Russo-Japanese War in 1904-1905

  • Japanese established authority over Korean peninsula
  • Koreans fought for independence but the Western blocs did not intervene until the outbreak of war in the Pacific during WWII in 1941
  • Cairo Conference 1943 – Roosevelt, Churchill and Chiang Kai-노다 declared support to remove the Japanese from Korea
  • “three great powers, mindful of the enslavement of the people of Korea, are determined that in due course Korea shall become free and independent.”
  • US & Britain secretly agreed with Soviet Union to remove the Japanese influence from Korea

Potsdam Declaration of July 26

  • Reaffirmed the Cairo Declaration of 1943 to secure Korea’s independence
  • This statement was based on the assumption that the Soviet Union and the US would stay allies
  • Japanese forces in Korea north of 38th parallel would surrender to the USSR and south of parallel to the United States
  • Division was intended to last only until arrangements for granting of Korean independence had been concluded by USSR & US

Moscow Agreement December 27 1945

  • The US & USSR agreed to create a “provisional Korean democratic government with a view to the re-establishment of Korea as an independent state”
  • US, USSR, China and Britain agreed to form a Joint Commission to consult with Korean democratic parties and social organizations – US & USSR had ultimate authority
  • Joint Commission discussions began March 20 1946- but adjourned May 8 without agreement
  • Disagreement between US & USSR in establishing a government that was favourable to their own purpose led to break down in agreements
  • By August 1947 negotiations broke down completely

Korea, US and USSR in the UN

  • Koreans demanded political independence while in the US, the expenses in Korea were heavily opposed
  • However the US was not able to abandon Korea due to the Soviet occupation of the North
  • September 17 1947- George Marshall- Secretary of State- dispatched John Dulles the UN General Assembly to propose United Nations Temporary Commission on Korea (UNTCOK) to supervise election in Korea & proposed polling be held before March 1948
  • Goal: to create an independent state in Korea to relieve the US of the expenses and political issues in Korea without leaving a political vacuum in Korea
  • Soviets opposed this proposition and stated Korea could not establish its own government until foreign troops were withdrawn
  • November 4 1948 – Proposal for UNTCOK was passed in the UN by a vote of 43-0 (with 6 abstentions)
  • “the State Department was simply using the Untied Nations as an arm of that office to further its own policies”
  • The UNTCOK members comprised of Australia, China, El Savador, France, India, the Philippines, Syria and Ukraine (Australia, France, El Savador, and the Philippines all had close ties with the US)
  • Soviet Union & North Korean leaders refused to partake in preliminary discussions regarding Korea’s independence and the establishment of a democratic government. The lack of Soviet cooperation rendered the UNTCOK efforts of unified, independent Korea futile
  • PROBLEM: establishment of an elected regime in South Korea independent from the North would lead to a permanent division at the 38th Parallel, a disruptive international boundary. “The event of threats from North, the UN might be placed in the difficult position to having either actively to support, or else to renounce, all responsibility for the government it had established.”
  • March 1 1948 – UNTCOK announced that elections would be held in South Korea by May 10

Elections in Korea

  • May 10 1948- election was held after violent political campaigns in which 589 people were killed
  • 75% of potential voters in South Korea voted
  • Government of the Republic of Korea established under leadership of Syngman Rhee
  • August 12 –US, China and the Philippines recognized the Korean Government
  • July 14 1949- Canada recognized the South Korean government
  • August 25 1948 – North Korea held its own elections and established People’s Democratic Republic under the leadership of Kim-Il Sung

UN Resolution on Korea

  • December 12 1948 – resolution recommended that occupying powers withdraw “as early as practicable”
  • Established a new United Nations Commission on Korea (UNCOK)
  • UNCOK’s role was to observe the withdrawal of occupation forces and assist with problems of political transition and unification
  • December 1948- Soviets announced that they had withdrawn all their forces from North Korea
  • June 1949 – US forces had also withdrawn from South Korea, with the exception of small group of military advisers

Key Figures


  • President Harry S. Truman
  • Gen. MacArthur (US Commander in Korea)
  • Gen. Ridgway (Replaced MacArthur)
  • John Muccio (US Ambassador to South Korea)
  • Secretary of State Acheson


  • Kim Il-sung (Leader of the PKA)
  • Syngman Rhee (“Elected” leader of the ROK)
  • Peng Teh-haui (Leader of CCP forces)

Political Parties

CCP—Communist Party of China

ROK—Republic of (South) Korea

PK—North Korea

ROKA–South Korean Army

PKA—North Korean Army


June 25, 1950—North Korea invades South Korea, followed by a declaration of War

June 26, 1950—President Truman authorizes General MacArthur to…

1.      Send supplies (ammunition, weapons, etc) to aid South Korea

2.      Evacuate Americans in Korea

3.      Send a survey party to assess how best to help the ROK

4.      (Later in the day) Use Air Force aircraft and Naval ships to attack any KPA military target below the 38th Parallel

June 27, 1950—UN Security Council passes UNSC Resolution 82, condemning the KPA invasion of ROK

-This was passed without being vetoed by the USSR as the USSR was boycotting UN meetings since January, 1950 in protest of the People’s Republic of China not being formally recognized by the UN (ie having a seat)

—UNSC Resolution 83 passed, recommending all UN members to provide military assistance to ROK

June 30, 1950—MacArthur receives the ok from the White House to employ ground troops

July 5, 1950—Battle of Osan

–First military engagement of Korean War

–ROKA attacked the KPA at the city of Osan while the KPA was in pursuit of retreating ROKA forces

–Result was a victory for KPA

July 14-21, 1950—Battle of Taejon

–US forces tried to hold military base in Taejon, but were overwhelmed by the superior numbers of the KPA

–Result was victory for the KPA and the evacuation of Taejon

August, 1950—US Congress approves of $12 billion to be sent to ROK to pay for the military expenses

–KPA had pushed back the ROKA and the USA to the city of Pusan, in the south-eastern corner of Korea.

–KPA had pushed so far south that the UN only controlled 10% of Korea (the Pusan border)

August-September, 1950—Battle of the Pusan Border

-the KPA tried to removed the ROKA and the UN forces from Korea, and tried to through August-September

-The US Air Force destroyed most of the bridges and infrastructure during the day into Pusan, halting the PKA advancement to only night-time operations

-At the same time, the US then destroyed resources (logistics depots, petroleum refineries, harbours and transport hubs) around Pusan to deny PKA access to them

-The KPA was over extended and could not be supplied in the south

-The US then continued pooling soldiers and reinforcements from Japan in the Pusan area until their men outnumbered the PKA

September 15-17, 1950—Battle of Inchon

–Major attack against the PKA staged by the UN forces

–Plan was to have an amphibious landing far from Pusan (at city of Inchon), push the PKA far back north and to recapture the ROK capital of Seoul

–Plan was huge success, remaining PKA soldiers retreated North

September 27, 1950—MacArthur told (secretly) that he could advance past the 38th parallel if there was no Chinese/USSR military stationed or planning to be stationed in PK.

October 1, 1950—KPA pushed north, past 38th parallel, with the ROKA following behind

October 7, 1950—UN forces allowed to follow ROKA into KP

October 19, 1950—ROKA and UN forces capture Pyongyang city, capital of PK

-MacArthur continues to push North, planning to go past the Chinese-Korean border

October 25, 1950—MacArthur CROSSES THE RIVER.

–China enters the war

October 26, 1950—Chinese forces begin major offensive against UN and ROKA forces

November 24, 1950—Chinese delegates arrive at UN to (possibly) begin peace talks

-MacArthur starts offensive to push back the Chinese and have the boys “home by Christmas”

-Europe FURIOUS with MacArthur; Called him reckless and purposely trying to prolong the war

-China leaves UN angry

November 30, 1950—Truman publically pushes to gain UN support for MacArthur attacking China.  He also proposes the use of the A-Bomb

Late November, 1950—UN and ROKA forces pushed back past the 38th parallel;

December, 1950 to January, 1951—UN, ROKA and PKA forces at stalemate

January, February, 1951—MacArthur resumes offensive and pushes back to the 38th parallel (in March).

March, 1951—MacArthur pushes past parallel and demands for unconditional CCP surrender

-Truman FURIOUS; all chances for peace negotiations gone now

April 11, 1951—MacArthur fired. Replaced with Ridgway.

July 10, 1951—Peace talks begin.

July 12, 1951—Peace talks fail.

July, 1951-July 1953—Stalemate.

July 27, 1953—UN Ceasefire create with the borders at the 38th parallel remaining in place.

–Korean Demilitarized Zone established (2.5 miles away from the parallel on both sides)


  • The Korean War is the armed conflict of the Cold War following the Second World War
  • Demonstrated the capacity of the limited war ( first limited war of the Cold War) and showed the militaristic and political power of both the Soviets and the Americans
  • Was a failure to reuniting the Koreans
  • China was able to prevail over the Americans: gave confidence to the Communist states for the Cold War
  • The protocol for following the sphere of influence: both superpowers were able to indirectly influence a war through third-party countries
  • Truman’s Containment policy extended the Cold War to the rest of the world; showed how serious the Americans were at containing communism and its spread
  • First time China and the United States fought together following the Second World War
  • Introduced China’s new military modernization programme: efforts to upgrade the PLA’s array of weapon to meet the technological demands of modern war and attempt to professionalize the PLA’s officer corps through military education, doctrine and training
  • Rearmament: The defense budget of the Americans quadrupled and the Americans emerged as the most powerful military nation in the world
  • Domestically: the Korean War speeded up the racial integration of the armed forces (in turn accelerated the civil rights movement)
  • Jet aircraft entered battle against each other for the first time in history
  • Sino-Soviet relations began to deteriorate: Mao became increasingly suspicious of the Soviet regime and their ‘co-existence’ with the Western Hemisphere
    • Believed Soviets were ‘betraying the aims of Communism’

author avatar
William Anderson (Schoolworkhelper Editorial Team)
William completed his Bachelor of Science and Master of Arts in 2013. He current serves as a lecturer, tutor and freelance writer. In his spare time, he enjoys reading, walking his dog and parasailing. Article last reviewed: 2022 | St. Rosemary Institution © 2010-2024 | Creative Commons 4.0

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