Edexcel IGCSE History: A World Divided, Superpower Relations, 1943–72 — Revision Notes

Quick-recall notes for Depth Study 6 of Pearson Edexcel International GCSE History 4HI1 Paper 1, “A world divided: superpower relations, 1943–72”. Full explanations are in the superpower relations study guide; practise with the superpower relations practice questions.

Syllabus coverage (4HI1, Depth Study 6)

Key topic	Core content
1. Reasons for the Cold War	Ideology, wartime tension, Tehran, Yalta, Potsdam, Eastern Europe, Truman and Stalin
2. Early developments, 1945–49	Iron curtain, Truman Doctrine, Marshall Plan, Cominform, Comecon, Bizonia, Berlin Crisis, NATO, FRG/GDR
3. The 1950s	Korea, Warsaw Pact, peaceful co-existence, Hungary, arms race
4. Three crises	U2 and Paris Summit, Berlin Wall, Bay of Pigs, Cuban Missile Crisis, Czechoslovakia, Brezhnev Doctrine
5. Thaw and détente, 1963–72	Hotline, Test Ban, Outer Space, NPT, SALT I

The three conferences compared

	Tehran (Nov–Dec 1943)	Yalta (Feb 1945)	Potsdam (July–Aug 1945)
Leaders	Churchill, Roosevelt, Stalin	Churchill, Roosevelt, Stalin	Churchill then Attlee, Truman, Stalin
Agreed	Second front in France; Poland’s borders move west	Four zones of Germany and Berlin; free elections; UN; USSR to fight Japan	Germany demilitarised; zones confirmed; war-crimes trials
Disagreed	Little in public	Poland’s government	Reparations; Poland; Soviet control of Eastern Europe
Mood	Cooperative	Cooperative but wary	Suspicious; atomic bomb revealed

Timeline

Date	Event
Mar 1946	Churchill’s “iron curtain” speech at Fulton
Jan 1947	Bizonia created
Mar 1947	Truman Doctrine
June 1947	Marshall Plan announced
Sept 1947	Cominform set up
Feb 1948	Communist coup in Czechoslovakia
June 1948	Berlin Blockade begins; airlift
Jan 1949	Comecon set up
Apr 1949	NATO formed
May 1949	Blockade lifted
1949	FRG and GDR created; Soviet atomic bomb
1950–53	Korean War
May 1955	Warsaw Pact
Feb 1956	Khrushchev’s Secret Speech
Oct–Nov 1956	Hungarian Rising crushed
Oct 1957	Sputnik
May 1960	U2 shot down; Paris Summit collapses
Apr 1961	Bay of Pigs
Aug 1961	Berlin Wall built
Oct 1962	Cuban Missile Crisis
1963	Hotline; Partial Test Ban Treaty
1967	Outer Space Treaty
1968	Nuclear Non-proliferation Treaty; Prague Spring crushed (Aug); Brezhnev Doctrine
1969	SALT talks begin
May 1972	SALT I signed

Key terms

Term	Meaning
Containment	US policy of stopping communism spreading further
Satellite state	Country under Soviet control in Eastern Europe
Salami tactics	Removing opponents slice by slice to take power
Marshall Aid	US economic aid to rebuild Europe
Cominform / Comecon	Soviet bodies coordinating communist parties / economies
Peaceful co-existence	Khrushchev’s idea of competing without war
De-Stalinisation	Rejecting Stalin’s cult and terror after 1956
Brinkmanship	Pushing a crisis to the edge of war to force the other side back
Brezhnev Doctrine	Bloc right to intervene to protect socialism
Détente	Easing of tension
SALT	Strategic Arms Limitation Talks

Crisis summaries: cause → events → outcome

• Berlin 1948–49: new Western currency → blockade → airlift → blockade lifted; NATO; two Germanys.
• Hungary 1956: de-Stalinisation and Nagy’s reforms → Warsaw Pact withdrawal announced → Soviet invasion → Kádár installed; West does not act.
• Berlin 1961: refugee drain → Wall built → flow stopped; division symbolised.
• Cuba 1962: Bay of Pigs, Soviet missiles → quarantine and negotiation → missiles removed; Hotline and Test Ban follow.
• Czechoslovakia 1968: Prague Spring → invasion → Brezhnev Doctrine; Western protests only.

Worked example: two effects

Explain two effects of the Berlin Crisis of 1948–49.

1. The creation of NATO (1949): the blockade convinced Western states that they needed a permanent military alliance, committing the USA to defending Western Europe.
2. The division of Germany: the FRG and GDR were set up in 1949, making the partition of Germany formal and turning Berlin into a long-term flashpoint.

Common mistakes and exam traps

• Mixing up Yalta and Potsdam. Yalta = cooperation with Roosevelt; Potsdam = suspicion with Truman and the atomic bomb.
• Calling the Marshall Plan military aid. It was economic aid; the Truman Doctrine was the political commitment.
• Saying the West helped Hungary. It condemned the invasion but did not intervene.
• Over-stating SALT I. It limited future growth; it did not cut existing weapons.
• Ending too late. The depth study ends in 1972; Afghanistan and Reagan are outside it.

Frequently asked questions

Why did Stalin want control of Eastern Europe? As a buffer zone after two German invasions, and to spread communism.

What made the Cuban Missile Crisis end peacefully? Kennedy chose a quarantine over air strikes, and both leaders compromised — including the secret deal on US missiles in Turkey.

What did détente achieve by 1972? Treaties limiting testing, space weapons, proliferation and strategic missiles — but no end to rivalry.

Source

Pearson Edexcel International GCSE History (4HI1) specification, Issue 5, February 2026, Paper 1, Depth Study 6.