Cpl. Sam Ayala, U.S. 3rd Infantry Division, waits for medical evacuation from Hill 717 during the Korean War. More than 30,000 Americans died in the proxy conflict of the Cold War, in which the U.S. supported South Korea and the Soviet Union and China supported North Korea.

Photograph courtesy U.S. Army Signal Corps

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  • On June 27, 1950, the United States officially entered the Korean War. The U.S. supported the Republic of Korea (commonly called South Korea), in repelling an invasion from the Democratic Republic of Korea (commonly called North Korea).
    The Korean War was a conflict that emerged after World War II. The Empire of Japan had occupied the Korean Peninsula during the war. After Japan’s defeat, the victorious Allies split the peninsula on the 38th parallel. U.S. troops occupied the southern part, while Soviet troops occupied the northern part. The two Koreas engaged in border conflict, which escalated when North Korea invaded South Korea on June 25. 
    The Korean War was a proxy war for the Cold War. The West—the United Kingdom and the U.S., supported by the United Nations—supported South Korea, while communist China and the Soviet Union supported North Korea. The Korean War ended three years later, with more than 600,000 casualties (about 36,000 Americans). The war ended with virtually no change in the border.
    The Korean Peninsula is still divided, with military personnel from both North and South Korea occupying the demilitarized zone (DMZ).
  • Term Part of Speech Definition Encyclopedic Entry
    Allies Noun

    alliance of countries that opposed the Axis during World War II. The Allies were led by the U.S., the United Kingdom, and the Soviet Union.

    border Noun

    natural or artificial line separating two pieces of land.

    Encyclopedic Entry: border
    Cold War Noun

    (1947-1991) conflict between the Soviet Union (and its allies) and the United States (and its allies). The two sides never confronted each other directly.

    communist Noun

    person or group of people who support communism, a type of economy where all property, including land, factories and companies, is held by the government.

    conflict Noun

    a disagreement or fight, usually over ideas or procedures.

    defeat Verb

    to overcome an enemy or obstacle.

    demilitarized zone (DMZ) Noun

    area not controlled by any government, and where it is illegal to station troops.

    emerge Verb

    to develop or come into view.

    empire Noun

    group of nations, territories or other groups of people controlled by a single, more powerful authority.

    escalate Verb

    to increase.

    invasion Noun

    an attack or move to take possession.

    military Noun

    armed forces.

    occupy Verb

    to take control of a place, usually by force.

    parallel Noun

    line of latitude, dividing the Earth by east-west.

    peninsula Noun

    piece of land jutting into a body of water.

    Encyclopedic Entry: peninsula
    proxy war Noun

    conflict where countries indirectly oppose each other by supporting different sides in another conflict.

    repel Verb

    to resist or push back.

    Soviet Adjective

    having to do with the Soviet Union and the areas it influenced.

    support Verb

    to provide emotional, intellectual, or material encouragement or approval.

    troop Noun

    a soldier.

    United Nations Noun

    international organization that works for peace, security and cooperation.

    victorious Adjective

    having won.

    virtually Adverb

    almost or nearly.

    West Noun

    having to do with the developed nations of Europe and North America.

    World War II Noun

    (1939-1945) armed conflict between the Allies (represented by the United States, the United Kingdom, and the Soviet Union) and the Axis (represented by Germany, Italy, and Japan.)