This caused North Korea to launch an attack on South Korea on 25 June 1950, with the support of China and the Soviet Union. More than 80,000 North Korean troops invaded and captured the South Korean capital, Seoul, in just 3 days. The Korean War had only just begun…
Korean War combatants
As we have mentioned, the Korean War was not simply a war between North and South Korea. The involvement of other countries was influential on the beginning and course of the Korean War.
| Combatant | Motives |
United States | Domino TheoryAs North Korea invaded practically the whole of South Korea, including its capital, the United States was desperate to not only contain the spread of communism but also prevent the domino effect. Harry Truman, the US president at the time, was worried that if Korea fell to communism, other countries in Asia would fall, which would be catastrophic for America and for capitalism.
The Truman DoctrineThe Truman doctrine (named after President Harry Truman) was the name of an American foreign policy introduced in 1947 which declared that the US would help any country under the threat of communism and authoritarianism. In this case, South Korea was invaded by communist forces, so the US came to its aid. Other factors
|
The Soviet Union | Spread of communismThe Soviet Union believed in spreading communism across the world. Since Kim-Il Sung was attempting to do this with South Korea, Stalin felt it was necessary to help him. At the same time, the UN was sending help to South Korea, so the USSR had to counter this by helping North Korea. Avoiding direct confrontation with the USStalin wanted to expand communism covertly and not get involved in a direct confrontation with the United States (known as a “hot war”). The Korean War was a perfect way to do this by simply supporting local North Korean, as well as Chinese, troops. If North Korea successfully took over South Korea, this would increase the USSR’s influence in Asia. |
China | Buffer zoneChina’s leader, Mao Zedong, was alarmed by the proximity of UN forces to his border and even feared an American invasion. Mao wanted North Korea to act as a buffer zone for China, and for this, had to help North Korea remain a communist country. Sino-Soviet TreatyThe Sino-Soviet Treaty of Friendship, Alliance, and Mutual Assistance with the USSR meant that Mao was under pressure from Stalin to help North Korea. |
Military action during the Korean War
From the end of the Second World War, until 25 June 1950, when war broke out, the dividing line between North Korea and South Korea had been the 38th parallel. The maps below show the division of Korea before and after the Korean War. So, what happened during three years of fighting for the end result to be so similar to the start?
The course of the Korean War
Let’s study briefly the course of the war.
Step 1: North push into the South
Between June and September 1950, the North Korean People’s Army (NKPA) invaded South Korea swiftly and pushed the Southern forces all the way to Pusan. During this time, the US sent troops to support South Korea, aided by the United Nations Security Council, which also agreed to send military support.
Fig. 4 - Flag of the Supreme Commander of the Korean People's Army
Step 2: UN Offensive into the North
By September 1950, UN forces led by General MacArthur were ready to launch a counterattack on North Korea. They surprised the NKPA by launching an amphibious invasion at Inchon on 15 September 1950, quickly pushing the North Koreans back over the 38th parallel. By November, they had almost pressed the communists to the Chinese border, along the Yalu River.
Step 3: Entry of China
On 27 November 1950, China decided to invade Korea since it did not want a US-backed state right on its border and it became increasingly concerned about an attack on their country. Around 200,000 Chinese troops joined 150,000 North Korean troops and by the end of 1950, the UN forces were driven back below the 38th parallel.
Step 4: Stalemate
By early 1951, there were over 400,000 Chinese troops in Korea; it was difficult to keep this number of troops equipped with supplies. This factor combined with the extensive bombing of the North by UN forces to the detriment of the North. On the other hand, UN forces were threatened by widespread guerilla activity.
The war came to a stalemate. The Chinese led many offensives trying to break through, one of the most notable being the Chinese Spring Offensive. This operation mobilised more than 700,000 men from the PLA during the summer of 1951 and aimed at permanently driving the UN forces off the Korean peninsula. Although initially successful, the Chinese were halted by 20 May. The US Army then counterattacked the exhausted Chinese forces, inflicting heavy losses, but managed to hold firm near the 38th Parallel.
The stalemate continued, as did the heavy bombing and fighting.
The firing of General MacArthur
MacArthur wanted to use atomic bombs against China to reduce Chinese aid to North Korea. This caused tension between him and President Truman. MacArthur wanted to push further North and expand the conflict to liberate North Korea from communism in keeping with the idea of rollback - converting communist nations to capitalism. Truman on the other hand wanted to act on the policy of containment and prevent communism from spreading into South Korea.
Fig. 5 - President Truman
MacArthur's repeated pleas to use atomic bombs against China and expansion of the conflict led Truman to fire the general on 11 April 1951, who was replaced by General Matthew Ridgway.
Step 5: Peace talks
Peace talks began in July 1951 but soon broke down. In November 1952, newly elected but not yet integrated president, Dwight Eisenhower went to Korea in a bid to end the war. In July 1953, an armistice was finally signed between North Korea, China, and the USA.
Did you know?
For two years, the war was fought in the skies, between American and Soviet pilots! The Soviet pilots were dressed in Chinese uniforms and flew planes with Chinese markings. Technically, the US and USSR were engaging in direct conflict, which could lead to a declaration of war. For this reason, the aerial battles were kept secret from the US population, in case they demanded an all-out war with the USSR.
Comparative roles of China and the USSR
| Chinese actions | Soviet actions |
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Panmunjom Armistice
The Korean War formally ended on 27 July 1953, when an armistice was signed at Panmunjom on the 38th parallel. The Panmunjom Armistice was the conclusion of the longest negotiated armistice in history: it lasted over two years and took 158 meetings to achieve.
Armistice
A formal agreement made by groups or countries at war to stop fighting.
The Korean Armistice Agreement is unique since it is purely a military document. Since there has never been a peace treaty, North Korea and South Korea are still at war to this day as we mentioned earlier!
The armistice did, however, allow for all military forces and equipment to withdraw in order to create a 4km wide Demilitarized Zone. It also prevented both countries from entering the air, ground, or sea spaces under the control of the other.
Consequences of the Korean War
Let's look at the consequences of the Korean War for all parties involved in the table below.
| Country/group | Consequences |
| Korea |
|
| China |
|
| USSR |
|
| USA |
|
| UN |
|
Korean War casualties
The casualties of the Korean War were huge, and though estimates vary, over four million military and civilian lives were lost. Over half of the people that died in the Korean War were civilians.
Some statistics on military casualties include:
- Around 137,000 South Koreans were killed.
- Around 520,000 North Koreans were killed.
- Around 40,000 UN soldiers were killed.
- Around 116,000 Chinese soldiers were killed.1
These numbers do not include those wounded or missing.
Consequences for the Cold War
The Korean War led to the globalisation of the Cold War, with the superpowers now involved in conflicts in Asia rather than just Europe. The US had proved it was willing to intervene when communism threatened non-communist states globally. As well as globalising, the war also intensified with the increase in military spending.
US military spending
Between 1950 and 1953, the defence budget more than tripled, reaching its peak in 1952 during the war.
- 1950: $13 billion
- 1951: $48 billion
- 1952: $60 billion
- 1953: $47 billion2
The Korean war - Key takeaways
- The Korean War was a major conflict of the Cold War period, between North Korea and South Korea. It reached international proportions when the United Nations and US troops intervened to help the South. The fighting ended in July 1953 with the Panmunjom Armistice, and Korea is still divided to this day into two hostile states.
- The Korean War started in June 1950 when North Korea commenced the invasion of South Korea. The US, following its policy of containment, intervened. This is along the lines of the so-called domino theory: the US feared that if one country fell to communism, then other countries would follow.
- The USSR and China both supported North Korea by supplying soldiers, weapons and medical supplies. However, they eventually distanced themselves as China grew weary of the Soviet Union as an ally. This was called the Sino-Soviet Split.
- The Korean War had repercussions around the world and in Korea. South Korea prospered thanks to capitalism, whilst a ruthless dictatorship was installed in North Korea and the majority live in poverty, even today. The US, following the end of the war, set up alliances in Asia to strengthen its grasp on the region.
References
1. L. Yoon, ‘Number of military casualties during the Korean War 1950-1953’, Statista (2021).
https://www.statista.com/statistics/1131592/korean-war-military-casualties/.
2. Samuel Wells, ‘Korea and the Fear of World War III’, Wilson Center (2020). https://www.wilsoncenter.org/blog-post/korea-and-fear-world-war-iii.
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Frequently Asked Questions about The Korean war
When was the Korean war?
The Korean War started on 25 June 1950, when North Korea invaded South Korea, and ended on the 27 July 1953 when the Panmunjom Armistice was signed.
Who won the Korean War?
No country officially won the Korean War. After three years of bloody conflict, the countries involved - the US, China, North Korea and South Korea - agreed to an armistice, which ended all hostilities.
However, if we take into account each country’s goals, then it is clear that the US won the war since it was successful in stopping communism from spreading to South Korea.
How many people died in the Korean war?
Over four million people died during the Korean War. Of these, more than half were civilian casualties.
What was the Korean War?
The Korean War was the first major conflict of the Cold War, fought between North Korea and South Korea. It reached international proportions in June 1950 when the United Nations and US troops intervened to help the South. The fighting ended in July 1953 with the Panmunjom Armistice. Korea is still divided to this day into two hostile states.
What caused the Korean war?
Historians agree that several issues caused the Korean War. These included the spread of communism during the Cold War, America’s policy of containment, and the Japanese occupation of Korea.
In fact, because Japan occupied the Korean Peninsula between 1910 and 1945, the US and USSR had to liberate the region during WWII. The Soviet Union invaded the northern half of Korea whilst the United States liberated the southern half. As the two sides could not agree on uniting the country, it was split into two halves along the 38th parallel. This created tensions between North and South Korea as each side promoted very different ideologies, which ultimately led to North Korea invading South Korea. This in turn led to the outbreak of war. America intervened soon afterwards by sending troops to support the South in a bid to prevent the spread of communism.
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