What was the primary goal of the u.s. strategy of island hopping in the pacific?

Background

While the primary Allied effort continued to be focused against Germany until the spring of 1945, public sentiment in the United States was very much in favor of doing more than remaining on the defensive in the Pacific. The crushing victory over the Japanese Navy at the battle of Midway, and the tremendous output of American industry made it possible to go on the offensive against Japan even before the end of 1942. By early 1943 the enemy had been driven from Guadalcanal, and the long slow process of overcoming the Japanese defensive perimeter began.

Allied military planners decided on a two-pronged approach to the Pacific. One drive, spearheaded by the army and led by General Douglas MacArthur, would continue through the Solomon Islands, then through New Guinea, and finally liberate the Philippines. At the same time the U.S. Navy and Marines, under the overall command of Admiral Chester Nimitz, would mount a series of amphibious operations against enemy positions in the Gilbert, Marshall, Caroline and Mariana Island chains. Eventually the two offensives would join together for an anticipated invasion of the Japanese home islands.

To carry out these offensives MacArthur and Nimitz would employ a strategy called "leap-frogging." Allied military planners reasoned that it would not be necessary to drive the Japanese from every one of their island strongholds—the key to victory would be to overcome key points in the enemy defense and seize only those islands that were most strategically valuable. By early 1944 the Americans could count on virtually unchallenged control of the skies and most of the sea-lanes, so that certain Japanese positions could be safely bypassed—their garrisons, cut off from their supply lines, would be left to "wither on the vine."

Both MacArthur and Nimitz would make steady progress in 1943 and 1944, but as time went on, Japanese troops increasingly fought to the death, so casualties on both sides were often staggeringly high. Realizing that an invasion of Japan itself would likely cause even more loss of life, President Harry S. Truman—who succeeded Roosevelt after the latter's death in April 1945—decided to use a powerful new weapon: the atomic bomb. In August two such bombs were dropped, on the cities of Hiroshima and Nagasaki. On 10 August Japan surrendered, bringing World War II at long last to a close.

Content Standards

NCSS.D2.His.1.9-12. Evaluate how historical events and developments were shaped by unique circumstances of time and place as well as broader historical contexts.

NCSS.D2.His.2.9-12. Analyze change and continuity in historical eras.

NCSS.D2.His.3.9-12. Use questions generated about individuals and groups to assess how the significance of their actions changes over time and is shaped by the historical context.

NCSS.D2.His.4.9-12. Analyze complex and interacting factors that influenced the perspectives of people during different historical eras.

NCSS.D2.His.5.9-12. Analyze how historical contexts shaped and continue to shape people’s perspectives.

NCSS.D2.His.12.9-12. Use questions generated about multiple historical sources to pursue further inquiry and investigate additional sources.

NCSS.D2.His.14.9-12. Analyze multiple and complex causes and effects of events in the past.

NCSS.D2.His.15.9-12. Distinguish between long-term causes and triggering events in developing a historical argument.

NCSS.D2.His.16.9-12. Integrate evidence from multiple relevant historical sources and interpretations into a reasoned argument about the past.

Preparation

Review the lesson plan. Locate and bookmark suggested materials and links from EDSITEment-reviewed websites. Download and print out selected documents and duplicate copies as necessary for student viewing. Alternatively, excerpted versions of these documents are available as part of the downloadable PDF.

Download the blackline master for this lesson, available here as a PDF. This file contains excerpted versions of the documents used in the first and second 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, and which shows the locations of important events in the Pacific theater. Clicking on these locations will bring up pop-ups that include a paragraph or two of basic information about what happened there, as well as links to pages with more in-depth coverage, plus relevant campaign maps, photographs, and/or personal accounts by those who were there.

Working with 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 Educator Resources of the National Archives, which features a set of Document Analysis Worksheets. Finally, History Matters offers pages on "Making Sense of Maps" and "Making Sense of Oral History" which give helpful advice to teachers in getting their students to use such sources effectively.

Lesson Activities

Activity 1. Allied Strategy in the Pacific, 1943–1945

Using the documents and the map below, have students make a list of the areas that the Allies hoped to capture. After they have done this, they should click on locations 18–36 on the interactive map. To help ensure that students use the map to its full advantage, teachers might wish to have them complete the "scavenger hunt" that is included in the Master PDF (pages 7–9 in the PDF). Based on their examination of these resources, students should be able to discuss broadly the overall Allied strategy and why it was adopted. Further, they should be able to identify which strategic goals were met, and which were not.

Direct students to the following documents, either online or as handouts printed from the Master PDF (pages 1–6 of the PDF).

  • From Hyperwar, accessible via the EDSITEment-reviewed site of the Naval Historical Center
  • JCS 287/1, the Strategic Plan for the Defeat of Japan
  • From the site of the FDR Presidential Library, accessible via the EDSITEment reviewed resource Digital Classroom
  • Report by the Joint War Plans Committee on operations in the Pacific and Far East in 1943–44

Have the students answer the following questions based on their reading:

  • What had to occur before Allied forces could concentrate solely on the Pacific Front?
  • What had to occur before an invasion of Japan could take place? Why?
  • Why was China so important to success in the war against Japan?
  • Why were lines of communication so important to military planners?
  • What were planners hoping would happen once the United States gained control of the seas?
  • What were the primary objectives of U.S. operations for 1943–44?

Next ask the students to consult the interactive map, which will demonstrate how the offensive played out in reality.

Activity 2. Truman's Decision to Drop the Atomic Bomb

Distribute to the students the set of documents in the Master PDF (pages 10–15 in the PDF) pertaining to President Truman's decision to use the atomic bomb against Hiroshima. These are excerpts from longer documents found online at the EDSITEment reviewed resource Project Whistlestop.

  • Notes of the Interim Committee Meeting, May 31, 1945
  • Notes of the Interim Committee Meeting, June 21, 1945
  • Minutes of a meeting held at the White House, June 18, 1945
  • Pages from President Truman's diary, July 1945
  • Memorandum for General Arnold
  • Draft of a White House Press Release, August 6, 1945
  • Translation of a leaflet dropped on Japanese cities, August 6, 1945

Based on their reading of these documents, students should then write an essay in response to the following: "Why did President Truman decide to use the atomic bomb against the Japanese city of Hiroshima?"

Activity 3. Japan's Decision to Surrender: A Debate

Print out and distribute to students the set of documents in the blackline master dealing with the decision of the Japanese government to surrender in the summer of 1945 (pages 16–23 in the PDF). These include:

From the EDSITEment reviewed resource The Avalon Project at Yale University:

  • The Cairo Declaration
  • From Hyperwar, accessible via the EDSITEment-reviewed site of the Naval Historical Center:
  • The Potsdam Declaration
  • The Imperial Rescript of August 15, 1945
  • Excerpts from the postwar interrogation of Japanese Prime Minister Toyoda Soemu

After the students have had an opportunity to read through the documents, divide the class into pairs and give them the following resolution to be debated:

“The use of the atomic bombs caused Japan to surrender.”

Have one student in each pair take the pro side of the debate, and the other take the con side. Each pair should use the worksheet for this activity (page 24 in the PDF) to conduct a silent "Yeah, but" debate. The first student should begin by citing a fact from one of the documents in support of the resolution; this should be written on the "pro" side of the worksheet. The second student then follows by citing another fact in opposition to that point. This should continue until one student or the other runs out of relevant facts.

After students have completed the debate, teachers may wish to have the class discuss this topic, bringing in what they have learned from the second activity to address the larger issue of whether or not Truman's decision to drop the bomb was wise.

Assessment

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

  • What was the Allied strategy for defeating Japan after 1942?
  • Why did President Truman decide to use the atomic bomb? Why was this decision controversial?
  • Why did Japan surrender? How important a factor was the atomic bomb in the decision to surrender?

Students should also be able to identify the following locations on a blank map of the Pacific region, available at this site, which is accessible via the EDSITEment-reviewed resource History Matters:

  • Solomon Islands
  • Gilbert Islands
  • Marshall Islands
  • Mariana Islands
  • Iwo Jima
  • Okinawa
  • Manchuria

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

  • "leap-frogging"
  • Philippine Sea
  • Kamikaze
  • Leyte Gulf
  • "Enola Gay"
  • Atomic bomb

Lesson Extensions

Any of the engagements listed as locations on the interactive map could be topics for research papers, PowerPoint presentations, etc., as each pop-up includes a wealth of source material on the subject.

A great many movies have been made about this phase of the war in the Pacific—Sands of Iwo Jima (1949), Operation Pacific (1951), Run Silent, Run Deep (1958), In Harm's Way (1965), and Windtalkers (2002)—are just a few examples. Students could be asked to watch one of these movies and write an essay comparing it to the real events on which the film was based. Here again, the sources linked from the locations on the interactive map will be useful for background.

Selected EDSITEment Websites

  • National Archives Educator Resources
    • Document Analysis Worksheets
    • Franklin D. Roosevelt Presidential Library and Museum
      • Operations in the Pacific and Far East, 1943–44
  • History Matters (GMU)
    • Making Sense of Maps
    • Making Sense of Oral History
    • Rutgers Oral History Archives
    • Best of History Websites
    • World War II Sites
      • Pearson-Longman Instructor Resources
      • Blank Map—WWII in the Pacific
  • Naval Historical Center
    • Oral Histories of World War II
      • Hyperwar: World War II on the World Wide Web
      • The Potsdam Declaration, 1945
      • The Imperial Rescript of 15 August 1945
      • Interrogation of Adm. Toyoda Soemu
      • JCS 287/1, the Strategic Plan for the Defeat of Japan
  • The Avalon Project at Yale Law School
    • The Cairo Conference, 1943
  • Project Whistlestop (Truman Library)
    • The Decision to Drop the Atomic Bomb
      • Notes of the Interim Committee Meeting, May 31, 1945
      • Minutes of Meeting Held at the White House, June 18, 1945
      • Notes of the Interim Committee Meeting, June 21, 1945
      • Pages from President Truman's diary, July 16, 1945
      • Memorandum for General Arnold regarding the Groves Project, July 24, 1945
      • Draft of a White House press release, "Statement by the President of the United States," ca. August 6, 1945
      • Translations of two leaflets dropped on Japanese cities shortly after the first atomic bomb was dropped, ca. August 6, 1945
      • United States Strategic Bombing survey "Japan's Struggle to End the War," July 1, 1946

What was the purpose of the US strategy of Island Hopping quizlet?

Island hopping was a military strategy of capturing only certain Japanese islands in the Pacific and bypassing others, leading to the Japanese mainland. Battle between the Soviets and Germany in Stalingrad in the summer of 1942; Soviet victory greatly weakened Germany's forces.

What was the US military strategy in the Pacific?

Leapfrogging, also known as island hopping, was a military strategy employed by the Allies in the Pacific War against the Empire of Japan during World War II.