Key topic 1 · Reasons for the Cold War

What a Grade 9 answer knows here. 'Who caused the Cold War' is the specification question, and the strongest answers do not pick a country — they pick a MECHANISM. Each side took defensive steps that were unambiguously threatening when read from the other side, and no step required bad faith to be alarming.

Every lesson here ends the same way: learn it, teach it to an AI pupil who asks the awkward question, then defend it against the thinker with the strongest claim on it — free · no account needed.

3 lessons, each answering one essential question with the story, the dates that earn marks, the people to place, how historians disagree and the cap in the mark scheme that bites. Completely free.

The 3 lessons

Long-term rivalry and ideological difference

How much of Soviet suspicion of the West in 1945 was ideology, and how much was memory? Capitalism as the USA understood it meant private ownership, competitive markets, multi-party elections, a free press and the right to trade.

Examined through causation and continuity. Learn long-term rivalry and ideological difference →

Tehran, Yalta and Potsdam

What changed between February and July 1945 — Soviet behaviour, or the people in the room? The first meeting of the three leaders.

Examined through change and difference. Learn Tehran, Yalta and Potsdam →

The attitudes of Truman and Stalin

Can two governments produce a Cold War without either of them intending one? Truman became President on 12 April 1945 having been Vice-President for eighty-two days, excluded from Yalta, and unaware of the Manhattan Project until Stimson briefed him within a fortnight.

Examined through causation and difference. Learn the attitudes of Truman and Stalin →

The dates that earn marks in this key topic

Two from each lesson, in the order the topic is taught — each with the reason it is worth a mark, and the lesson that places it.

1918–20 — Allied intervention in the Russian Civil War.: Soviet suspicion of the West has a factual basis a quarter of a century older than the Cold War. (Long-term rivalry and ideological difference)
1933 — The USA finally recognises the USSR, sixteen years after the revolution.: The length of the non-recognition is a measure of how abnormal the relationship was before the alliance. (Long-term rivalry and ideological difference)
November 1943 — Tehran: second front agreed for 1944; Polish borders discussed in outline.: The cooperative conference, and the baseline against which the others are compared. (Tehran, Yalta and Potsdam)
February 1945 — Yalta: zones, the UN, free elections promised, Poland's borders moved west.: Agreed while the Red Army held Poland, which is the fact that governs what the promises were worth. (Tehran, Yalta and Potsdam)
12 April 1945 — Truman becomes President, with no briefing on Yalta or the bomb.: The change of personnel is one of the causes and is precisely datable. (The attitudes of Truman and Stalin)
April 1945 — Truman's blunt first meeting with Molotov.: A concrete instance of the change of tone, quotable in a clause. (The attitudes of Truman and Stalin)

The people to place

Vladimir Lenin — Repudiated tsarist debts and founded the Comintern in 1919 to promote revolution abroad. (Long-term rivalry and ideological difference)
Winston Churchill — Advocated intervention against the Bolsheviks in 1919 and allied with them in 1941, and said so openly. (Long-term rivalry and ideological difference)
Vyacheslav Molotov — Soviet foreign minister; signed the Pact in 1939 and negotiated the post-war settlement. (Long-term rivalry and ideological difference)
Franklin Roosevelt — At Tehran and Yalta; believed a personal relationship with Stalin was the route to a post-war settlement; died April 1945. (Tehran, Yalta and Potsdam)
Harry Truman — At Potsdam; no experience of the wartime alliance and possession of a tested atomic weapon. (Tehran, Yalta and Potsdam)
Clement Attlee — Replaced Churchill at Potsdam after the British election result was announced mid-conference. (Tehran, Yalta and Potsdam)
Joseph Stalin — At all three; his position strengthened by the Red Army's advance and unchanged in its aims. (Tehran, Yalta and Potsdam)
Mátyás Rákosi — Hungarian communist leader who described the technique of eliminating rivals as salami tactics. (The attitudes of Truman and Stalin)

What students say — and what is actually the case

“The Cold War began in 1945.” — Hostility dates from 1917 and the alliance of 1941–45 is the exception in the relationship. Which date you choose depends on your criterion, and the strongest answers say so. (Long-term rivalry and ideological difference)
“Yalta gave Eastern Europe to Stalin.” — Yalta promised free elections in liberated Europe. The Red Army already occupied the territory, and there was no mechanism to enforce the promise. The West conceded a fact rather than a right. (Tehran, Yalta and Potsdam)
“Stalin planned to conquer Western Europe.” — There is no evidence of such a plan, and the Red Army demobilised substantially after 1945. Soviet policy was to control the buffer, which was quite enough to alarm the West without requiring an invasion plan. (The attitudes of Truman and Stalin)

What the specification asks for

The clauses of 4HI1 this key topic examines, one per lesson. Incandio is aligned to the specification and is not published by Pearson.

“Long-term rivalry between the Soviet Union and the West and the ideological differences between Communism and Capitalism” — Long-term rivalry and ideological difference
“Tensions and disagreements during the Second World War. Key features of the conferences at Tehran, Yalta and Potsdam.” — Tehran, Yalta and Potsdam
“The Soviet Union and Eastern Europe. The attitudes of Truman and Stalin.” — The attitudes of Truman and Stalin

Then teach it, and defend it

Every lesson above ends the same way: you explain the argument to Ember, an AI pupil who asks the awkward question, and defend it in a structured debate marked against published descriptors.

All of A world divided: superpower relations, 1943–72 · Incandio History · The 4HI1 specification