US Containment of Communism: Revision Notes

Key question 2.5 in Cambridge IGCSE 0470 and O Level 2147 is answered through three case studies only: Korea 1950–53, Cuba 1959–62 and Vietnam 1955–75. For each, learn the American reaction, the key events and a verdict on how well containment worked. The full account is in the containment study guide.

Key terms

Term	Meaning
Containment	Stopping communism spreading to new countries (Truman Doctrine, 1947)
Domino theory	If one state fell to communism, its neighbours would follow (Eisenhower, 1954)
38th parallel	Line dividing North and South Korea
17th parallel	Line dividing North and South Vietnam under the Geneva Accords (1954)
Quarantine	Kennedy’s naval blockade of Cuba, October 1962
Vietnamisation	Nixon’s policy of handing the fighting to South Vietnam’s army

Korea, 1950–53

Date	Event
25 June 1950	North Korea invades the South
June 1950	UN Security Council (USSR absent) backs military help for South Korea
September 1950	Inchon landings; UN forces push north past the 38th parallel
Oct–Nov 1950	China enters the war; UN forces driven back
April 1951	Truman dismisses MacArthur
27 July 1953	Armistice at Panmunjom; border near the 38th parallel

Verdict: containment achieved — South Korea saved — but not “rollback”, since Korea stayed divided.

Cuba, 1959–62

Date	Event
January 1959	Castro overthrows Batista
1960	Nationalisation of US property; US trade embargo begins
January 1961	USA breaks off diplomatic relations
April 1961	Bay of Pigs invasion fails
14 October 1962	U-2 photographs missile sites
22 October 1962	Kennedy announces quarantine
27 October 1962	U-2 shot down over Cuba
28 October 1962	Khrushchev agrees to remove the missiles
1963	Hotline; Partial Test Ban Treaty

Deal: missiles out; US pledge not to invade Cuba; secret removal of US Jupiter missiles from Turkey.

Verdict: mixed — Cuba stayed communist, but Soviet missiles were removed without war.

Vietnam, 1955–75

• Why involved: domino theory; support for Diem after the Geneva Accords; elections of 1956 not held.
• Escalation: advisers (about 16,000 by 1963) → Gulf of Tonkin (August 1964) → Rolling Thunder bombing and combat troops (March 1965) → over 500,000 troops by 1968.
• US tactics: bombing, search and destroy, napalm, Agent Orange, strategic hamlets.
• Viet Cong tactics: guerrilla war, tunnels, Ho Chi Minh Trail, support from the North, China and the USSR.
• Why withdrew: Tet Offensive (January 1968); My Lai (1968); anti-war movement and casualties; Nixon’s Vietnamisation; Paris Peace Accords (January 1973).
• End: Saigon falls, 30 April 1975.

Verdict: failure — Vietnam, Laos and Cambodia all communist by the end of 1975; about 58,000 US dead.

Comparing the three

The cases get harder for the USA: in Korea it fought a conventional war with UN backing; in Cuba it faced a popular revolution 90 miles from Florida, which it could not reverse; in Vietnam it fought a guerrilla war for an unpopular ally. Use this pattern to build a conclusion.

Key dates to learn

Date	Event
March 1947	Truman Doctrine: US support for “free peoples” resisting communism
25 June 1950	North Korea invades South Korea
September 1950	Inchon landings under MacArthur
October–November 1950	Chinese forces enter the war
April 1951	Truman dismisses MacArthur
27 July 1953	Armistice at Panmunjom; border near the 38th parallel
January 1959	Castro takes power in Cuba
April 1961	Bay of Pigs invasion fails
October 1962	Cuban Missile Crisis (13 days)
August 1964	Gulf of Tonkin incident and resolution
January 1968	Tet Offensive
January 1973	Paris Peace Accords; US forces withdraw
30 April 1975	Fall of Saigon

Learning these dates lets you frame each case study precisely, which is what moves a (c) answer from general narrative to a supported judgement.

How to judge “effectively”

Use the same three tests for each case study, then compare:

1. Was communism stopped from spreading there? Korea: yes, South Korea survived; Cuba: no, Castro stayed in power; Vietnam: no, the whole country was united under communist rule in 1975.
2. At what cost? Lives, money and US prestige, for example the long war in Vietnam and the anti-war movement at home.
3. Did it achieve wider aims? For example, the removal of Soviet missiles from Cuba in 1962, even though Castro’s regime survived.

Exam traps

• Bringing in the Berlin Blockade or Marshall Plan as case studies — they belong to key question 2.4.
• Saying the USA “won” the Korean War: it ended in an armistice, not a peace treaty.
• Forgetting the secret Turkey deal when judging the Missile Crisis.
• Describing Vietnam tactics without linking them to why the USA failed.

Frequently asked questions

Why was the USSR not able to veto UN action in Korea? It was boycotting the Security Council in 1950 in protest at Nationalist China, not Communist China, holding China’s seat.

What was the Bay of Pigs? A failed invasion of Cuba in April 1961 by about 1,400 CIA-trained Cuban exiles, approved by Kennedy.

When did the Vietnam War end? US combat forces left after the Paris Peace Accords of January 1973; the war ended when Saigon fell to North Vietnam on 30 April 1975.

Self-test

1. What triggered the Korean War?
2. Why did China join the war in late 1950?
3. What three things were agreed to end the Missile Crisis?
4. Give two reasons why the USA withdrew from Vietnam.
5. Which case study shows containment working best? Why?

Answers: 1. North Korea’s invasion of the South on 25 June 1950. 2. UN forces crossed the 38th parallel and advanced towards the Yalu River on China’s border. 3. Soviet missiles removed; US promise not to invade Cuba; US missiles secretly removed from Turkey. 4. Any two: the Tet Offensive; rising casualties and the anti-war movement; My Lai; Nixon’s Vietnamisation; the cost of the war. 5. Usually Korea, because South Korea stayed non-communist.

Practise next: containment practice questions.