Understanding the Complexities of War in American History: Select Case Studies

This complete module with all materials may be downloaded as a PDF here.

Michael Breakey

Georgia Northwestern Technical College

Rome, Georgia

Infamy Speech

Franklin Delano Roosevelt, World War II Infamy Speech. Source: YouTube at https://tinyurl.com/kpnb8my.

This module was developed and utilized in an introductory community college U.S. history course but can be utilized in standard or honors-level high school history courses.

While this module is chronological, it encompasses a series of events during separate periods of American history and thus may be most effectively used during various sections of a typical U.S. history course.

Estimated module length: Three hours (excluding enrichment/supplemental activities)


Article 1, Section 8 of the US Constitution grants the legislative branch the expressed power to declare war. Against the backdrop of unremitting war in Europe, the founders debated and decided the articulated power should rest with the U.S. Congress. Eleven times the U.S. Congress has approved formal declarations of war, with the last declaration occurring on June 4, 1942, against three European nations. Since World War II, the constitutional directive has not been followed.

The module is designed to first introduce students to the views of the Founding Fathers on armed conflict and government as they developed the US Constitution—specifically the process for the formal declaration of war against an adversary. The module will use background information from European wars of the eighteenth century as a bridge to understanding the debate at both the Philadelphia Convention and the language and intent of the Constitution. The remainder of this module includes case studies of the contextual events and decisions that led to three armed conflicts and post-World War 11 developments that have increased executive disposition to involve the U.S. in military conflict.

It is impossible for students to consider either formal declarations of war or acts of war unaccompanied by formal declarations without basic knowledge of the issues that lead to particular wars and some understanding of military history. The latter field is now often neglected both in university history departments and in high school and college classrooms. This module includes resources that help students understand not only how knowledge of military history influenced the authors of the Constitution but also three influential wars in American history: The Mexican War, World War II (with an emphasis on the Pacific Theater), and the Korean Conflict.


Students will:

Understand the relationship between eighteenth-century European conflict and the political reactions of the Founders to prevent the relentless warfare experienced in Europe.

Examine examples of positions of several delegates at the Philadelphia Convention as they developed the declaration of war against an adversary in the U.S. Constitution through critically analyzing selected primary source excerpts of delegates’ written positions, and Article 1, Section 8 of the Constitution.

Review the Mexican War and World War II (with specific focus on the events of December 1941) in order to understand the process of declaring war per the constitutional process.

Review and analyze post-World War II U.S. foreign policy—specifically the Truman Doctrine, the National Security Act of 1947, and National Security Council Resolution 68 (NSC-68)—to understand the changes in U.S. foreign policy related to the rising tensions of the Cold War.

Examine the U.S. and U.N. intervention in the Korean War with a focus on primary source documents and primary source excerpts.

Systematically study the interrelationships between diplomacy, armed conflicts, and utilization of the military in select examples from U.S. history.

Prerequisite Knowledge

The module is designed to introduce students to the dominant view regarding war-making authority of the delegates to the 1787 Constitutional Convention and how the document reflects those views. The assumption is that students will have little to no prior knowledge or understanding of the constitutional process of declaring war. Basic understanding of historical documents that influenced the development of the Constitution and the failure of the Articles of the Confederation, necessitating the Philadelphia Convention, is assumed, since this content is taught earlier in U.S. history courses.

Section One: Formal and Informal War Making in American History/Eighteenth-Century European Warfare and the Constitutional Convention


The objective of this introduction is to have students think reflectively about the war-making powers of government. When I’ve used this introduction, most of my students, for various reasons, do not know that the Constitution gives Congress the power to declare war.

Instructors should introduce the topic by using these questions or similar ones:

According the U.S. Constitution, which branch of government has the power to declare war?

When was the last time the United States declared war as directed in the Constitution?

Have students share their answers and discuss what they know about the constitutional directive. It is important that the instructor provide correct answers, especially noting that Article 1, Section 8 of the Constitution gives Congress the power to declare war, before moving forward. In order to fully frame the context of much of the rest of the module, students should also be made aware that Article 2, Section 2 of the Constitution designates the president as the commander in chief of the nation’s military.

Have students access the U.S. Senate website below or display it on a whiteboard. The site includes an easily understood chart of the eleven declarations of war passed by Congress:

https://www.senate.gov/pagelayout/history/h_multi_sections_and_teasers/WarDeclarationsbyCongress.htm (estimated time, fifteen minutes).

Eighteenth-Century Wars, Context, and Influences on the Founders

The following segment will help students better understand how eighteenth-century European warfare affected the Constitutional Convention delegates’ views of war and war-making authority. The Seven Years' War, better known as the French and Indian War in the U.S., is a particularly good example. It was a global war with a North American theater, and several delegates to the convention, including George Washington, were quite familiar with the war. Washington, president of the convention, had played an important role in touching off what would become the Seven Years' War.

This and other seventeenth- and eighteenth-century European wars made the American Founders quite concerned about the abilities of monarchs to unilaterally drag nations into serious armed conflicts. Students can access other examples of the scope and loss of life of eighteenth-century European wars in Appendix 1 of this module.

Anglo-French warfare was nearly constant throughout the eighteenth century.

Use the French and Indian/Seven Years' War to demonstrate the loss of blood and treasure associated with relentless Anglo-French warfare. Specifically review the scale and scope of the 1754–1763 Seven Years' War in Europe and America, which had an estimated 853,000 to 992,000 casualties. Instructors and students who prefer a quite succinct but accurate site on the Seven Years’ War (French and Indian War should access:


French and Indian War

French ships on fire off Quebec during the Battle of Quebec, September 13, 1759, in the French and Indian War. Source: British Battles at https://tinyurl.com/y79r42c2.

Discuss how the duration and death toll influenced the Founders to write what they did in the Constitution.

Students should be able to summarize the high cost in blood and treasure from eighteenth-century warfare after examining the Seven Years’ War case study. This enables them to better realize why the Founders wrote Article 1, Section 8 after debates about formal government war-making policies.

Use American historian Arthur Schlesinger’s quote as a transition to the next section on the Philadelphia Convention:

“With the war making propensity of absolute monarchs in mind, the framers took care to assign the vital foreign policy powers exclusively to Congress” (Schlesinger, 2004, 47)

(estimated time, ten to twenty minutes).

Enrichment/alternative Activity

Editor’s introduction: For a variety of reasons, the number of military history courses has precipitously declined in American colleges and universities in the past three decades. It is important for instructors and students to understand the value of learning military history. Classicist and syndicated columnist Victor Davis Hanson does a superb job of explaining why learning about war makes for a better understanding of history in "Why Study War?” from the summer 2007 City Journal.

Philadelphia Convention

Briefly discuss the context of the Philadelphia Convention of 1787—specifically why the delegates gathered in Philadelphia. Introduce or review the context of the Philadelphia 1787 Convention (e.g., the ineffectual Articles of Confederation, the Great Compromise-design of the national legislature, the three-fifths slavery compromise).

Discuss how and why (using the background of eighteenth-century bloodshed) the issue of the power to declare war was debated.

Display the following quotes from Philadelphia delegates on the screen or whiteboard and use them to facilitate a class discussion over the pros and cons of the legislative branch versus the executive branch retaining the power to declare war.

Pierce Butler (SC): “Vest the Executive with the power to take offensive military action” (9). (Inform students that Butler’s convention motion to vest war-making power in executive branch received no second).

Roger Sherman (CT): “The Executive should be able to repel but not to commence war” (9).

George Mason (VA) [argued] “against giving the power of war to the Executive, because not safely to be trusted with it” (9). 

Elbridge Gerry (MA) said he “never expected to hear in a republic a motion to empower the Executive alone to declare war.” He also noted the Constitution should not limit the executive from the power “to repel sudden attacks” (8).

(Above excerpts from Presidential War Power by Louis Fisher, 2004)

Questions for student discussion:

What are specific arguments for and against vesting the power to declare war in a chief executive?

What are specific arguments for and against vesting the power to declare war in the legislative branch? 

Summarize student discussion (collect student ideas on whiteboard) on the proper place for war powers.

Optional: Use the Picture of the Philadelphia Convention at: https://tinyurl.com/ya4u57xn as a segue into the actual language of the Constitution (estimated time, twenty minutes).

Constitution Convention

George Washington at the Philadelphia Convention. Source: What Would The Founders Think? at https://tinyurl.com/ya4u57xn.

Understanding War-Related Powers: The Constitution

The following brief overview utilizing the key passage in the Constitution should reinforce student understanding of the intent of the Constitution regarding Declaration of War.

Use the link or print copies of the Constitution to review Article 1, Section 8: http://www.annenbergclassroom.org/page/article-i-section-8.

Congress is vested with the power to declare war: The Congress shall have Power... To declare War, grant Letters of Marque and Reprisal (see Appendix 1), and make Rules concerning Captures on Land and Water.

Editor's note: Article 1, Section 8 also contains other war-related congressional powers included below.

To raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two Years;

To provide and maintain a Navy;

To make Rules for the Government and Regulation of the land and naval Forces; 

To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;

To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress (estimated time, fifteen minutes).

Section Two: The Mexican War and the War against Japan (Formal Declarations of War)

 Cerro Gordo

The Battle of Cerro Gordo during the Mexican War. Source: Descendants of Mexican War website at https://tinyurl.com/y7qzfa9a.

Section Two is designed to have students more closely examine the specific historical circumstances that led to two formal- declared U.S. wars.

Editor’s introduction: Because most students are likely to know little to nothing about events surrounding the Mexican War—and the fact that once basic knowledge is obtained, students can better understand the impact of this often-neglected war on the U.S. and North America—more comprehensive information is included in this segment of the module than is the case with the events that led to the December 8, 1941, Declaration of War against Japan.

U.S. Declaration of War, Mexican War (1846)

Students can access an accurate History Channel digital article that incorporates multimedia for a comprehensive homework introductory overview of the war at


Instructors can also use the following key points to provide students with contextual information concerning the events that precipitated the war.

The Mexican War (1846–1848) was the first war fought primarily outside the U.S. 

U.S.–Mexican relations had been strained ever since 1821, when Mexico won independence from Spain. Mexico was a republic in name only, and dictators, frequent revolutions, and unstable government were the norm. The U.S., France, and Great Britain frequently lodged claims against the Mexican government for damages to their nationals and property.

One of the issues of the U.S. 1844 presidential election was the American annexation of Texas—or “reannexation,” as President James K. Polk called it. Parts of what is now in the state of Texas were included in the original 1803 French sale of a vast amount of territory to the U.S. in the Louisiana Purchase that almost doubled the size of the U.S. but Spain, not France, owned most of what is now Texas.

After Mexico gained independence from Spain in 1821, the new nation welcomed American settlers into sparsely populated Texas.

Thousands of Americans flooded into Texas, and it became a republic in 1836, but the intent of most American settlers was for Texas to become an American state. Mexico never recognized Texas’s independence and made plans to recapture it when Congress annexed Texas March 3, 1845, the day before Polk became president.

Mexico recalled its minister and ended diplomatic relations with the U.S.; Polk sent American troops under the command of General Zachary Taylor into disputed areas of Texas to protect American lives and property. Mexico sent an army to the south bank of the Rio Grande, the alleged boundary of Texas that Americans had claimed since the early part of the 1800s.

American diplomatic efforts in Mexico City to negotiate a settlement of the Texas dispute and buy California and New Mexico failed. The pro-negotiation Mexican president was overthrown and replaced by an officer who promised to retake Texas and make diplomatic overtures to European powers to succeed.

Following the admission of Texas in December 1845 as a state, Polk ordered Taylor to move troops to the Rio Grande River. The Mexican Army received orders to cross the river and attack American forces, and two battles—Palo Alto and Resaca de la Palma, in the disputed territory north of the Rio Grande River—occurred in early May 1846.

On May 11, Polk, citing Mexico’s refusal to negotiate and accounts of American losses along the Rio Grande, asked Congress to declare war on Mexico. On May 13, the resolution passed with only token opposition.

The hard-fought war took place in-then Mexican territory but now American: New Mexico and California, as well as an American campaign further into Mexcio that resulted in the victorious occupation of the capital, Mexico City, on September 14, 1848. Almost 13,000 American military lost their lives in the war.

The treaty that ended the war was signed in early February 1848. Mexico ceded New Mexico and California to the U.S. and recognized the loss of Texas. The U.S. assumed the claims of Americans against Mexico and paid Mexico $15 million to help the nation achieve much-needed fiscal stability. 

The war, as Democrat Senator John C. Calhoun presciently predicted, increased sectional tensions because of the question of slavery in Texas. Some Whigs, including Illinois Congressman Abraham Lincoln, who considered the war immoral, unconstitutional, and pro-slavery, were opponents, as were the few abolitionists in Congress. However, most Americans supported the war because they believed it confirmed the superiority of democratic republics and the need to promote democracy far outside the boundaries of the U.S.

Supporters of the latter ideal included poet Walt Whitman and novelist James Fenimore Cooper.

Sources: Eric Foner and John A. Garraty, eds., The Reader’s Companion to American History, and http://www.history.com/topics/mexican-american-war.

Questions for student discussion:

Magazine editor, John L. O’Sullivan first used the term “Manifest Destiny” defined as the U.S. in an article on the U.S. annexation of Texas published in the summer of 1845: http://www.history.com/topics/manifest-destiny.

Believers in Manifest Destiny asserted that the U.S. should and was destined to stretch from coast to coast. Who do you think “destined” this national outcome? What does the term “manifest” mean? Students can learn more about the concept at the cited website.

After gaining independence from Spain, the Mexican government was often unstable and unable to protect Americans and Europeans who lived in Mexico or their property. The Mexican government promised to pay the U.S. government $2 million as compensation for damages but did not honor their commitment. Were these actions by the Mexican government reasonable grounds for U.S. military action? Why or why not?

Throughout U.S. history, a sentiment that surfaces and resurfaces strongly (and has substantial opposition as well) is the idea that freedom and democracy are the right of every human and it is the role of the U.S. to promote these values globally. Defend and/or critique these two assertions, using historical evidence in supporting or critiquing either position (estimated time, thirty to forty minutes). 

Enrichment/Alternative Activity

The Mexican War proved to be a training ground for some of the most prominent officers on both sides during the American Civil War. Students might wish to learn more about this topic by accessing the following link:


U.S. Declaration of War, World War II

After the 1868 internal revolution that ended the rule of shoguns in Japan, the U.S. and an industrializing and increasingly powerful Imperial Japan enjoyed generally cordial relations—until the early 1930s, when military officers displaced civilian politicians and assumed de facto and, at times, de jure control of the national government. The Japanese Empire, already controlling Taiwan and Korea, established a puppet government in Manchuria, started a 1937 war with China for control of that nation, and became a formal ally of Nazi Germany and Fascist Italy. In July 1941, tensions between Japan and the U.S. (as well as several Western European nations) escalated. The U.S., the Netherlands, and the U.K. economically punished Japan because of the empire’s expansionist policies that by 1940 included an incursion into French Indochina (now Vietnam). Japan was not allowed to purchase oil, steel, or military equipment, and Japanese assets in the U.S. were frozen. Japan continued diplomatic relations with the U.S. but secretly determined by fall 1941 that in order to acquire much-needed natural resources, Southeast Asia would be the next target, and this meant defeating Western powers, notably the U.S. and the U.K., in Asia. A surprise attack on American naval forces in Pearl Harbor in Hawaii with coordinated attacks in a few days on American and British forces in Asia was planned, and executed.

On December 8, 1941, President Franklin Delano Roosevelt addressed Congress and requested and received a declaration of war against Imperial Japan. Distribute copies or have students access the full text of the declaration request, which is available here: http://www.historyplace.com/speeches/fdr-infamy.htm The particular advantage of this link is that instructors have the option of having students read and listen to a radio broadcast of the speech that is easily utilized at The History Place site.

Instructors might also want to have students view a video clip of the speech to Congress, available on YouTube: http://youtu.be/YhtuMrMVJDk.

Reading or viewing the speech takes approximately seven to eight minutes, although teachers should encourage a more careful read. 

Both houses of Congress approved the declaration the same day, and only one Congresswoman, pacifist Representative Jeannette Rankin, voted against the war with Japan. Germany and Italy, honoring their treaty obligations to Japan, both declared war against the U.S. on December 11, and the U.S. Congress reciprocated by declarations of war against Japan’s two Axis allies.

Questions for student discussion:

Given what you know about the events that led to Pearl Harbor, did the U.S. have any other options regarding war with Japan? Please include a rationale for your position based on logic or evidence,

Now that you’ve reviewed two historical case studies where the U.S. has declared war utilizing constitutional procedures, can you think of any meaningful advantages of pursuing this course of action?

Reactions of students will vary when this topic is discussed, but many will most probably see no advantages. Instructors should encourage students to reconsider the question by accessing the following succinct argument for formal war declaration by historian David Kenneth, available at http://classroom.synonym.com/advantages-congress-declaring-war-7107.html (estimated time, thirty minutes).

Enrichment/Alternative Activity

Editor’s introduction: Often, students only learn about Pearl Harbor and Hiroshima in studying the Pacific Theater in World War II. The following short resources essay appeared in the fall 2015 issue (20, no. 2) of Education About Asia. Interested instructors and students can gain a much more comprehensive understanding of World War II in the Pacific through reading and accessing some or all sources in the essay.

Teaching About World War II in the Pacific: Recommended Resources

It is important for history students to learn about World War II in the Pacific. Haruko and Theodore Cook’s Japan at War: An Oral History (The New Press, 1992; reprint 2008) contains the accounts of sixty-eight men and women about their experiences in World War II. The book, which was published four years before the inaugural issue of Education About Asia, offers a balanced examination of highly readable stories about the war by Japanese (and Korean subjects of Imperial Japan), which will appeal to students.

A number of articles and essays about World War II in the Pacific have appeared in Education About Asia throughout the years. Michael A. Schneider’s “Pearl Harbor and Pan-Asianism: Teaching Ideology as History” assists students to understand the interplay between ideology and military action. Daniel A. Metraux’s “Teaching Pearl Harbor: A New Japanese Perspective” makes key insights of Japanese scholar Takeo Iguchi (“Demystifying Pearl Harbor: A New Japanese Perspective”) accessible to instructors and students. Military historian Eric Bergerud in “Japan, the US, and the Asian-Pacific War” provides an accurate description of the objectives of Japanese Imperial forces in World War II and dispels widespread but erroneous stereotypes about the Asia-Pacific Theater. Bergerud also includes a short but compelling description of the war in China, which is often overlooked in history classes. Yasuko Sato in “Pacific Heart of Darkness: Remembering World War II Combat Experiences” utilizes American and Japanese memoirs and film, all of which can be used in class to portray vivid and accurate impressions for students of what life was like for both sides. All four of these articles appeared in the winter 2012 issue (17, no. 3). Richard Rice’s “Thank God for the Atom Bomb?” and George P. Brown’s “Learning from Truman’s Decision: The Atomic Bomb and Japan’s Surrender” offer perspectives on the Hiroshima and Nagasaki bombings that differ on crucial points but accurately describe scholarly arguments for and against the American decision to use atomic weapons. The two articles appeared in the spring 2006 issue (11, no. 1). The EAA articles described here, as well as many more World War II-related articles and essays, including interviews with Pulitzer Prize-winning historians Herbert Bix and John Dower, are available in the online EAA archives at http://aas2.asian-studies.org/EAA/TOC/index.asp. 

Section Three: Key Cold War Policies—The Truman Doctrine, National Security Act of 1947, and NSC-68

Editor’s introduction: Instructors and students who need a broader context for understanding the Cold War should access Lucien Ellington’s “Teaching the Cold War: Economics, Ideology, and Morality” from The Foreign Policy Research Institute (October 2016).

U.S. foreign policy developed to counter Soviet expansion early in the Cold War. The Truman Doctrine became the foundation of American Cold War policy and led to the 1949 formation of the North Atlantic Treaty Organization (NATO), still an active military alliance.

The Truman Doctrine

President Harry S. Truman announced the plan to Congress early in 1947. A key statement in the Truman congressional message: “I believe 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. I believe that we must assist free peoples to work out their own destinies in their own way. I believe that our help should be primarily through economic and financial aid, which is essential to economic stability and orderly political processes.” 

Though not overtly stated, the Truman Doctrine implied that the U.S. would support nations threatened by Soviet Communism. Instructors or students interested in accessing the Truman speech can use this link: http://avalon.law.yale.edu/20th_century/trudoc.asp.

Historian Eric Foner (2008) contends the Truman Doctrine “set a precedent for American assistance to anticommunist regimes throughout the world, no matter how undemocratic, and for the creation of a set of global military alliances directed against the Soviet Union” (892).

In what specific ways did the Truman Doctrine expand U.S. international economic, diplomatic, and military power? (estimated time, ten minutes)

The National Security Act of 1947

The National Security Act of 1947 contained several changes to U.S. policy. One of the key components of the act was the creation of the Central Intelligence Agency (CIA). The CIA primarily focused on gathering foreign intelligence. This in turn increased the possibility of covert, including covert hostile, foreign actions.

For further information about the creation of the CIA, visit http://www.history.com/this-day-in-history/truman-signs-the-national-security-act.

Possible additional discussion topics on several additional elements of the National Security Act of 1947 are included in Appendix 1. (estimated time, ten minutes)

National Security Council Report 68 (NSC-68)

The document was a top secret-policy paper the National Security Council presented to Truman on April 14, 1950: National Security Council Report 68.

By 1950, the Soviet Union had unsuccessfully tried to block Western powers from access to Berlin, the USSR had successfully detonated a nuclear bomb, Korea had been split into two nations—one supported by the U.S. and the other by the USSR—and the largest nation in the world, China, had become a Communist nation.

Use the following quote to introduce NSC-68: “The issues that face us are momentous, involving the fulfillment or destruction not only of this Republic but of civilization itself” (NSC-68, para. 6). 

As a class, read page 4 of the PDF linked above, titled "Background of the Present World Crisis." (Note the first page 4 in the primary source link was voided—students should proceed to the next page.)

Have students summarize the section "Background of the Present World Crisis" and discuss how the post-World War II international climate affected the development of NSC-68. Focus on the significant changes in world order/power and the threat of nuclear war in this section of NSC-68.

Instructors can reference the following excerpts from NSC-68 in assisting students to understand the perspectives and policy recommendations of the authors of the report.

With the destruction of German and Japanese power and decline of Britain and France, dominant world power was now bipolar—between the U.S. and USSR.

The USSR’s top priority was establishing absolute power over the homeland and Eastern Europe.

Communism was a “new fanatic faith” that “seeks to impose its absolute authority over the rest of the world” (NSC-68, para. 4).

Conflict between the two superpowers was probable, and due to the growing number of nuclear weapons, everyone faced the threat of annihilation. 

Since Soviets relied on military power to advance their priorities, they could therefore be checked by U.S. military power. 

If this military power worked, then there was hope, because Soviets’ weak link was relations with the Soviet people who, once the U.S. showed it could contain and drive back Soviets, would foster internal seeds of destruction.

Suggested Questions and Discussion topics for students based upon key NSC-68 contentions.

How did containment work in a Cold War when both sides possessed atomic weapons?

How does it work in a post-Cold War world when nations with atomic weapons have opposing global interests?

Discuss the consequences of NSC-68. Based on assumptions in NSC-68, Secretary of State Dean Acheson favored:

A rapid, massive military buildup capable of defending the Western Hemisphere and essential Allied areas

Strengthening nascent alliances—NATO (April 1949) 

Creation of large-standing military to lessen reliance on nuclear weapons 

Providing and protecting mobilization bases

Conducting offensive operations to destroy vital elements of the Soviet war-making capacity

Defending and maintaining the lines of communication and bases areas necessary to the execution of the above tasks

The Cold War ended in 1991 with the internal collapse of the Communist government in Russia.

Culminating student discussion question:

Has this collapse resulted in contraction of the extensive U.S. diplomatic and military presence globally? Have students provide rationales for their answers

(estimated time, twenty minutes).

Section Four: Korean Conflict, an Undeclared War, 1950–1953

Truman Address

Truman addresses the nation on why the U.S. must intervene in the Korean War. Source: C-Span at http://tinyurl.com/yalo9cfk.

Enrichment/Alternative Activities

Editor’s introduction: Instructors and students who are interested in a comprehensive but succinct article on the Korean War should access James I. Matray’s article “The Korean War 101: Causes, Course, and Conclusion of the Conflict” from the winter 2012 issue (17, no. 3) of Education About Asia.

Instructors or students may also use this brief backgrounder on the creation of two Koreas and the Korean War, excerpted from Lucien Ellington and Tawni Ferrari’s “Why Do Some Nations Prosper? The Case of North and South Korea," from The Foreign Policy Research Institute, April 26, 2017.

As the war with Japan was ending, in August 1945, the U.S. State Department charged two American officers with the task of dividing the peninsula into an American and a Soviet occupation zone. They chose the 38th parallel. This decision gave control of Seoul to the Americans, and to everyone’s surprise, the Soviets agreed In 1948, under a United States–Soviet trusteeship, South and North Korea officially became two countries governed by two different political systems—the Republic of Korea (ROK) and the Democratic People’s Republic of Korea (DPRK), respectively.

War erupted on the peninsula only two years after country separation and less than five years after being released from Japan’s hostile grip. On June 25th, 1950, the Democratic People’s Republic of Korea, after assurances of Soviet and Chinese support, invaded the South. In reaction, with the Soviet member absent and unable to vote, the UN Security Council created an international force led by the U.S. to wage war against the North. At first, North Korean military forces were able to control most of the ROK, but a successful landing of U.S.-led UN forces at Inchon paved the way for a counterattack that destroyed most of the North Korean army and resulted in UN forces occupying much of North Korea. In November 1950, forces from the People’s Republic of China authorized by Mao Zedong intervened in the war and helped North Korea push U.S. forces south of the 38thparallel. The subsequent fighting over the next two years produced no decisive victor.

The Korean Armistice Agreement ended the Korean War on July 27, 1953. In an “Agreement between Commander-in-Chief of the United Nations Command, and the Supreme Commander of the Korean People’s Army and the Commander of the Chinese People’s Volunteers, the Korean Demilitarized Zone was established. This agreement created a two-kilometer buffer on each side of the 38th parallel. North of the buffer zone, the use of air, ground, and sea military support would be permitted under the leadership of Kim Il-sung on behalf of North Korea as long as the support was not deemed hostile. Likewise, in the South, similar military efforts could advance in tandem with efforts to govern democratically.

The Korean War devastated both economies. North Korea was the target of extensive aerial bombardment, and the South was engulfed by the land war. Additionally, Seoul, the capital of the South, changed hands four times as the opposing sides took and were then forced out of the city. Over one million people in the ROK alone were killed. According to estimates prepared for the United Nations, the devastation to the South Korean economy during the war years was approximately 3.03 billion USD, an amount almost equal to the combined value of all final goods and services the ROK produced in 1952 and 1953.

Chronology of Events leading to a U.S.-led UN Armed Response in Korea:

June 25th 1950 DPRK forces attack the ROK and President Truman refers matter to the UN Security Council (UNSC) who passes a resolution calling for a cease fire and DPRK withdrawal from the South.

June 27th and July 7th With the USSR, who had the power to veto a Security Council resolution, boycotting the UN because of American refusal to recognize the new Chinese Communist Government, the UNSC passes a resolution calling for a United Nations armed forces response and, in a July 7th resolution designated that the U.S. designate the commander of UN forces.

July 19th President Truman informed Congress, and later addressed the nation via radio and television regarding UN and U.S. military actions in Korea.

Instructors who wish to allocate time for all or some analyses of relevant primary source documents may access the following U.N. documents and accompanying video clip.

Link to UN Security Council Resolutions (UNSCR) 83, 84, and 85 (Designation of responsibility for relief of South Korean civilians to U.S. command in Korea)

Link: UN Security Council Resolutions 83, 84, 85

UNSCR 83 released June 27th 1950

Discuss the UNSCR recommendations and its implications for war

UNSCR 84 released July 7th 1950

Read UNSCR 84 and focus upon paragraphs three, four, and six.

Play at least the first three or four minutes of Truman addressing the nation on the Situation in Korea July 19th, 1950: https://tinyurl.com/ybrgoghk. Audio clip and transcript are the full speech (estimated time, twenty minutes).

U.S. Reaction to Invasion of South Korea (Estimated time 15 minutes)

Post the following quote on a whiteboard and have students read the excerpt:

President Truman stated, “Communism was acting in Korea, just as Hitler, Mussolini and the Japanese had ten, fifteen, and twenty years earlier. I felt certain that if South Korea was allowed to fall, Communist leaders would be emboldened to override nations closer to our own shores. If the Communists were permitted to force their way into the Republic of Korea without opposition from the free world, no small nation would have the courage to resist threat and aggression by stronger Communist neighbors.” (Ferrell, The Autobiography of Harry S. Truman. Boulder: University Press of Colorado, 1980.)

Use the quote and perhaps the video of Truman’s national address to discuss the U.S. position on Korea and how this position tended to confirm the tenants of NSC-68 addressed in Section Three of the module.

With the aforementioned U.N. resolutions and U.S. policies, did Truman actually seek congressional approval to declare war in Korea? (estimated time, fifteen minutes) 

Further Analysis of Truman’s Decision to Avoid a Declaration of War and Congressional Response

Excerpts from president’s news conference of June 29, 1950:

  1. Mr. President, could you elaborate on this statement that–I believe the direct quote was, “We are not at war.” And could we use that quote in quotes?

THE PRESIDENT. Yes, I will allow you to use that. We are not at war.

Question: Mr. President, would it be correct, against your explanation, to call this a police action under the United Nations?

THE PRESIDENT: Yes. That is exactly what it amounts to

From Teaching U.S. History, 2015, pars. 47-50.

Discuss how the president avoided a declaration of war per the Constitution

Truman described the conflict as a "police action" since it was an undeclared war

Police action was fought under the auspices of the United Nations and the UNSCR 84

Since Truman specifically stated we were “not at war,” congressional approval was not necessary

Despite the “police action” moniker, Truman committed U.S. troops in support of UNSCR 84 without consulting Congress (Fisher, 1997)

Congressional Response to the U.N. Resolution

Use congressional responses to conclude the section on Korea.

President Truman used the authority he believed the U.N. and the NATO treaty gave him as justifications for engaging in war in Korea without receiving the prior approval of Congress.

Senator Robert Taft (R-OH) did not support the use of U.S. forces in Korea and noted that when Congress ratified the U.N. charter “American troops would be committed to the UN only after a Special Military Agreement had been negotiated with the UN Security Council AND such agreement was approved by Congress.” Excerpts from Jacob Javits, Who Makes War, 1973.

The Senate Committee on Foreign Relations also noted (with respect to the U.S. joining NATO), “The treaty in no way affects the basic division of authority between the President and the Congress as defined in the Constitution. In particular, it does not increase, decrease, or change the power of the President as Commander in Chief of the armed forces or impair full authority of the Congress to declare war (Javits, p. 146).

Finally, Congress was concerned over the “growing power of the President to make undeclared war and the tendency of Congress to surrender is prerogative" (Javitz. 240)

Culminating Questions

In your opinion, did Truman exceed his constitutional authority in committing U.S. troops to a “war” without congressional approval? Why or why not?

Given the situation in Korea, if you indicated that Truman did exceed his constitutional authority, did the circumstances justify Truman’s decision? Why or why not?

What can we discern about Truman’s rationale to avoid a declaration of war? (estimated time, ten minutes)


Additional Information Eighteenth-Century Wars, Context, and Influences on the Founders

This can be assigned as homework to help students understand the scale and scope of eighteenth-century warfare or can be used in class as supplementary information as desired.

Additional examples of Anglo-French wars to be used if desired:

Anglo-French War (1702–1713)—part of War of the Spanish Succession

Anglo-French War (1740–1748)—part of the War of Austrian Secession

Anglo-French War (1778–1783)—linked to the American Revolutionary War

Note on Letters of Marque and Reprisal, excerpts from Presidential War Power by Louis Fisher (2004):

“Sovereigns were able to authorize private citizens to wage war on other countries”

“Quickly augment their armies and navies and respond more quickly and with greater force”

“Privately owned vessels were authorized to prey on foreign vessels and take plunder"

“The phrase ‘letters of marque and reprisal’ came to refer to any use of force short of war”        

Optional Activity: The National Security Act

Unified the nation’s military (which now included a separate Air Force) under a new Department of Defense.

Established the National Security Council (NSC) to coordinate between agencies and scrutinize intelligence.

Established the Central Intelligence Agency (CIA) replacing the post-war Central Intelligence Group—CIA was now a distinct agency for intelligence gathering and covert operations outside the U.S.

Contrasting areas of emphasis: CIA (external intelligence and security) versus the FBI (internal intelligence and security).

Questions for student discussion:

What did the National Security Act convey regarding emerging Cold War relationships between the USA and USSR?

What did the passage of the act, only two years removed from tenuous allies victorious in World War II, demonstrate about the lack of trust between the two superpowers—U.S. and USSR.

References and Resources

"A Report to the National Security Council - NSC 68. from The Truman Library." Here

http://www.britishbattles.com/war-of-the-revolution-1775-to-1783/: "American Revolutionary War." From British Battles. January 2017 

http://www.fpri.org/article/2016/10/teaching-cold-war-economics-ideology-morality/: Lucien Ellington’s “Teaching the Cold War: Economics, Ideology, and Morality.” from The Foreign Policy Research Institute (2016).

https://www.fpri.org/?p=19744: Lucien Ellington and Tawni Ferrarini’s “Why Do Some Nations Prosper? The Case of North and South Korea.” From The Foreign Policy Research Institute (2017).

Louis Fisher, Presidential War Power (Lawrence: University Press of Kansas, 2004).

Eric Foner and John A. Garraty, The Reader's Companion To American History (Boston: Houghton Mifflin, 1991).

Eric Foner, Give Me Liberty! An American History (New York: W. W. Norton & Company, 2008).

http://www.historyplace.com/speeches/fdr-infamy.htm:"Franklin D. Roosevelt for a Declaration of War” from the The History Place.

http://www.britishbattles.com/french-indian-war/: "French and Indian War” from British Battles. August 2016

https://www.city-journal.org/html/why-study-war-13029.html: Victor Davis Hanson’s.“Why Study War?” from the City Journal (2007).

Jacob Javits, Who Makes War: The President Versus Congress (New York: Morrow Publishing, 1973).

http://classroom.synonym.com/advantages-congress-declaring-war-7107.html: David Kenneth, "The Advantages of Congress Declaring War" from Classroom.

https://www.piratedocuments.com/american-schooner-1814-war-of-1812/: "Letter of Marque" from Pirate Documents

http://www.constitution.org/mil/lmr/lmr.htm: "Letters of Marque and Reprisal" from Constitution Society. December 28, 2007..

http://www.history.com/topics/manifest-destiny: "Manifest Destiny” from The History Channel. 2010.

http://aas2.asian-studies.org/EAA/EAA-Archives/17/3/1072.pdf : James I. Matray’s “The Korean War 101: Causes, Course, and Conclusion of the Conflict.” Education About Asia 17, no. 3 (2012)

https://www.thoughtco.com/generals-who-served-mexican-american-war-2136198: "Ten Civil War Generals Who Served in the Mexican-American War” from ThoughtCo. March 3, 2017.

http://tinyurl.com/n4gf2zk: "Official Declarations of War by Congress." from United States Senate.

http://avalon.law.yale.edu/20th_century/trudoc.asp: “President Harry S. Truman's Address Before A Joint Session Of Congress, March 12, 1947” from Yale Law Avalon Project 

https://www.c-span.org/video/?c4466278/truman-korea."President Truman's Korean War Address" from C-Span. September 2013.

http://unscr.com/en/resolutions/doc/84."Resolution 84" from the U.N. Security Council website

Arthur M. Schlesinger, War and the American Presidency (New York: W. W. Norton, 2005).

“Teaching About World War II in the Pacific: Recommended Resources.” (Editorial Side Bar excerpt) from Tal Tovy “From the Nisshin to the Musashi: The Military Career of Admiral Yamamoto Isoroku.” Education About Asia 20, no. 2, (2015): 49.

http://law2.umkc.edu/Faculty/projects/ftrials/conlaw/Constitution1787.html."The Constitution of 1787." from a University of Missouri at Kansas City Law School Faculty website. 


The President’s News Conference of June 29, 1950." Teaching American History. 2017.

http://www.history.com/topics/mexican-american-war: Mexican-American War.” History.com. 2009.

http://www.history.com/this-day-in-history/truman-signs-the-national-security-act: ruman signs the National Security Act. Retrieved from History.com. 2009.

Henry Truman and Robert Ferrell The Autobiography of Harry S. Truman (Boulder: University Press of Colorado, 1980)

http://www.annenbergclassroom.org/page/article-i-section-8: U.S. Constitution Article 1, Section 8” from Annenberg Classroom.

http://www.britishbattles.com/king-georges-war-austrian-succession/: "War of the Austrian Succession” from British Battles.

http://www.britishbattles.com/war-of-the-spanish-succession/: "War of the Spanish Succession” from British Battles.

http://necrometrics.com/warstatx.htm: Death Tolls for the Multicides of the Twentieth Century” from Necrometrics. October 2010.