Edexcel IGCSE History: The Vietnam Conflict, 1945–75 — Revision Notes

Quick-recall notes for Historical Investigation A4 of Pearson Edexcel International GCSE History 4HI1 Paper 2, “The Vietnam Conflict, 1945–75”. Full explanations are in the A4 study guide; practise the source questions with the A4 practice questions.

Syllabus coverage (4HI1, Investigation A4)

Key topic	Core content
1. Struggle against France, 1945–54	Vietminh aims, Giap’s tactics, diplomacy, Dien Bien Phu
2. US policy, 1954–64	Geneva, Domino Theory, South Vietnam, Ho and Diem, NLF, Trail, Strategic Hamlets, Diem’s fall, Tonkin
3. Escalation, 1964–68	Johnson, McNamara, Westmoreland, Search and Destroy, Rolling Thunder, TV war, Khe Sanh, Tet, Hue
4. Nixon and Ford, 1969–75	Talks, Cambodia, Laos, China, Kissinger and Le Duc Tho, Vietnamisation, fall of Saigon
5. Civilians and US attitudes	Hearts and Minds, My Lai, Phoenix, defoliation, protest, media, Fulbright Hearings

Timeline

Date	Event
Sept 1945	Ho Chi Minh declares independence
Dec 1946	First Indochina War begins
1949–50	Communist China begins supplying the Vietminh
Mar–May 1954	Dien Bien Phu; French surrender on 7 May
July 1954	Geneva Accords: division at the 17th parallel
1955	Diem becomes president of South Vietnam
1956	Reunification elections not held
Dec 1960	NLF formed
1962	Strategic Hamlet Programme
Nov 1963	Diem overthrown and killed
Aug 1964	Gulf of Tonkin incident and resolution
Mar 1965	Rolling Thunder begins; first US combat troops land
Jan 1968	Khe Sanh besieged; Tet Offensive (30–31 Jan)
Feb 1968	Battle of Hue ends
Mar 1968	My Lai massacre; Johnson will not stand again
1969	Nixon announces Vietnamisation; secret bombing of Cambodia
1970	Invasion of Cambodia; Kent State shootings
1971	Laos incursion; Fulbright Hearings
Feb 1972	Nixon visits China
Jan 1973	Paris Peace Accords
Mar 1973	Last US combat troops leave
30 Apr 1975	Fall of Saigon

US presidents and their policies

President	Policy
Truman	Funded the French war effort
Eisenhower	Domino Theory; backed Diem; advisers
Kennedy	More advisers (about 16,000 by 1963); Strategic Hamlets
Johnson	Tonkin Resolution; Rolling Thunder; ground war
Nixon	Vietnamisation; wider war in Cambodia and Laos; Paris Accords
Ford	No further US intervention; Saigon falls

Tactics compared

US and ARVN	NLF and North Vietnam
Bombing (Rolling Thunder)	Tunnels and underground bases
Search and Destroy, helicopters, body counts	Ambushes, booby traps, hit-and-run
Defoliation, napalm	Supply via the Ho Chi Minh Trail
Strategic Hamlets, Hearts and Minds	Support from villagers; political cadres

Key terms

Term	Meaning
Vietminh	Communist-led independence movement (to 1954)
Domino Theory	Belief that one country falling to communism would cause others to fall
NLF / Viet Cong	Communist-led front fighting the South Vietnamese government
ARVN	Army of the Republic of (South) Vietnam
Search and Destroy	Missions to find and kill enemy units
Body count	Number of enemy dead used to measure progress
Vietnamisation	Handing the fighting to South Vietnam as US troops left
Credibility gap	Gap between official claims and what the public saw

Worked example: describe two features

Describe two features of the Tet Offensive (1968). (6 marks)

1. A surprise, coordinated attack during the Vietnamese New Year truce on more than a hundred towns and cities in the South, including the US embassy in Saigon.
2. Heavy fighting and losses, especially in Hue, which took about a month to recapture; the communists lost many fighters, but the offensive destroyed American belief that the war was nearly won.

Why did the USA fail? Factors to weigh

Factor	Evidence
Guerrilla warfare	Tunnels, ambushes, NLF support among villagers
Supply from the North and allies	Ho Chi Minh Trail; Soviet and Chinese weapons
Weak South Vietnam	Diem’s corruption and persecution of Buddhists; coups after 1963
US tactics	Bombing, defoliation and My Lai turned civilians against the USA
Opinion at home	Tet coverage, protest, Kent State, the credibility gap
Political limits	Congress refused more aid in 1975

Common mistakes and exam traps

• Assuming the USA fought France. It funded France’s war; it fought the North and NLF later.
• Calling Tet a communist military victory. It was a military defeat but a political success.
• Ignoring South Vietnam’s weaknesses. Diem’s unpopularity matters to every explanation of US failure.
• Treating media sources as neutral. TV coverage was selective; government statements were optimistic. Use provenance in cross-referencing.
• Forgetting 1973–75. The investigation ends with the fall of Saigon, not with US withdrawal.

Frequently asked questions

Why did France lose? Giap’s tactics, Chinese supplies, popular support for the Vietminh and the disaster at Dien Bien Phu.

Why was Diem overthrown? Corruption, nepotism and persecution of Buddhists made him a liability; the USA did not prevent the generals’ coup.

How did the war affect American society? It divided the country, fuelled protest and damaged trust in government.

Source

Pearson Edexcel International GCSE History (4HI1) specification, Issue 5, February 2026, Paper 2, Historical Investigation A4.