Lesson Plans: Grades 9-12

Lesson 3: Japan's "Southern Advance" and the March toward War, 1940–1941

A We The People Resource


The Lesson


Ribbentrop, Kurusu, and Hitler negotiate the Tripartite Pact, 1940.

Ribbentrop, Kurusu, and Hitler negotiate the Tripartite Pact, 1940.

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

Go to the related interactive

America on the Sidelines: The United States and World Affairs, 1931–1941

comprehensive student interactive giving the user a full scope of America's political and diplomatic responses to world events between the two world wars.

For the Japanese leadership, events in Europe during the first half of 1940 offered new opportunities for resolving the war in China, which had been going on since 1937. A "southern advance" into the British, French, and Dutch colonies of Southeast Asia could serve both to cut off the Chinese from Western aid, and to provide a source for raw materials that otherwise would have to be purchased from the United States. However, such a course ran the definite risk of war with the United States—a risk that Tokyo was ultimately willing to accept.

In this lesson students will examine primary documents and maps to discover why Japan embarked on its "southern advance." They will also consider the U.S. response to this new policy, and how it contributed to war between the United States and Japan.

Guiding Questions

Was the "southern advance" a reasonable attempt to address to Japan's international dilemma, or was it a reckless step toward war?

Learning Objectives

After completing this lesson, students should be able to

  • Define what Japanese leaders meant by the "southern advance," and explain why they opted to pursue it.
  • Articulate the U.S. response to the "southern advance," and assess whether it was a reasonable one.
  • Explain why Tokyo decided in September 1941 to prepare for war against the United States.


By 1940 the Japanese war against China—euphemistically referred to in Tokyo as the "China Incident"—was in its fourth year, and victory remained nowhere in sight. The Japanese Army seemed to win every battle, but the Chinese had ample room for retreat. China's capital was now located far to the West, in Chungking, and the Chinese were receiving substantial aid from abroad, mostly from the United States and the Soviet Union. The Japanese occupied the wealthiest, most developed parts of China, but they barely had enough men to garrison their conquests, let alone penetrate deeper into Chinese territory.

This grim situation explains why Tokyo looked upon the German victories of April–July 1940 with such excitement. In a matter of months Hitler's armed forces had conquered Denmark, Norway, Belgium, the Netherlands, Luxembourg and France. Great Britain remained without great-power allies, with only the English Channel standing between Britain and the might of the German Army.

The Japanese were less interested in Europe per se than they were in Europe's possessions in Asia. The British colonies of Burma and Hong Kong, and the French colony of Indochina (modern-day Vietnam, Laos, and Kampuchea) were all known for being conduits for U.S. aid to Chungking. In addition, several European possessions in Southeast Asia were rich in raw materials that were vital to Japan's war effort—particularly the Netherlands East Indies, home to vast oil reserves.

The opportunities presented by recent developments were summarized in a document called "General Principles to Cope with the Changing World Situation," which Japanese military and government leaders agreed to in late July 1940. In an effort to bring victory in the "China Incident," Tokyo would seek better relations with Germany, and would pressure the beleaguered British into preventing supplies bound for China from passing through their colonial possessions. Most importantly, Japan would launch a "southern advance" aimed at bringing the natural resources of Southeast Asia under its control. Japan's leaders recognized that all of this would involve a "natural deterioration of relations with the United States," but this was a chance well worth taking.

Tokyo wasted little time in putting its "General Principles" into action. Under pressure from Japan, Great Britain agreed to close the "Burma Road," the most important avenue for U.S. aid to China. In September Japan joined Germany and Italy in signing the Tripartite Pact—often referred to as the Axis Pact—in which each signatory promised assistance in case any of the three found itself at war with any country "not involved in the European war or in the Chinese-Japanese conflict"; which, in practice, meant primarily the United States. Finally, Tokyo began to push into French Indochina, occupying the northern half of the country in September 1940 and the southern half in July 1941.

The critical question in Tokyo was how the United States would respond to all this. The Roosevelt administration was indeed alarmed, particularly by the Tripartite Pact and the occupation of Indochina. At the same time, the president was hampered by the fact that the American people had no desire to go to war. Moreover, Asia was not Roosevelt's highest priority in the summer and fall of 1940—the possibility of a German conquest of Great Britain appeared far more threatening for American national security. Therefore the U.S. responded with the same approach that it had used toward Japanese aggression that it had since 1937—economic sanctions. After the occupation of northern Indochina Secretary of State Cordell Hull announced an embargo on sales of scrap iron and steel to any country outside the western hemisphere except Great Britain. Since Japan was one of the largest buyers of this commodity, Tokyo knew immediately that the new policy was meant as an anti-Japanese measure.

The real blow, however, came in reaction to the Japanese occupation of southern Indochina. On July 26, 1941, President Roosevelt issued an executive order freezing all Japanese assets in the United States. This meant, in practice, that Japan could purchase nothing from the United States. While this was bad news for Tokyo for many reasons, the most devastating effect of the freeze was that it cut off Japan from its leading supplier of oil. Without oil, of course, the Japanese war effort in China could not continue. Therefore, unless trade relations were restored with the United States, or the oil reserves of the Netherlands East Indies could be brought under Japanese control, Tokyo would be faced with the prospect of a humiliating withdrawal from China.

It was therefore with a certain sense of desperation that Japan's leaders met at a conference, with the emperor himself in attendance, in early September 1941. All present agreed that the situation was grave, and that Japan's military power would begin to deteriorate rapidly in a few months. Therefore, while efforts to reach some sort of compromise with the Americans would continue, the country had to prepare for war in the near future. The "southern resource area," particularly the Dutch East Indies and the British colony of Malaya, had to be secured quickly, and this would certainly mean war with Great Britain. Under those circumstances, would the United States remain neutral, or come to Britain's aid? There was no way of knowing for certain, but the U.S. Navy was the only force in the region capable of interfering with Japan's plans in any serious way. If Tokyo tried to fight only the British, the Americans, striking from the Philippines or from Pearl Harbor, could inflict major damage to Japanese forces. The answer seemed clear—if there were to be war, the U.S. Pacific Fleet had to be neutralized.

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.
  • Finally, familiarize yourself with the interactive timeline "America on the Sidelines: The United States and World Affairs, 1931–1941 that accompanies this lesson. This timeline will, through text and maps, guide students through the major events in Asia in the 1930s, and will ask students for each event to identify (choosing from among a menu of options) how the United States responded to it. This lesson will focus on the events of September 1940 through September 1941.
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. Japan's "Golden Opportunity"

In this activity, students will consider how developments in Europe caused a change in Japanese strategy in 1940, as well as the implications of this new approach for the United States.

To begin, briefly review with students the general situation. Remind them that the "China Incident" has now been going on for nearly four years, and that China still refuses to give in to Japanese demands. The United States has been providing assistance to China, and that assistance has been reaching Chungking via three main routes—British-owned Burma, British-owned Hong Kong, and French-owned Indochina. Show students these locations on a map; if no appropriate map is available in the classroom, project or direct students to this map, available at the Campaign Atlas site of the U.S. Military Academy at West Point, which is linked from the EDSITEment-reviewed resource History Matters. Finally, inform them (or review with them, if this has already been covered in class) that Germany in the spring of 1940 conquered France, leaving Great Britain the only major country at war with Hitler. This means, of course, that neither France nor Britain was in a position to defend their Asian colonies effectively.

Announce to the class that it is now the summer of 1940. Break the class into an even number of groups of 3–5. Half of these groups are to represent delegations of diplomats from Japan, and the other half delegations of diplomats from the United States. Explain to them that they are part of a summit conference that is being held between the Japanese and the United States, in which they discuss the future of East Asia.

Give the Japanese delegations the following document, found in its excerpted form on pages 1–3 of the Text document, and in its entirety at the site "WWII Resources," which is linked from the EDSITEment-reviewed resource Digital History:

Likewise, assign the following document, found in its excerpted form on pages 4–6 of the text document, and in its entirety at WWII Resources, to the U.S. delegations:

For homework, students are to read their respective documents and develop at least five questions that they would ask the opposing delegation. In class the next day, allow each delegation to meet briefly (approximately 10–15 minutes) to plan an opening statement. The opening statement should be a summary of their policies on East Asia. Students in their groups should also rank the questions that they have drafted in order of their importance (with the understanding that there might not be time to get to all the questions).

To begin the summit conference, select one of the groups on the Japanese side to present its opening statement, and then have one of the American groups give its statement. Next choose a Japanese group to ask one of its questions, and have an American group answer it. Then have an American group ask a question, and a Japanese group answer it. Each group should have at least one opportunity to speak.

When there are about ten minutes left in class, engage students in a class discussion, asking them if they think that the U.S. response to Japanese aggression (again, economic sanctions) was effective, or if there should have been a change of strategy at this point.

Activity 2. Japan's Decision for War

After Japan invaded Indochina, the United States responded with more economic sanctions. Japan, in desperation, decided that the time to act had to come sooner rather than later. In September 1941, Japanese leaders, including the Emperor, met to discuss their situation. In this activity, students will review events in East Asia and read documents from these meetings to determine Japan's plans.

To begin, direct students to the interactive timeline. Give students ample time (about 30 minutes) to study the events in Asia from July 1940 through September 1941. As students go through the events of that period, ask them to consider the various options available to the United States—listed along the left-hand side—and for each event select what they think the actual response was. If they choose the wrong response, they should continue to make selections until they have found find the right one. As they use the interactive they should make a list of the events (with dates), and the U.S. responses. In addition, they should make note of the locations indicated in the interactive by marking them on their blank maps.

Go to the related interactive

When students are done with the interactive hand them the following documents, found in their excerpted form on pages 7-11 of the Text Document, and in their entirety at WWII Resources:

Once students have read the documents, they are to imagine that they are in attendance at an Imperial Conference in Japan in 1941. Based on what they have read, students should compile lists of reasons for and against a war with the United States. When they have finished, hold a class discussion in which students offer their opinions on whether or not Japan should go to war. If they decide against war, ask what response should Japan make to U.S economic sanctions.


Student participation in the two activities might be assigned a grade. Teachers may also wish to grade the lists of questions that students developed in the first activity, or the lists of arguments for and against war that they compiled in the second.

Upon completion of this lesson, students should also be able to write a short essay (2–4 paragraphs), answering the following:

Was the "southern advance" a reasonable attempt to address Japan's international dilemma, or was it a reckless step toward war?

In addition, students should be able to locate the following on a blank map of East Asia:

  • French Indochina
  • Burma

Finally, students should be able to identify and explain the significance of the following:

  • Burma Road
  • Tripartite Pact

Extending The Lesson

Teachers may wish to have their students read the actual text of the Tripartite Pact, which is available at the EDSITEment-reviewed resource The Avalon Project. Students should make careful note of the language; what specifically does it obligate the other signatories to do if one of them were to go to war against the United States? Japanese diplomats in 1940–41 repeatedly told the Roosevelt administration that Japan would not feel obligated to go to war if the United States went to war against Germany. Should the administration have felt reassured by this?

Tokyo in spring 1941—that is, before the occupation of southern Indochina and the freezing of Japanese assets in the United States—made an attempt to reach a comprehensive agreement with the Americans on East Asia. The Japanese proposal and the U.S. reply may both be found at "World War II Resources," which is linked from the EDSITEment-reviewed site Digital History. These documents are helpful in showing the gap that existed between the United States and Japan on several fundamental issues, thus helping to explain why a diplomatic settlement was unlikely.

Japan's Prime Minister, Prince Fumimaro Konoye, delivered an address to the Imperial Diet on January 21, 1941, in which he laid out Japan's overall foreign policy goals. The text of this speech is also available at "World War II Resources." It might be a useful exercise to have students read it, noting that euphemistic language that Konoye used to justify Japanese aggression against China.

Selected EDSITEment Websites

The Basics

Grade Level


Time Required

2-3 class periods

Subject Areas
  • History and Social Studies > Place > Asia
  • History and Social Studies > U.S. > The Great Depression and World War II (1929-1945)
  • History and Social Studies > Themes > War and Foreign Policy
  • Compare and contrast
  • Critical analysis
  • Critical thinking
  • Debate
  • Evaluating arguments
  • Historical analysis
  • Internet skills
  • Interpretation
  • Making inferences and drawing conclusions
  • Online research
  • 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

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