Lesson Plans: Grades 9-12

Lesson 1: Sources of Discord, 1945–1946

A We The People Resource


The Lesson


President Harry S. Truman guided the United States through the early years of  the Cold War.

President Harry S. Truman guided the United States through the early years of the Cold War.

Credit: Image courtesy of American Memory at the Library of Congress.

The fact that the United States and the Soviet Union successfully cooperated in defeating the Axis Powers did not necessarily mean that the two countries would continue to get along in the postwar world. After all, the two were organized on radically different principles—democratic capitalism in the former, totalitarian socialism in the latter. By early 1945 it was clear that they would emerge as the world's two "superpowers," but it was also evident that they had conflicting visions for what that postwar world should look like. A number of issues divided U.S. and Soviet policy makers, but two loomed particularly large in 1945–46: the future of Germany and the future of Eastern Europe. As a result of these controversies the chances of continued cooperation between the superpowers seemed bleak.

This lesson will examine the U.S.-Soviet disagreements regarding Germany and Eastern Europe. Students will read excerpts from the agreements reached at Yalta and Potsdam, then, based on later documents, will study how these arrangements unraveled. Finally they will look at two opposing American views of the Soviet Union and of the strategy that the United States should use in dealing with it.

Guiding Questions

  • From the American perspective, why did wartime cooperation between the United States and the Soviet Union collapse in 1945–46?

Learning Objectives

  • Articulate the agreements made at Yalta and Potsdam regarding the nature of the postwar world.
  • Explain the differences that emerged regarding those agreements in the months following the end of the war in Europe.
  • Assess the strategic options available to the United States in 1946.


Franklin Roosevelt had repeatedly expressed optimism regarding the postwar relations between the United States and the Soviet Union. When differences between them emerged, he insisted, his personal relationship with Stalin would be enough to smooth them over. Whether he was right was impossible to say, but it became a moot point when FDR died in April 1945. Therefore it was Roosevelt's vice president, Harry Truman, who would be in the White House when serious problems developed.

At the Yalta and Potsdam Conferences of 1945 the United States, Great Britain, and the Soviet Union had reached agreement on a number of topics, particularly the fate of postwar Germany and Eastern Europe. Most importantly, at Yalta they issued a "Declaration of Liberated Europe," in which they pledged "to form interim governmental authorities broadly representative of all democratic elements in the population and pledged to the earliest possible establishment through free elections of Governments responsive to the will of the people."

But within a few months policy makers in the Truman administration had come to believe that Stalin was not living up to his side of those agreements. Instead it appeared as though the Russians were trying to create a series of puppet states in Eastern Europe. For their part, the Soviets argued that their security required "friendly" regimes along their border, and that Western-style democratic elections were unlikely to produce pro-Soviet governments. To Truman this seemed like a betrayal of everything that the Allies had fought for in their war against the Axis. Moreover, large numbers of Americans of Eastern European descent were inclined to agree with him.

As a result of this, the high hopes that FDR had for postwar cooperation had been largely dashed by late 1946, prompting a debate over what U.S. policy toward the Soviets should be. Some, like Secretary of Commerce Henry Wallace, argued that Stalin's need for security had to be acknowledged, even if it meant tolerating Soviet dominance over Eastern Europe. Others, like George Kennan, deputy head of the U.S. mission to Moscow during World War II, saw in the Soviet Union a growing threat to world peace—one that had to be met with firmness and, if necessary, military force.

Preparation Instructions

Review the lesson plan. Locate and bookmark suggested materials and links from EDSITEment-reviewed websites used in this lesson. Download and print out selected documents and duplicate copies as necessary for student viewing.

Download the Text Document for this lesson, available here as a PDF. This file contains excerpted versions of the documents used in the various activities, as well as questions for students to answer. Print out and make an appropriate number of copies of the handouts you plan to use in class.

Perhaps most importantly, you should become familiar with the interactive map which accompanies this lesson. This map shows the most important events in Europe from 1945 through 1949. By clicking on the numbered locations, pop-ups will appear with more information and, in some case, links to additional EDSITEment-reviewed websites. This lesson will encompass locations 1 through 7 on the map.

Analyzing primary sources

If your students lack experience in dealing with primary sources, you might use one or more preliminary exercises to help them develop these skills. The Learning Page at the American Memory Project of the Library of Congress includes a set of such activities. Another useful resource is the Digital Classroom of the National Archives, which features a set of Document Analysis Worksheets. Finally, History Matters offers helpful pages on "Making Sense of Documentary Photography" and "Making Sense of Maps" which give helpful advice to teachers in getting their students to use such sources effectively.

Lesson Activities

Activity 1. Plans for Postwar Europe

During conferences at Yalta (February 1945) and Potsdam (July-August 1945) the Allies concluded agreements for the postwar world; the most important concerned the fate of Germany and Eastern Europe. In this activity students will consider those agreements so that they will understand how they later unraveled. Begin the lesson by dividing the class into two groups. The first will be responsible for reading excerpts from the proceedings of the Yalta Conference, while the second will do the same for the Potsdam Conference. Both of these documents are available in their entirety at the EDSITEment-reviewed resource The Avalon Project. However, excerpted versions of both are available on pages 1–8 of the Text Document that accompanies this lesson.

As they work their way through the documents, students in each group should complete the corresponding worksheet (page 4 for Group #1, page 9 for Group #2), noting the agreements reached at each conference.

For background on these conferences, as well as reference to geographic locations, students should be directed to the interactive map.

After the students have read the documents and completed the worksheets (this might be assigned as homework) they should come together in class to list the main agreements reached at both Yalta and Potsdam. A good way of doing this might be to split up the groups, pairing each member of Group #1 with a member of Group #2 and having them compare their worksheets. The ultimate goal should be a comprehensive list of agreements made at Yalta and Potsdam.

For more advanced students, this activity might conclude with a class discussion comparing and contrasting the agreements made at Yalta with those reached at Potsdam. Students might also be asked to speculate on what problems they think were likely to arise from these agreements, and why.

Activity 2. The Breakdown of Cooperation

In the previous activity students will have learned about the agreements made regarding postwar Europe. In this exercise they will examine how the West and the Soviet Union had conflicting interpretations of these agreements. The result was a set of disputes that emerged in the first several meetings of the Council of Foreign Ministers, which was first established at Potsdam for the purpose of smoothing over relations among the former Allies.

Again divide the class into two groups. The first will read excerpts from accounts by U.S. Secretary of State James Byrnes on the First and Interim meetings of the Council, while the second will read excerpts from Byrnes' account of the Second Meeting. All three accounts are available in their entirety at the Avalon Project; however, excerpts are included on pages 10–17 of the Text Document.

Group #1:

Group #2:

Once the readings and worksheets have been completed (again, this might be usefully assigned as homework) the students should come together to compare their findings. As in the first activity, each student from Group #1 might be paired with a student from Group #2, or you could lead a discussion involving the entire class. In the end students should have a sense for which agreements reached at Yalta and Potsdam were not successfully carried out and why.

As in the last activity, more advanced students might be asked to consider, based on Byrnes's comments, how realistic were the goals and objectives set by the Allied Powers at Yalta and Potsdam.

Activity 3. Why did Cooperation Break Down?

The rapid breakdown of the agreements reached at Yalta and Potsdam left policy makers in Washington scrambling for explanations of why the Soviets were behaving as they were, and for ideas on how to manage relations between the two superpowers. In this activity students will read competing interpretations of recent events. These are available in their entirety at the EDSITEment-reviewed resources Teaching American History and History Matters, but excerpts are included on pages 1826 of the Text Document.

To begin, divide the class into two groups and assign each one of the readings listed below. Inform the students that their task will be to explain to President Truman (played by the teacher) why cooperation with the Soviet Union has broken down and what the United States should do as a result.

Group #1: Excerpts from George Kennan's "Long Telegram," February 22, 1946: (pages 1821 of the Text Document)

Group #2: "Achieving an Atmosphere of Mutual Trust and Confidence": Henry A. Wallace Offers an Alternative to Cold War Containment: (pages 2226 of the Text Document)

Whichever group they are in, students should answer the following questions to guide their reading (available as a worksheet on page 27 of the Text Document

  • Why, according to the author, had relations deteriorated between the United States and the Soviet Union?
  • Why, according to the author, did Americans distrust the Soviet Union?
  • Why, according to the author, did the Soviet Union distrust the United States?
  • What was the author's greatest fear regarding Soviet-American relations?
  • What were the author's recommendations for how U.S. policy toward the Soviet Union ought to be conducted?

Once the students have finished, select several members from each team (the number selected will vary according to the amount of time available) to offer their views on U.S.-Soviet relations. Based on these documents, members of the first group should argue for a policy of strength—that is, the threat of force—to resist Soviet demands. Members of the second group will most likely advocate a policy based on compromise, including a willingness to give in to certain Soviet demands.


After completing this lesson, students should be able to write brief (1–2 paragraph) essays answering the following questions:

  • How, in the eyes of the Truman administration, did Soviet behavior regarding Germany conflict with the sentiments expressed at Yalta and Potsdam?
  • How, in the eyes of the Truman administration, did Soviet behavior regarding Eastern Europe conflict with the sentiments expressed at Yalta and Potsdam?
  • Compare and contrast the arguments of George Kennan and Henry Wallace regarding U.S. policy toward the Soviet Union.

Alternatively, more advanced students might be asked to write a single essay that incorporates all of the above issues:

  • What accounts for the breakdown in relations between the United States and the Soviet Union after World War II? Is there anything that the United States could have done to avoid it?

Students should be able to identify and explain the significance of the following:

  • Yalta Conference
  • Potsdam Conference
  • James Byrnes
  • George Kennan
  • Henry Wallace

Finally, students should be able to identify the following locations on a blank map of post-1945 Europe and explain their importance to the worsening relations between East and West:

  • Germany (East and West)
  • Poland
  • Rumania
  • Bulgaria

Extending The Lesson

In some ways the story of the decline of U.S.–Soviet relations can be played out in the words of one man—President Harry Truman. By looking at a series of his diary entries from June and July 1945 students should be able to get a sense for how Truman moved from optimism to pessimism regarding the ability of the United States and the Soviet Union to work together in the postwar world. Images of these diary entries may be found at the Truman Library website (scroll down to the bottom of the page, under "Truman: In His Own Words").

Not surprisingly, the Soviets themselves had their own interpretation of events in 1945–46. The Soviet equivalent of Kennan's "Long Telegram" came from Nikolai Novikov, Moscow's ambassador to the United States, who tried to explain U.S. behavior in a telegram to the Kremlin. Teachers may wish to have students read this document, perhaps comparing and contrasting it to Kennan's. It is located at the EDSITEment-reviewed site Teaching American History.

One of the most influential speeches of the early Cold War years was given by Winston Churchill, former Prime Minister of Great Britain, to students at Westminster College in Missouri. Although Churchill did not coin the term "Iron Curtain" (it actually was first used by German Propaganda Minister Josef Goebbels in the final weeks of World War II), it was this speech that popularized it—so much so that to this day the address is usually referred to as the "Iron Curtain Speech." The relevant excerpts from the speech are available at the Internet Modern History Sourcebook, which is accessible via the EDSITEment-reviewed site History Matters.

Selected EDSITEment Websites

The Basics

Grade Level


Time Required

3-4 class periods

Subject Areas
  • History and Social Studies > U.S. > Postwar United States (1945 to early 1970s)
  • Critical analysis
  • Critical thinking
  • Developing a hypothesis
  • Discussion
  • Gathering, classifying and interpreting written, oral and visual information
  • Historical analysis
  • Interpretation
  • Representing ideas and information orally, graphically and in writing
  • Textual analysis
  • Using primary sources
  • Vocabulary
  • Writing skills
  • John Moser, Ashland University (Ashland, OH)
  • Lori Hahn, West Branch High School (Morrisdale, PA)


Activity Worksheets
Student Resources