The alliance that defeated Nazi Germany broke up within two years. Distrust between the USA and the USSR divided Europe and shaped the next 45 years.
🤝 From allies to rivals
At Yalta (February 1945) and Potsdam (July 1945) the Allies disagreed about Germany and Eastern Europe. The USSR set up friendly communist governments in the countries its army had liberated. In 1946 Churchill spoke of an “iron curtain” dividing Europe. In 1947 the Truman Doctrine pledged US support for countries resisting communism, and the Marshall Plan (1948–1952) offered about $13 billion in aid to rebuild Western Europe. Stalin refused it for the Eastern bloc and created Cominform.
1945 Yalta and Potsdam
1946 Iron Curtain speech
1947 Truman Doctrine
1948 Marshall Plan; Berlin Blockade
🖼️ See it
Each step by one side was read as a threat by the other.
🌉 Berlin and the blocs
The Western zones of Germany merged and introduced a new currency. In response, Stalin blockaded West Berlin (June 1948 – May 1949). The West flew in supplies in the Berlin Airlift. The crisis led to the creation of NATO (1949) and the division of Germany into West and East. The USSR responded with the Warsaw Pact (1955) and tested its first atomic bomb in 1949.
Historians disagree: orthodox views blame Soviet expansion, revisionists stress US economic power, post-revisionists see mutual mistrust.
✏️ Quick check · 1 of 8
Iron curtain
Who spoke of an “iron curtain” in 1946?
A British leader.
✏️ Quick check · 2 of 8
Truman Doctrine
The Truman Doctrine pledged:
Containment.
✏️ Quick check · 3 of 8
Marshall Plan
The Marshall Plan offered:
Aid.
✏️ Quick check · 4 of 8
Berlin
The Berlin Blockade was ended by:
The Airlift.
✏️ Quick check · 5 of 8
NATO
NATO was formed in 1949 as:
Western alliance.
✏️ Quick check · 6 of 8
Interpretations
A revisionist historian would stress:
Challenges blame on USSR.
✍️ Type your answer · 7 of 8
The Berlin Blockade lasted from June 1948 to May 1949.
About how many months did it last?
Enter an exact answer, without rounding.
months
Count the months.
✍️ Type your answer · 8 of 8
NATO was founded in 1949 and the Warsaw Pact in 1955.
How many years later was the Warsaw Pact formed?
Enter an exact answer, without rounding.
years
Subtract the years.
📝 Lesson quiz · 5 questions
0 / 5
Re-read the lesson, then give it another go.
Question 1 of 5
Yalta and Potsdam were:
Question 2 of 5
Containment meant:
Question 3 of 5
The USSR tested its first atomic bomb in:
Question 4 of 5
Which organisation did the USSR form in 1955?
Question 5 of 5
The Berlin Airlift supplied:
Lesson 2 · International history
☢️ Crises & Détente, 1950–1979
The Cold War turned hot in Asia and brought the world close to nuclear war in Cuba. Then both sides worked, for a time, to lower tensions.
🔥 Flashpoints
The Korean War (1950–53) saw the US-led UN force and China fight over a divided peninsula. In 1956 Soviet tanks crushed the Hungarian Uprising. The Berlin Wall was built in 1961 to stop East Germans leaving. In the Cuban Missile Crisis (October 1962) the US demanded the removal of Soviet missiles from Cuba, a standoff of 13 days; the USSR withdrew them in return for a US pledge not to invade Cuba and a quiet removal of US missiles from Turkey. A hotline followed in 1963.
1950 Korean War begins
1956 Hungary
1961 Berlin Wall
1962 Cuban Missile Crisis (13 days)
🖼️ See it
Détente (SALT I, Helsinki 1975) lasted until the invasion of Afghanistan.
🕊️ Détente
Détente was a relaxation of tension in the 1970s. Key steps: SALT I (1972), limiting nuclear missiles; Nixon’s visit to China (1972); and the Helsinki Accords (1975), which recognised post-war borders and included commitments to human rights. Détente weakened after the Soviet invasion of Afghanistan in 1979. The Vietnam War (US withdrawal 1973) showed the limits of US power.
Judge: was détente a real change or just a pause caused by economic pressures on both sides?
✏️ Quick check · 1 of 8
Korea
The Korean War began in:
1950.
✏️ Quick check · 2 of 8
Hungary
In 1956 the USSR responded to Hungary’s uprising by:
Force.
✏️ Quick check · 3 of 8
Wall
The Berlin Wall was built to:
Prevent emigration.
✏️ Quick check · 4 of 8
Cuba
The Cuban Missile Crisis ended with:
Compromise.
✏️ Quick check · 5 of 8
Détente
Détente means:
Easing.
✏️ Quick check · 6 of 8
SALT
SALT I was an agreement to:
Arms control.
✍️ Type your answer · 7 of 8
The Cuban Missile Crisis lasted from 16 to 28 October 1962.
About how many days did it last (inclusive)?
Enter an exact answer, without rounding.
days
Count the days.
✍️ Type your answer · 8 of 8
The Berlin Wall was built in 1961 and fell in 1989.
How many years did it stand?
Enter an exact answer, without rounding.
years
Subtract the years.
📝 Lesson quiz · 5 questions
0 / 5
Re-read the lesson, then give it another go.
Question 1 of 5
The Helsinki Accords (1975) included:
Question 2 of 5
The hotline established in 1963 aimed to:
Question 3 of 5
What ended détente in 1979?
Question 4 of 5
Nixon visited China in:
Question 5 of 5
The Vietnam War showed that:
Lesson 3 · International history
🧱 The End of the Cold War, 1979–1991
Within a decade the superpower rivalry that had defined the world collapsed. Historians debate whether pressure from outside or reform within brought the Soviet Union down.
🔄 Gorbachev’s reforms
After the invasion of Afghanistan (1979) and the Reagan arms build-up of the 1980s, the Soviet economy was stretched. Mikhail Gorbachev became leader in 1985 and introduced glasnost (openness) and perestroika (restructuring). He also signed the INF Treaty (1987), eliminating a class of nuclear missiles, and refused to use force to prop up communist governments in Eastern Europe.
The pace of change after 1989 surprised almost everyone.
💥 Collapse
In 1989 communist governments fell across Eastern Europe. The Berlin Wall was opened on 9 November 1989, and Germany reunified in 1990. After an attempted coup in August 1991, the republics left the USSR, and it was dissolved on 26 December 1991. Explanations vary: US pressure and spending, economic failure, nationalism in the republics, or Gorbachev’s decisions.
Weigh the causes: which factor was necessary, and which only sped things up?
✏️ Quick check · 1 of 8
Glasnost
Glasnost meant:
Open.
✏️ Quick check · 2 of 8
Perestroika
Perestroika meant:
Restructuring.
✏️ Quick check · 3 of 8
INF
The INF Treaty (1987) eliminated:
Missiles.
✏️ Quick check · 4 of 8
Eastern Europe
Gorbachev’s decision not to use force in Eastern Europe meant:
No intervention.
✏️ Quick check · 5 of 8
Dissolution
The USSR was dissolved in:
1991.
✏️ Quick check · 6 of 8
Debate
Which argument stresses internal causes of Soviet collapse?
Internal.
✍️ Type your answer · 7 of 8
Gorbachev became Soviet leader in 1985 and the USSR dissolved in 1991.
How many years was he in charge of reform before the end?
Enter an exact answer, without rounding.
years
Subtract the years.
✍️ Type your answer · 8 of 8
The INF Treaty was signed in 1987 and the Berlin Wall fell in 1989.
How many years later did the Wall fall?
Enter an exact answer, without rounding.
years
Subtract the years.
📝 Lesson quiz · 5 questions
0 / 5
Re-read the lesson, then give it another go.
Question 1 of 5
The Berlin Wall was opened on:
Question 2 of 5
Germany was reunified in:
Question 3 of 5
Which event triggered the final dissolution of the USSR?
Question 4 of 5
Reagan’s “Star Wars” programme was:
Question 5 of 5
Eastern European revolutions of 1989 were largely:
Lesson 4 · International history
🌍 Decolonisation
In the three decades after 1945, European empires in Asia and Africa gave way to dozens of independent states.
🚩 Independence movements
The Second World War weakened Britain and France and boosted nationalism. India and Pakistan became independent in 1947. Ghana was the first sub-Saharan colony to win independence, in 1957, under Kwame Nkrumah. In 1960, “the Year of Africa”, 17 African states became independent, and Harold Macmillan spoke of a “wind of change”. Britain often negotiated; France fought a bitter war in Algeria (1954–62), and Portugal held on until the 1970s.
1947 India and Pakistan
1957 Ghana
1960 Year of Africa (17 states)
1962 Algeria
🖼️ See it
Britain often negotiated independence; France fought a long war in Algeria.
⚖️ Causes and consequences
Causes: nationalist movements, economic cost of empire, pressure from the USA and USSR, and UN support for self-determination. Consequences: new states faced poverty, ethnic divisions from colonial borders, and Cold War interference. Many leaders pursued non-alignment (the Bandung Conference 1955, the Non-Aligned Movement 1961).
Evaluate: was decolonisation mainly the result of colonial weakness or of the strength of nationalist movements?
✏️ Quick check · 1 of 8
India
India and Pakistan became independent in:
Post-war.
✏️ Quick check · 2 of 8
Ghana
Ghana’s first leader after independence was:
Pan-Africanist.
✏️ Quick check · 3 of 8
Wind of change
Who spoke of “the wind of change” in Africa?
A British prime minister.
✏️ Quick check · 4 of 8
Algeria
Algerian independence was won after:
War.
✏️ Quick check · 5 of 8
Non-alignment
The Non-Aligned Movement sought to:
Neutral.
✏️ Quick check · 6 of 8
Borders
A common problem for new African states was that:
Artificial borders.
✍️ Type your answer · 7 of 8
India became independent in 1947 and Ghana in 1957.
How many years later did Ghana gain independence?
Enter an exact answer, without rounding.
years
Subtract the years.
✍️ Type your answer · 8 of 8
17 African states became independent in 1960. Africa has 54 states today.
About what percentage of today’s states became independent in that one year? Round to the nearest whole number.
Round your answer as the question asks.
%
Divide, then × 100.
📝 Lesson quiz · 5 questions
0 / 5
Re-read the lesson, then give it another go.
Question 1 of 5
The “Year of Africa” was:
Question 2 of 5
Which colonial power fought a major war to keep Algeria?
Question 3 of 5
The Bandung Conference of 1955 was a meeting of:
Question 4 of 5
Which factor helped decolonisation?
Question 5 of 5
Self-determination means:
Lesson 5 · Skills
🔎 Sources & Historical Interpretations
A-Level history is as much about how we know as what happened. You must test sources and compare how historians interpret the past.
📄 Testing a source
Use provenance: nature (what kind of source), origin (who, when, where) and purpose (why it was made). Then judge utility (useful for what?) and reliability (can it be trusted?). A biased source can still be useful, for example to show attitudes at the time. Cross-reference with other sources and your own knowledge.
Source: a 1950 US propaganda poster
Useful for: US attitudes to communism
Limited for: balanced facts about the Soviet Union
🖼️ See it
Then weigh the sources against your own knowledge to reach a judgement.Post-revisionists add misperception and mutual fear, using evidence from archives opened after 1991.
🗣️ Interpretations
Historiography studies how historians’ views change. For the Cold War, orthodox historians blamed Soviet expansion, revisionists blamed US economic and political ambitions, and post-revisionists stressed misperception and mutual fear. An interpretation is shaped by the historian’s time, access to evidence (such as opened Soviet archives after 1991) and perspective.
Argue with evidence: state which interpretation is more convincing and why, using sources and knowledge.
✏️ Quick check · 1 of 8
Provenance
Provenance includes the source’s:
Where from, who for?
✏️ Quick check · 2 of 8
Utility
A biased source can still be useful because it:
Useful for what?
✏️ Quick check · 3 of 8
Orthodox
The orthodox view of the Cold War blamed:
The USSR.
✏️ Quick check · 4 of 8
Revisionist
Revisionist historians argued that:
Challenged blame.
✏️ Quick check · 5 of 8
Archives
Opened Soviet archives after 1991:
New evidence.
✏️ Quick check · 6 of 8
Cross-reference
Cross-referencing sources means:
Compare.
✍️ Type your answer · 7 of 8
A student finds 8 sources on an event, and 6 agree with a claim.
What percentage agree?
Enter an exact answer, without rounding.
%
Part ÷ whole × 100.
✍️ Type your answer · 8 of 8
A document was written in 1948. A historian first studied it in 2018, after the archive opened.
How many years after it was written was that?
Enter an exact answer, without rounding.
years
Subtract the years.
📝 Lesson quiz · 5 questions
0 / 5
Re-read the lesson, then give it another go.
Question 1 of 5
The purpose of a source affects its:
Question 2 of 5
Which is a primary source?
Question 3 of 5
Historiography is the study of:
Question 4 of 5
A strong evaluation of an interpretation uses:
Question 5 of 5
Hindsight can distort history because:
Final Challenge
🏆 10-Question Challenge Quiz
Questions from every topic in this course. Pick an answer for each one, then hit Check My Answers.
0 / 10
💪 Keep practicing — go back through the lessons and retake the quiz!
Q1 · Origins of the Cold War, 1945–1949
The most important result of the Berlin crisis was:
Q2 · Origins of the Cold War, 1945–1949
The Berlin Airlift supplied:
Q3 · Crises & Détente, 1950–1979
Which best explains the Soviet decision to remove missiles from Cuba?
Q4 · Crises & Détente, 1950–1979
The Vietnam War showed that:
Q5 · The End of the Cold War, 1979–1991
The most balanced explanation for the end of the Cold War is:
Q6 · The End of the Cold War, 1979–1991
Eastern European revolutions of 1989 were largely:
Q7 · Decolonisation
A balanced explanation of decolonisation would stress:
Q8 · Decolonisation
Self-determination means:
Q9 · Sources & Historical Interpretations
When weighing two conflicting interpretations, the best approach is to: