Why were there Cold War proxy wars in Korea and Vietnam?

The logic of proxy wars in a nuclear world

A proxy war takes place when major powers instigate or support combat between other nations or factions instead of fighting one another directly. Following the Soviet Union's first successful atomic bomb test in August 1949, both Washington and Moscow recognized that a direct conflict would escalate to catastrophic nuclear exchanges under the doctrine of deterrence. Consequently, cold war proxy wars in Korea and Vietnam became the primary testing grounds for global hegemony.

Both superpowers operated under distinct strategic assumptions. American policymakers adhered to containment and the domino theory, which claimed that if one country fell to communism, surrounding nations would rapidly follow. Meanwhile, the Soviet Union and the People's Republic of China saw regional liberation struggles as opportunities to expand socialist influence and dismantle Western capitalist hegemony.

The Korean War: containment and stalemate (1950–1953)

The Korean Peninsula was divided along the 38th parallel in 1945 between a Soviet-backed communist North led by Kim Il Sung and an American-backed capitalist South led by Syngman Rhee. On June 25, 1950, North Korean forces invaded South Korea with Soviet material support. The United States quickly organized a United Nations coalition force led by General Douglas MacArthur to repel the invasion.

By October 1950, UN forces pushed deep into North Korea toward the Yalu River, provoking the direct intervention of hundreds of thousands of Chinese troops. The war settled into a grueling war of attrition near the original border. On July 27, 1953, the warring parties signed an armistice creating the Demilitarized Zone (DMZ). No formal peace treaty was ever signed, leaving the peninsula divided into the twenty-first century.

The Vietnam War and contested memories (1954–1975)

Following the defeat of French colonial forces in 1954, the Geneva Accords temporarily partitioned Vietnam at the 17th parallel. Fearing a communist electoral victory, the United States supported the Republic of Vietnam in the South against the communist Democratic Republic of Vietnam in the North and the southern Viet Cong guerrillas. Direct American military commitment grew from advisors in the late 1950s to over 500,000 combat troops by 1968.

Despite massive aerial bombing and superior conventional firepower, the United States faced intractable asymmetric guerrilla warfare, mounting domestic protests, and high casualty numbers. The Paris Peace Accords of January 1973 led to the final withdrawal of American combat units, and on April 30, 1975, communist forces captured Saigon, reunifying the nation under communist rule.

The war is remembered through starkly different lenses. In the United States, it is widely referred to as the Vietnam War, marked by political division, disillusionment with government authority, and collective trauma over veteran reintegration. In Vietnam, it is officially commemorated as the Resistance War Against America for National Salvation (Kháng chiến chống Mỹ cứu nước), celebrated as a decisive struggle against foreign imperial control that finalized the country's national independence.