On March 5, 1946, in the small town of Fulton, Missouri, a private citizen rose to speak with the President of the United States seated behind him. Winston Churchill — voted out of office months after winning the war — had no power left but his voice, and he used it to name the new shape of the world:
"From Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the Continent."
The phrase landed like a thunderclap. Less than a year earlier, American, British, and Soviet soldiers had embraced on the banks of the Elbe, allies in the destruction of Hitler. Now Churchill warned that an old ally had become a new menace — that behind his "iron curtain" the ancient capitals of Central and Eastern Europe lay under Moscow's growing control. Joseph Stalin answered within days, calling Churchill "a firebrand of war." The Grand Alliance was dead. This lesson asks how the partners who beat fascism turned on each other, and how their quarrel froze Europe into two hostile halves for forty-four years — a divided continent that would not be made whole until 1989.
The Cold War was the prolonged geopolitical and ideological confrontation between the United States and its allies (the capitalist, liberal-democratic West) and the Soviet Union and its satellites (the communist East), lasting roughly from 1945 to 1991. It was "cold" because the two superpowers never fought each other directly — a "hot" war between nuclear-armed giants was unthinkable — yet it was waged everywhere else: through proxy wars, espionage, propaganda, an arms race, and the partition of a continent.
The alliance that won World War II had always been a marriage of necessity between systems that despised each other. As the war ended, the cracks widened. At the Yalta Conference (February 1945) the "Big Three" — Roosevelt, Churchill, and Stalin — agreed in principle on a postwar order, including a pledge of "free elections" in liberated Eastern Europe. But the Red Army already occupied that region, and Stalin, who had seen his country invaded through Eastern Europe twice in a generation, intended to keep it under Soviet control as a security buffer. By the Potsdam Conference (July–August 1945) — with Roosevelt dead and replaced by Harry Truman, and the atomic bomb now in American hands — the suspicion was open. To Washington, Stalin was breaking his Yalta promise and swallowing Eastern Europe. To Moscow, the West was denying the Soviet Union the secure borders it had bled for. Both sides acted out of a tangled mix of ideology and security fear, and each read the other's defensive moves as aggression — the tragic engine of the Cold War.
Connections (backward): The Cold War is the unfinished business of World War II (Lesson 22). The Red Army's westward sweep against Hitler put Soviet boots in Warsaw, Budapest, and eastern Germany — and where the armies stopped in 1945, the Iron Curtain fell. Geography made by war became the political map of the Cold War.
Churchill's "Sinews of Peace" speech at Fulton (March 1946) gave the division its enduring name — the Iron Curtain — and framed it for Western publics as a struggle of freedom against tyranny. The intellectual architecture of the American response came from the diplomat George F. Kennan. In his "Long Telegram" from Moscow (February 1946) and his anonymous "X" article, "The Sources of Soviet Conduct" (Foreign Affairs, July 1947), Kennan argued that Soviet hostility was rooted in ideology and insecurity and could not be charmed away — but that it could be checked. His prescription became the master strategy of the West: containment — "a long-term, patient but firm and vigilant containment of Russian expansive tendencies." The goal was not to roll communism back by force but to hold the line until the Soviet system mellowed or collapsed from within.
Containment became policy in 1947–1948 through two linked initiatives. The Truman Doctrine (March 1947) pledged American support to "free peoples who are resisting attempted subjugation," with immediate aid to Greece and Turkey, where communist pressure threatened. It committed the United States, for the first time in peacetime, to a global anti-communist mission. Then came the Marshall Plan — formally the European Recovery Program — announced by Secretary of State George C. Marshall at Harvard in June 1947 and funded from 1948. It poured some $13 billion into rebuilding Western Europe's shattered economies, on the logic that prosperous democracies would resist communism while ruined ones might embrace it. Aid was offered to all of Europe, but Stalin forbade the Eastern bloc to accept it, deepening the divide. Together, the doctrine and the plan were the two faces of containment — military-political resolve and economic reconstruction.
Connections (compare): Keep the Truman Doctrine and the Marshall Plan distinct (section e). The Truman Doctrine is a commitment — a statement of strategy and military/political aid against communist takeover. The Marshall Plan is money — large-scale economic reconstruction. One is the spine; the other is the wallet.
Defeated Germany became the front line. The country — and its capital, Berlin, stranded deep inside the Soviet zone — had been split into four occupation zones (American, British, French, Soviet). When the three Western powers moved to merge their zones and introduce a new currency in 1948, Stalin tried to squeeze them out of Berlin. In June 1948 he ordered the Berlin Blockade, cutting all road, rail, and canal access to the city's western sectors and hoping to starve the Allies out. Rather than fight or abandon two million Berliners, the West answered with the Berlin Airlift (1948–49) — flying in food, coal, and supplies around the clock, a plane landing every few minutes at the peak. After eleven months Stalin lifted the blockade in May 1949, a major Soviet humiliation. The crisis sealed Germany's division: in 1949 the western zones became the Federal Republic of Germany (West Germany) and the Soviet zone the German Democratic Republic (East Germany).
The Berlin crisis convinced the West to formalize a military alliance. In April 1949, the United States, Canada, and ten Western European states signed the North Atlantic Treaty, creating NATO — a mutual-defense pact in which an attack on one was an attack on all. It anchored the United States permanently in European defense. When West Germany was admitted to NATO and rearmed in 1955, the Soviet Union responded by binding its satellites into the Warsaw Pact (1955), its own military alliance. Two armed camps now faced each other across the Iron Curtain.
Overshadowing everything was the nuclear arms race. The U.S. atomic monopoly ended when the Soviets tested an atomic bomb in 1949; both sides soon built hydrogen bombs and the missiles to deliver them. By the 1960s the superpowers possessed enough warheads to destroy each other many times over — a balance of terror later nicknamed "mutually assured destruction" (MAD). The logic was grim but stabilizing: precisely because total war meant annihilation, the superpowers avoided direct combat and fought instead at the edges.
Divided Berlin remained the rawest wound. Through the 1950s, East Germans fleeing communism simply walked into West Berlin — some 2.5–3 million of them, often the young and skilled, draining the East. To stop the hemorrhage, the East German regime, with Soviet approval, sealed the border on August 13, 1961, throwing up barbed wire that hardened into the Berlin Wall. Families were split overnight; would-be escapers were shot. The Wall was a propaganda disaster for the East — a state that had to imprison its own people — but it worked, stabilizing East Germany and standing as the Cold War's starkest symbol until 1989.
Connections (forward): The Berlin Wall opens this lesson's spine and closes the next. Built in 1961 to cage a population, it became the icon of the divided continent — and its fall on November 9, 1989 (Lesson 25) will mark the Cold War's effective end in Europe. Watch the Wall as the barometer of the whole era.
The Soviet bloc was never quiet. Twice, satellite peoples tried to loosen Moscow's grip, and twice Soviet tanks answered.
In 1956, the Hungarian Uprising erupted in Budapest. Reform-minded crowds and a new government under Imre Nagy demanded liberalization, free elections, and withdrawal from the Warsaw Pact. Moscow could not tolerate a satellite leaving the bloc: on November 4, 1956, Soviet tanks rolled into Budapest and crushed the revolt, killing thousands. Nagy was later arrested and executed (1958). The West, absorbed in the simultaneous Suez Crisis and unwilling to risk war, offered sympathy but no aid — a bitter lesson that "rollback" was rhetoric and containment the reality.
In 1968, Czechoslovakia tried reform from within the party. Under Alexander Dubček, the Prague Spring loosened censorship and promised "socialism with a human face." Again Moscow saw mortal danger, and on the night of August 20–21, 1968, Warsaw Pact forces invaded and ended the experiment. To justify it, the Soviets proclaimed the Brezhnev Doctrine: the USSR claimed the right to intervene in any socialist country where communist rule was threatened. Sovereignty within the bloc was conditional — limited by Moscow's veto.
The late 1960s and 1970s brought a thaw called détente — a relaxation of tensions through negotiation. The superpowers signed arms-control agreements (the SALT I treaty, 1972), and in the Helsinki Accords (1975) thirty-five nations accepted Europe's postwar borders in exchange for Soviet pledges to respect human rights — pledges that dissidents behind the Curtain would later wield as a weapon against their own governments.
Then came a challenge Moscow could not simply crush. In 1980, strikes at the Lenin Shipyard in Gdańsk, Poland, gave birth to Solidarity (Solidarność) — the first independent, self-governing trade union in the Soviet bloc, led by the electrician Lech Wałęsa and backed by the Catholic Church and the Polish pope, John Paul II. At its height Solidarity claimed nearly 10 million members. The regime imposed martial law (December 1981) and drove the union underground, but it could not kill it. Solidarity proved that an organized society could defy a communist state and survive — a model for the revolutions to come.
Connections (forward): Hold these threads — economic exhaustion from the arms race, the moral leverage of Helsinki's human-rights clauses, and the example of Solidarity. When Mikhail Gorbachev comes to power in 1985 with glasnost and perestroika and renounces the Brezhnev Doctrine, this accumulated bloc discontent will erupt into the largely peaceful revolutions of 1989 and the dissolution of the USSR in 1991 (Lesson 25). The end of the Cold War was made possible by reform at the top meeting pressure from below.
Source: Winston Churchill, "The Sinews of Peace" (the "Iron Curtain Speech"), delivered at Westminster College, Fulton, Missouri, March 5, 1946. [Authentic and extensively documented; wording below matches the standard published text. Verify against the International Churchill Society edition for any quotation used on an exam.]
"From Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the Continent. Behind that line lie all the capitals of the ancient states of Central and Eastern Europe. Warsaw, Berlin, Prague, Vienna, Budapest, Belgrade, Bucharest and Sofia, all these famous cities and the populations around them lie in what I must call the Soviet sphere, and all are subject in one form or another, not only to Soviet influence but to a very high and, in many cases, increasing measure of control from Moscow."
HAPPY analysis: - Historical context: Spoken less than a year after V-E Day, as Soviet-backed governments tightened their hold on Eastern Europe and the wartime alliance dissolved into mutual suspicion. Kennan's "Long Telegram" had reached Washington only days earlier. - Audience: The American public and government (with President Truman seated behind him), and the wider English-speaking world — Churchill was urging the United States not to retreat into isolation but to stand with Britain. - Purpose: To alert the West to what Churchill saw as the Soviet danger and to argue for a firm, united Anglo-American front — a call to resist, not yet a call to war. - Point of view: Churchill was an out-of-office statesman and a lifelong, vehement anti-communist; this is a partisan warning, not a neutral report. He had every reason to dramatize the threat, and the Soviets read it as exactly the hostile provocation he intended to sound the alarm about. - whY it matters: The speech crystallized the idea of a divided Europe and gave the era its defining metaphor. It marks, for many historians, the rhetorical opening of the Cold War — and its phrasing shaped how a generation of Westerners understood the conflict.
Who or what "caused" the Cold War? Historians have argued this for decades, and the AP exam rewards an even-handed, evidence-based answer rather than a verdict. - The traditionalist (orthodox) view, dominant in the early decades, blamed Soviet expansionism: Stalin broke the Yalta promise of free elections, imposed puppet regimes across Eastern Europe, and pursued ideological aggression; the West merely reacted defensively through containment. - The revisionist view, rising in the 1960s, emphasized American responsibility: U.S. economic ambitions, the atomic monopoly, and an aggressive containment policy (the Truman Doctrine, the Marshall Plan as a tool of capitalist influence) provoked a Soviet Union whose aims in Eastern Europe were essentially defensive — a buffer against a third invasion from the west. - The later post-revisionist synthesis holds that neither side simply "started" it: the Cold War emerged from a security dilemma in which two suspicious superpowers with incompatible systems each read the other's defensive measures as aggression, so that the spiral escalated even without a single villain.
A balanced answer recognizes that ideology, security fears, misperception, and the power vacuum left by World War II all contributed.
Compare Hungary 1956 and Czechoslovakia 1968. Both were attempts to loosen Soviet control that ended under Soviet tanks — but they differed in kind. Hungary (1956) was a popular, anti-Soviet uprising that went furthest of all: Nagy declared neutrality and announced withdrawal from the Warsaw Pact, a direct break with the bloc. Prague Spring (1968) was a reform movement from within the Communist Party: Dubček sought to humanize socialism, not to leave the alliance. Moscow crushed both, but the 1968 invasion produced the explicit Brezhnev Doctrine, codifying the principle — implicit since 1956 — that no satellite would be permitted to escape the Soviet orbit.
Truman Doctrine vs. Marshall Plan. Both are 1947 American responses to the Soviet threat, and students mix them up. The Truman Doctrine (March 1947) is a policy commitment — a pledge to support "free peoples" resisting communism, with immediate aid to Greece and Turkey. The Marshall Plan (announced June 1947, funded 1948) is economic reconstruction — roughly $13 billion to rebuild Western Europe. Doctrine = strategy and resolve; Plan = money and recovery.
Berlin Blockade/Airlift (1948–49) vs. Berlin Wall (1961). Two different Berlin crises, thirteen years apart. The Blockade/Airlift (1948–49) was Stalin cutting off West Berlin and the West flying supplies in — a contest over access. The Berlin Wall (1961) was East Germany sealing its border to stop its citizens from fleeing. If the stimulus shows cargo planes, it's 1948–49; if it shows concrete and barbed wire dividing the city, it's 1961.
Hungary 1956 vs. Prague Spring 1968. Both crushed by Soviet-led force, but Hungary was a popular uprising under Nagy that tried to leave the Warsaw Pact; Prague was a party-led reform under Dubček ("socialism with a human face") that stayed within the bloc. The 1968 invasion produced the Brezhnev Doctrine.
NATO vs. the Warsaw Pact. NATO (1949) is the Western, U.S.-led alliance; the Warsaw Pact (1955) is the Eastern, Soviet-led alliance formed in response — and six years later. Don't reverse them, and remember NATO came first.
Stimulus for Questions 13–14. Read the excerpt.
"I believe that it must be the policy of the United States to support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures." — Address by President Harry S. Truman to a joint session of Congress, March 12, 1947 [authentic; standard published wording — verify exact text]
Stimulus for Questions 15–16. Study the simplified map description of Cold War Europe, c. 1955.
NATO / WEST | IRON CURTAIN | WARSAW PACT / EAST
-------------------------------- | ============== | --------------------------------
Britain · France · West Germany | | East Germany · Poland
Italy · Belgium · Netherlands | <-- Stettin | Czechoslovakia · Hungary
(U.S. forces stationed in West) | to Trieste --> | Romania · Bulgaria · (USSR)
Neutral: Switzerland · Sweden | | Yugoslavia: communist but NON-aligned
DBQ Partial (Thesis · Grouping · Sourcing) — see section (g). A strong response: states a defensible, two-sided thesis framing the origins as a security dilemma rather than one nation's fault; groups the documents analytically (Western case: Docs 1, 3 / Soviet case: Docs 2, 4 / economic dimension: Doc 5) rather than summarizing them in sequence; and sources at least two documents with genuine HIPP analysis that explains why the author's purpose or point of view matters to the argument (modeled for Docs 3 and 4). For the full DBQ it would add contextualization (the breakdown of the Grand Alliance amid WWII's devastation), at least one piece of outside evidence (e.g., the Berlin Blockade/Airlift, Yalta, or NATO), and a complexity move (weighing traditionalist vs. revisionist interpretations even-handedly). Remember that Document 5 is representative, not authentic, and must not be quoted as a real person's words.
On the real exam, the Document-Based Question (DBQ) gives you seven documents and 60 minutes (including 15 minutes of reading); you must form a thesis, contextualize, use at least four documents as evidence, source at least two (explain how a document's point of view, purpose, historical situation, or audience is relevant — "HIPP"), and add complexity. This partial drill uses five documents and focuses on the three hardest moves: a strong thesis, the grouping of documents, and sourcing (HIPP) for two.
Prompt: Evaluate the extent to which the United States and the Soviet Union were each responsible for the origins of the Cold War in Europe, c. 1945–1949.
Each document is labeled authentic (a real, attributed primary source) or representative (a composite written to stand in for a typical contemporary voice — clearly not a real quotation). Always treat them differently: only authentic documents may be quoted as evidence of what a real person said.
Document 1 — Authentic. Winston Churchill, "The Sinews of Peace," Fulton, Missouri, March 5, 1946.
"From Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the Continent.... all are subject in one form or another, not only to Soviet influence but to a very high and, in many cases, increasing measure of control from Moscow." [standard published wording — verify]
Document 2 — Authentic. Joseph Stalin, interview reply to Churchill's speech, Pravda, March 14, 1946.
"In substance, Mr. Churchill now stands in the position of a firebrand of war.... What can there be surprising in the fact that the Soviet Union, anxious for its future safety, is trying to see to it that governments loyal in their attitude to the Soviet Union should exist in [the bordering] countries?" [authentic; English wording varies by translation — verify against a scholarly edition]
Document 3 — Authentic. President Harry S. Truman, address to Congress (the Truman Doctrine), March 12, 1947.
"I believe that it must be the policy of the United States to support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures." [standard published wording — verify]
Document 4 — Authentic. Nikolai Novikov, Soviet Ambassador to Washington, telegram to Moscow, September 27, 1946 (the Soviet counterpart to Kennan's analysis).
"The foreign policy of the United States... reflects the imperialist tendencies of American monopoly capital, and is characterized... by a striving for world supremacy." [authentic; translation wording varies — verify]
Document 5 — Representative (composite — not a real quotation). A Western European foreign minister, reflecting on the Marshall Plan offer, 1947.
"Our cities are rubble and our people are cold and hungry. American aid is the difference between recovery and collapse — and a hungry, hopeless people is the soil in which communism grows. We take the aid not as charity but as survival." [representative voice illustrating the Western recovery rationale]
Although the Soviet imposition of loyal regimes across Eastern Europe gave Western leaders genuine cause for alarm, the Cold War's origins are best understood not as the work of a single aggressor but as a security dilemma in which both superpowers, driven by clashing ideologies and by real fears for their security, interpreted the other's defensive moves as aggression — so that American containment and Soviet bloc-building escalated each other into a divided Europe by 1949.
This thesis is strong because it takes a defensible, evaluative position ("not the work of a single aggressor… both… escalated each other"), acknowledges the strongest opposing evidence (Soviet domination of Eastern Europe), and establishes a line of reasoning (security dilemma + mutual misperception) that the documents can support.
Organize the seven-or-five documents into analytical groups rather than walking through them one by one. Here, three groups serve the thesis:
The grouping itself makes the argument: Groups A and B are mirror images, each side blaming the other — which is the documentary evidence for a security dilemma.
Document 3 (Truman Doctrine) — sourcing the purpose and audience. Truman delivered this not as neutral analysis but to persuade a reluctant Congress and public to fund intervention in Greece and Turkey and to commit the United States to a new global role. Because his purpose was to mobilize support, he framed the issue in stark, universal terms — "free peoples" against "subjugation" — which inflates a regional aid request into a worldwide moral crusade. This rhetoric is itself evidence: it shows how the American side constructed the Soviet threat for domestic consumption, which a revisionist would cite as containment escalating the conflict.
Document 4 (Novikov Telegram) — sourcing the point of view and historical situation. Novikov was a Soviet diplomat reporting to his own government (the telegram was solicited by Foreign Minister Molotov), not addressing the public. Because his audience was the Kremlin and his point of view was that of a Marxist-Leninist official, he naturally read American behavior through the lens of "monopoly capital" and "imperialism" — confirming Moscow's prior assumptions. Its value is not as objective truth but as a window into how Soviet leaders perceived American intentions: each superpower's internal documents reveal a mirror-image fear of the other, the heart of the security-dilemma argument.
| Rubric Category | Points | What earns it here |
|---|---|---|
| Thesis / Claim | 1 | A historically defensible thesis with a line of reasoning — the model evaluates both sides' responsibility rather than naming one villain. |
| Contextualization | 1 | Situate the prompt in a broader context — e.g., the collapse of the Grand Alliance and the devastation/power vacuum left by World War II. |
| Evidence from Documents | 2 | +1 for using the content of at least 3 documents to address the prompt; +1 for using at least 4 to support the argument (the grouping above uses all five). |
| Evidence beyond the Documents | 1 | One specific, relevant outside example not in the docs — e.g., the Berlin Blockade/Airlift (1948–49), the Yalta free-elections pledge, or NATO (1949). |
| Sourcing (HIPP) | 1 | Explain, for at least two documents, how HIPP is relevant to the argument — the model does this for Docs 3 and 4. Naming the author's bias is not enough; you must explain why it matters for the argument. |
| Complexity | 1 | Demonstrate a nuanced understanding — e.g., using the mirror-image Groups A and B to argue a security dilemma, or weighing traditionalist against revisionist interpretations even-handedly. |
MCQ Solutions
DBQ Partial (Thesis · Grouping · Sourcing) — see section (g). A strong response: states a defensible, two-sided thesis framing the origins as a security dilemma rather than one nation's fault; groups the documents analytically (Western case: Docs 1, 3 / Soviet case: Docs 2, 4 / economic dimension: Doc 5) rather than summarizing them in sequence; and sources at least two documents with genuine HIPP analysis that explains why the author's purpose or point of view matters to the argument (modeled for Docs 3 and 4). For the full DBQ it would add contextualization (the breakdown of the Grand Alliance amid WWII's devastation), at least one piece of outside evidence (e.g., the Berlin Blockade/Airlift, Yalta, or NATO), and a complexity move (weighing traditionalist vs. revisionist interpretations even-handedly). Remember that Document 5 is representative, not authentic, and must not be quoted as a real person's words.
EuroIQ · Lesson 23 of 25 · Period 4 · Unit 9: The Cold War, Decolonization, and European Integration
This lesson is exam-prep study material aligned to the AP® European History Course and Exam Description. AP® is a trademark registered by the College Board, which is not affiliated with and does not endorse this product. Cold War-era ideologies and propaganda — communist and anti-communist alike — are presented here as historical phenomena to be analyzed, never endorsed. Dates, attributions, and translations are drawn from standard scholarly sources; readers should consult primary editions for exact wording. Documents in section (g) are labeled authentic or representative; representative documents are composites for practice and are not real quotations.
Content pending external history review.