AP European History

## Learning Outcomes

- Explain why wartime cooperation between the Allies broke down after **1945**
- Identify the roles of **Yalta**, **Potsdam**, and the **Iron Curtain** in dividing Europe
- Understand how Soviet control spread across Eastern Europe and why the West reacted strongly
- Trace the development of **containment**, the **Truman Doctrine**, and the **Marshall Plan**
- Explain why Germany and Berlin became the clearest symbols of Cold War division
- Distinguish political, economic, and military forms of division in postwar Europe
- Use specific evidence, including dates, leaders, and crises, in AP-style arguments about causation and comparison

## AP European History Syllabus

For the AP European History, you are expected to understand postwar tensions that divided Europe, with a focus on the following syllabus points:

- Know that the wartime alliance between the United States, Britain, and the Soviet Union weakened rapidly after **1945**
- Identify the significance of the **Yalta Conference (February 1945)** and the **Potsdam Conference (July-August 1945)**
- Explain what Churchill meant by the **Iron Curtain** in **1946**
- Understand how **Sovietization** created communist states in Eastern Europe through pressure, rigged elections, purges, and one-party rule
- Explain the policy of **containment**, including **George Kennan**, the **Truman Doctrine (1947)**, and the **Marshall Plan (1947)**
- Understand why Germany was divided into occupation zones and why **Berlin** became a flashpoint
- Recall the significance of the **Berlin Blockade and Airlift (1948-1949)** and the creation of the **FRG** and **GDR** in **1949**
- Identify how **NATO (1949)** and the **Warsaw Pact (1955)** formalized Europe’s division into two blocs

## Test Your Knowledge

_Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, look more closely at that area during your revision._

1. Why did cooperation between the Western Allies and the Soviet Union weaken so quickly after World War II?
2. What were the key differences between the Yalta and Potsdam conferences?
3. How did Soviet control spread across Eastern Europe after 1945?
4. Why did the Berlin Blockade become such an important early Cold War crisis?
5. How did containment divide Europe politically, economically, and militarily?

## Introduction

After **World War II**, Europe did not simply recover and return to peace. Instead, it became the central battleground of a new kind of conflict: the **Cold War**. This was not a direct full-scale war between the United States and the Soviet Union. It was a struggle over power, security, ideology, and the future shape of Europe. For AP European History, this topic matters because it connects wartime diplomacy, postwar reconstruction, decolonization, nationalism, and the long division of the continent.

The key idea is that Nazi Germany’s defeat removed the common enemy that had held the alliance together. Once that happened, tensions over Germany, Eastern Europe, and postwar influence became impossible to hide. By the late 1940s, Europe had split into an eastern communist bloc under Soviet domination and a western bloc tied to the United States.

> **Key Term: Cold War**
> A prolonged political, ideological, military, and economic rivalry after 1945 between the Soviet Union and the Western powers, especially the United States, that stopped short of direct total war between the two superpowers.

### Why wartime cooperation collapsed after 1945

The Cold War did not begin from nowhere in **1945**. Suspicion already existed during the war. The Soviet Union distrusted Britain and the United States because they delayed opening a second front in Western Europe. Western leaders distrusted Stalin because of the history of communism since **1917** and Soviet repression at home. Wartime unity was real, but it was limited and practical: all three powers needed to defeat Hitler.

After victory, these tensions sharpened because the Allies had very different goals. Stalin wanted security. The Soviet Union had suffered catastrophic losses and had been invaded from the west more than once. From his point of view, friendly governments in Eastern Europe would create a buffer zone. Britain and the United States, by contrast, emphasized self-determination, freer political systems, and open economic recovery. That clash meant the same event could be read in two ways: as Soviet defense or as Soviet expansion.

> **Key Term: Sovietization**
> The process by which Eastern European states were brought under Soviet control through communist parties, repression of opposition, one-party rule, and state-directed economies.

This is why students should avoid a simple explanation such as “Yalta caused the Cold War.” Yalta exposed disagreements, but Europe was already moving toward rival spheres of influence as the Red Army advanced westward and Anglo-American armies moved into Western Europe.

A major case is **Poland**. Stalin intended to dominate its future because Soviet troops were already on the ground. Western leaders could demand free elections, but they lacked the power to enforce them without risking another war. Similar pressures later shaped politics in **Romania**, **Bulgaria**, **Hungary**, and **Czechoslovakia**.

> **Test Tip:** For AP causation questions, do not give one cause only. A stronger answer links **ideology**, **security fears**, **power politics**, and **disputes over Germany and Eastern Europe**.

### Yalta, Potsdam, and the growth of mistrust

The **Yalta Conference** in **February 1945** is often remembered as a moment of wartime agreement, but it was also full of ambiguity. Roosevelt, Churchill, and Stalin agreed that Germany would be divided into occupation zones. They also discussed reparations and issued broad promises about liberated Europe, including “free elections.” The problem was that each side meant something different by those words. For the West, they suggested political choice. For Stalin, they did not override Soviet security interests.

At **Potsdam** in **July-August 1945**, the mood was colder. Germany had surrendered, so the common emergency was gone. Roosevelt had died and been replaced by **Harry Truman**, who was more suspicious of Stalin than Roosevelt had been. Churchill was replaced during the conference by **Clement Attlee** after the British election. The United States had also successfully tested the atomic bomb. Disputes over reparations, Poland, and Eastern Europe became more open.

> **Key Term: Yalta Conference**
> The February 1945 meeting of Roosevelt, Churchill, and Stalin, where the Allies discussed postwar Europe, including Germany’s occupation and principles for liberated states.
>
> **Key Term: Potsdam Conference**
> The July-August 1945 meeting of Truman, Stalin, and Churchill/Attlee, where Allied tensions over Germany, reparations, and Eastern Europe became sharper.

Germany became the most important practical issue. At Yalta and after the war, Germany was divided into four zones: American, British, French, and Soviet. Berlin, although deep inside the Soviet zone, was also divided into four sectors. At first, this looked temporary. In practice, each occupying power reshaped its own zone.

In the Soviet zone, the USSR claimed to support democratic parties, but it gradually took control. In **1946**, the communist **KPD** was forcibly merged with the **SPD** to help build a one-party structure under **Walter Ulbricht**. This mattered because it showed a pattern later used elsewhere in Eastern Europe: first coalition, then pressure, then exclusion of rivals, then communist dominance.

Elsewhere, Sovietization followed similar methods. In **Hungary**, communists used what later became known as **salami tactics**: opponents were removed slice by slice until little real opposition remained. In **Czechoslovakia**, the **1948 coup** was especially alarming in the West because Czechoslovakia had been one of the stronger prewar democracies. Its fall convinced many that Stalin was not merely protecting Soviet borders but extending communist power.

Churchill’s **1946** speech gave this new reality a memorable phrase.

> **Key Term: Iron Curtain**
> Churchill’s term for the political and ideological division separating Soviet-dominated Eastern Europe from Western Europe.

### Containment, Germany, and the division of Europe into two blocs

Western reaction developed step by step. First came diagnosis, then policy, then alliance. **George Kennan’s** Long Telegram argued that the Soviet Union was hostile to coexistence and had to be resisted with firm, patient pressure. This became **containment**.

> **Key Term: containment**
> The U.S. policy of preventing further expansion of Soviet influence rather than trying to destroy Soviet power directly.

Containment first appeared clearly in the **Truman Doctrine** in **1947**. Truman asked Congress to support **Greece** and **Turkey**, arguing that the United States must aid peoples resisting subjugation. This is important because it turned anti-communism into an open, global commitment.

The economic side followed with the **Marshall Plan** in **1947**. The United States offered huge financial aid for European recovery. This was not only generosity. It aimed to rebuild economies, reduce social breakdown, and make communism less attractive. Western Europe accepted the aid. Stalin rejected it and pressured Eastern European states to refuse it too.

> **Key Term: Truman Doctrine**
> The 1947 U.S. policy of supporting states threatened by communist pressure, first applied to Greece and Turkey.
>
> **Key Term: Marshall Plan**
> The 1947 American program of economic aid to rebuild Europe and strengthen Western states against communism.

The Soviet response tightened the split. **Cominform** helped discipline communist parties politically. The **Molotov Plan** and later **Comecon** organized Eastern bloc economic coordination. This is a distinction students often miss: division happened not just politically, but also economically. Western Europe rebuilt through American-backed recovery and increasing integration. Eastern Europe was tied more closely to Moscow’s system.

Germany showed this separation most clearly. The American and British zones merged into **Bizonia** in **1947**; later French participation helped create **Trizonia**. The **1948 currency reform**, introducing the Deutsche Mark in the western zones, accelerated separation. Stalin answered with the **Berlin Blockade** of **June 1948-May 1949**, cutting land and water access to West Berlin.

The Western response was the **Berlin Airlift**. Supplies were flown into the city for almost a year. Stalin eventually lifted the blockade. This was a major Western success because it prevented Berlin from being forced into the Soviet sphere without direct war.

> **Key Term: Berlin Blockade**
> The Soviet attempt in 1948-1949 to cut off Western land access to West Berlin in response to growing western consolidation in Germany.
>
> **Key Term: Berlin Airlift**
> The Western air supply operation that sustained West Berlin during the Soviet blockade and forced Stalin to back down.

The consequences were huge. In **May 1949**, the western zones became the **Federal Republic of Germany (FRG)**, or West Germany. In **October 1949**, the Soviet zone became the **German Democratic Republic (GDR)**, or East Germany. Europe’s division had now become state-building.

Military division followed. **NATO** was formed in **1949** as a collective defense alliance. The Soviet bloc later answered with the **Warsaw Pact** in **1955**, especially after West Germany joined NATO.

> **Test Tip:** If asked how Europe was divided, organize your answer in three categories: **political** division through Sovietization and anti-communist states, **economic** division through Marshall Plan versus Soviet alternatives, and **military** division through NATO versus Warsaw Pact.

For AP essays, this structure works well because it shows analysis rather than description. You can then use Germany and Berlin as a case study proving the larger point.

### How to build an AP argument on this topic

A strong AP response needs more than a narrative list. It needs a claim about causation. A good thesis might argue that postwar tensions divided Europe because wartime cooperation masked deeper conflict over security, ideology, and the future of Germany, and that these tensions hardened through Sovietization in the east and containment in the west.

To develop that argument, use a clear chain:

- wartime alliance ends
- disagreement at Yalta and Potsdam becomes sharper
- Sovietization spreads in Eastern Europe
- Western leaders respond with containment
- Germany and Berlin become crisis points
- NATO and the Warsaw Pact formalize division

You can also show complexity by qualifying the argument. For example, Soviet behavior can be read both as defensive buffer-building and as coercive expansion. That kind of balanced interpretation is exactly what AP rewards.

## Key Point Checklist

_This article has covered the following key knowledge points:_

- After **1945**, wartime cooperation between the Allies broke down rapidly
- The Cold War grew from ideological conflict, security fears, disputes over Germany, and rivalry over Eastern Europe
- **Yalta (February 1945)** showed both cooperation and unresolved disagreement, especially over free elections
- **Potsdam (July-August 1945)** revealed sharper mistrust over reparations, Poland, and German policy
- The **Iron Curtain** described the division between Soviet-dominated Eastern Europe and the Western bloc
- **Sovietization** created communist one-party regimes across Eastern Europe through pressure, rigged politics, and repression
- The **1948 Czechoslovak coup** and communist takeover in **Hungary** helped convince the West that Stalin was expanding Soviet control
- **Containment** shaped U.S. policy, especially through the **Truman Doctrine** and **Marshall Plan**
- Germany was divided into occupation zones, and Berlin became the main early Cold War flashpoint
- The **Berlin Blockade and Airlift (1948-1949)** deepened division and helped produce two German states in **1949**
- **NATO (1949)** and the **Warsaw Pact (1955)** formalized Europe’s military division
- A strong AP answer explains Europe’s division in political, economic, and military terms

## Key Terms and Concepts

- Cold War
- Sovietization
- Yalta Conference
- Potsdam Conference
- Iron Curtain
- containment
- Truman Doctrine
- Marshall Plan
- Berlin Blockade
- Berlin Airlift


The Cold War - Postwar tensions divided Europe