The US Constitutional and Legal Basis for a Declaration of War

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

Michael Breakey

Georgia Northwestern Technical College

Rome, Georgia


Clockwise, from top left: U.S. combat operations in Ia Drang, ARVN Rangers defending Saigon during the 1968 Tet Offensive, two A-4C Skyhawks after the Gulf of Tonkin incident, ARVN recapture Quảng Trị during the 1972 Easter Offensive, civilians fleeing the 1972 Battle of Quảng Trị, and burial of 300 victims of the 1968 Huế Massacre. Source: Wikipedia at

This module was developed and utilized in an introductory technical college U.S. history course but can be utilized in standard or honors-level high school history courses. It is the second module of a two-part series with the same title and can be used separately or in conjunction with all or a portion of Understanding the Complexities of War in American History: Select Case Studies, Part 1.

Estimated module length: Approximately three hours (excluding homework/ enrichment/supplemental activities)


Article 1, Section 8 of the U.S. Constitution grants the legislative branch the expressed power to declare war. Over the last 75 years, since the congressional declaration of war against Japan propelled the United States into World War II (although presidents in their capacity as commander and chief of the U.S. military informed Congress of their decisions to use military force and, at times, sought and obtained congressional approval for use of military force), the original constitutional process has not been followed. The U.S. has not formally declared war against an adversary since World War II, specifically June 4, 1942, against the Axis powers of Hungary, Romania, and Bulgaria. Three post-Korean War case studies that relate to U.S. initiation of military force—the Vietnam War, the 1973 War Powers Congressional Resolution, and the 1991 First Gulf War—are included in the module. The purpose of the module is not to influence students to either favor or oppose strict adherence to Article 1, Section 8 but to give them the basic knowledge to think more reflectively about both changes in the processes American presidents and Congress employ to use military force, as well as gain a better sense of the politics, diplomacy, and military considerations that have been prominent in more recent U.S. armed conflicts.


Students will:

Understand the Cold War Domino Theory and its relationship to the origins of the American war with Vietnam.

Understand the Tonkin Gulf Incident and subsequent congressional decisions to allow increased presidential power to use force.

Learn the context that led to President George H. W. Bush’s successful request to Congress for the use of force against Iraq in the 1991 first Gulf War.

Analyze the War Powers Act of 1973. Understand the rationale behind the act, the unintended consequences of the legislation, and that debates still occur in Congress today about the legislation’s ramifications for the U.S.

Discuss and debate the costs and benefits associated with increased executive power to commit U.S. troops to combat without seeking a formal declaration of war from Congress.

Systematically study the interrelationships between diplomacy, armed conflicts, and utilization of the military.

Prerequisite knowledge

Basic understanding of historical documents that influenced the development of the present Constitution is assumed, since this content is taught earlier in U.S. history courses. If students are not specifically familiar with Article 1, Section 8 of the Constitution, they should be assigned the introduction in Understanding the Complexities of War in American History, Part 1. Those instructors who are teaching post-World War II U.S. history might consider using sections three (Key Cold War Policies) and four (The Korean Conflict) either in class or for homework so that students might have a more comprehensive understanding of historical events relating to use of military force in the years after 1945.

Module Introduction: Who Has the Power to Declare War? (estimated time fifteen minutes)

If resources and activities from the first Complexities of War module are not utilized, provide students with a didactic, concise introduction that includes relevant constitutional statutes on the declaration of war.

Have students answer the following questions orally or in writing:

How does the congressional power to declare war work with or against the presidential responsibility as commander in chief?

(If applicable at this point, ask) Did the United States officially declare war against North Vietnam?

Have students share their answers and conjectures regarding the final listed questions.

Instructors should make students aware that Article 1, Section 8 has not been the process for American use of military force since 1945.

In order to provide context for the remainder of the content in this module, instructors should make sure students understand that Article 2 (or II), Section 2 of the Constitution designates the president as the commander in chief of the nation’s military).

Section One: Context for U.S. in Vietnam: Domino Theory (estimated time twenty minutes)

Introduce the Domino Theory to students by informing them that although there is some dispute over who first used the term “Domino Theory,” President Dwight Eisenhower used a variant of the term in a famous 1954 news conference in reference to the international advancement of Communism:

“Finally, you have broader considerations that might follow what you would call the ‘falling domino’ principle. You have a row of dominoes set up, you knock over the first one, and what will happen to the last one is the certainty that it will go over very quickly. So you could have a beginning of a disintegration that would have the most profound influences" (Eisenhower, 1954, p. 23).

Have students view the following four-minute, fifty-second basic introductory video clip, A Brief History of the Domino Theory, which explains the concept of the Domino Theory through exposition of the theory and illustrative summaries of how adherence to the theory among policymakers is an important explanation of U.S. policy actions in the Cold War, including Vietnam:

Immediately after they view the short video, have students in two to three sentences define Domino Theory and indicate how they think the concept influenced U.S. strategy in the Cold War in general and Vietnam in particular.

This introductory question provides instructors with the chance to clarify basic student understanding of the concept and the two historical events.

The U.S. in Vietnam (estimated time thirty minutes)

What follows are options for introducing students to the war and, more specifically the run-up to the August 1964 Gulf of Tonkin Resolution—when Congress granted President Lyndon Johnson administration permission to use substantial additional force (the American military was already providing assistance to the South Vietnamese government) in not only Vietnam but Southeast Asia to prevent Communist aggression.

Instructors can assign the following 2014 lecture as homework: National Security Strategy: The Vietnam War 1954–1975, by University of California–San Diego Professor Branislev Slantchev, The reading focuses on the U.S. in Vietnam, has the narrative power of a published article, and is a comprehensive overview complete with color maps and a timeline:

Some highlights from the Slantchev reading, organized chronologically, include:

The 1954 Geneva Accords formulated by nine nations and polities, after Ho Chi Minh’s Viet Minh had defeated the French who in the late 19th century colonized the territory that is now Vietnam. The Geneva conferees that included France, the U.S. The USSR, and two separate Vietnamese governments (one Communist, and the territory containing the remaining French forces) divided Vietnam at the 17th parallel. With the division of the country, Ho Chi Minh’s Communist Government, the Democratic Republic of Vietnam controlled North Vietnam and Emperor Bao Dai declared the southern portion of the country as the State of Vietnam. The 17th parallel division stipulated by the Geneva Conference was only meant as a temporary measure as national elections were to be held in 1956.

The U.S. and South Vietnam ignored 1954 agreements (no nations signed the Final Declaration-Encyclopedia Britannica) and the U.S Government worked to support a non-Communist government in South Vietnam through installing the Catholic anti-Communist Ngo Dinh Diem in the South. Diem took control of what was to become the Republic of Vietnam in a referendum vote in 1955.

Late in 1955, President Eisenhower deployed the Military Assistance Advisory Group to train South Vietnamese soldiers. U.S. involvement continued through the Eisenhower administration with Diem asking for increased U.S. support to fight Communist forces in the Republic of Vietnam.

In May 1961 President Kennedy sent 400 Special Forces to Vietnam to increase special operations training of South Vietnamese soldiers. In October 1962 the U.S. begins defoliation efforts (Operation Ranch Hand using Agent Orange) to deprive communist guerrilla fighters (Viet Cong) both food and cover.

Diem's harsh style of governing and favoritism of Catholic to Buddhist Vietnamese, along with the growth of political opposition to his regime undermined U.S. support. The Kennedy administration, aware of a potential coup, did not inform Diem. In November 1963, a military coup ousted Diem, who was assassinated. Just prior to his own death three weeks later, Kennedy increased U.S. military personnel in South Vietnam to 16,000. In the ensuing power struggles following the coup, Nguyen Van Thieu became president of South Vietnam in 1965.

The decisions to support various South Vietnamese leaders and increase U.S. troop strength were based on overall U.S. policy in the region. Slantchev describes early U.S. policy and rationale in Vietnam (p.7):

"Vietnam had become vital to US interests. Support of the South Vietnamese government was meant to defend against Communist expansion and reflected the concept of the domino theory."

American foreign policy analysts believed that the USSR was chastened by the Cuban crisis and thus would not directly intervene in Vietnam. China was believed to have withdrawn from the border with India due to the arrival of a US carrier force and American experts incorrectly concluded that China backed down because of the US threat/show of force.

“These conclusions dragged the US further into the Vietnamese conflict.” (Slantchev p. 7).

Discussion question: In what ways does the convergence of the Cold War, the Domino Theory, and the precedent of undeclared, presidential war in Korea affect U.S. involvement in Vietnam? 

Define “Vital National Interest” (estimated time ten minutes)

Review the concept of "vital national interest" with students.

National interest is defined as a “nation's perceived needs and aspirations in relation to its international environment. U.S. national interests determine our involvement in the rest of the world” (Yarger & Barber, 1997, p. 1).

Vital interest is defined as something that “if unfulfilled, will have immediate consequence for critical national interests” (Yarger & Barber, 1997, p. 2).

Have students discuss the meaning of vital national interest—what might be considered a vital national interest and how they understand/interpret the term. Put key points on board.

Ask students if they believe U.S. vital national interest was at stake in World War II and provide position rationales.

Ask students if they believe U.S. vital national interest was at stake in Vietnam. Summarize student answers before moving to the Gulf of Tonkin Incident. Instructors might want to ask the same question about Afghanistan if time permits.

The Gulf of Tonkin Incident (estimated time twenty-five minutes)

USS MaddoxTonkin Incident

The USS Maddox and a photo taken from it during the incident, showing three North Vietnamese motor torpedo boats. Source: Wikipedia at

Have the students watch the four-minute video on the Gulf of Tonkin Incident:

LBJ Signing 

President Lyndon B. Johnson signs the Gulf of Tonkin resolution. Source: U.S. National Archives

Use the link or the key points below to summarize Johnson’s response to the incident and his ambiguity:

Following the Gulf of Tonkin Incident, Johnson gathered congressional leaders and, without divulging specific details about what occurred off the coast of Vietnam, accused the North Vietnamese of open aggression on the high seas. Johnson submitted a resolution to both houses of Congress that authorized him to take “all necessary measures to repel any armed attack against the forces of the United States and to prevent further aggression” (Javits, 1973, p. 258).

The resolution was quickly approved by Congress, with only two dissenting votes, but after more information about the Tonkin incident became available, many in Congress concluded that Johnson and his advisers had misled them into supporting the expansion of the war.

Instructors might want students to watch as homework the video of Johnson’s address to the American public concerning the results of the Gulf of Tonkin Incident:

Note: Brief summaries of the Gulf of Tonkin Incident and U.S. escalation in Vietnam are available at the State Department’s website:

(This site asks for a user name and password but if the box is closed the site still appears)

Joint Resolution of Congress H.J. RES 1145 August 7, 1964—The Tonkin Gulf Resolution

Use the following link to the text of the Congressional resolution. Focus on the section starting with "resolved by the Senate and House of Representatives" and section three (bottom):

Instructors should follow up by asking why Congress approved the presidential use of military action?

Does the wording of “This resolution shall expire when the President shall determine that the peace and security of the area is reasonably assured” amount to a blank check for Johnson in conducting military action?

Does the Gulf of Tonkin Resolution run counter to the U.S. Constitution, specifically Article 1, Section 8? (estimated time, fifteen minutes)

Use this question for student discussion as a culminating in class discuss or as a short homework writing assignment:

What were the differences in the Gulf of Tonkin Incident as it occurred in contrast to how President Johnson described it to Congress and the American people?

Editor’s note: Vietnam and the Gulf of Tonkin Resolution Extension/Enrichment Activities

The extent that instructors might wish to teach or students might wish to learn about Vietnam could vary dramatically. Because of the potential interest in this war, several resources are included here. To date, the most critically acclaimed video history of the war is the twenty-three-part PBS documentary Vietnam: A Television History. Readers can access a 1983 New York Times review at:

Section Two: The Intended and Unintended Consequences of the 1973 War Powers Resolution (estimated time forty minutes for entire section)

Nixon Troops

President Nixon speaks with US combat infantrymen during the Vietnam War. Source: Business Insider at

Introduce the War Powers Act by having students read “Nixon and the War Powers Resolution,” available through the Bill of Rights Institute (BORI) at

This excellent teaching resource offers a succinct description of the context for the passage of the resolution, direct access to the primary source document, and follow-up questions. Allow time for students to read the narrative and the primary source document that are available at the above link. Delay having students discuss the questions or extension activities when they’ve completed the readings.

Then, introduce students to the following quotations concerning the War Powers Resolution:

“After decades of intense debate, congress passed legislation in 1973 in an effort to limit presidential war power” (Fisher, 2004, p. 144).

“The statute calls for the ‘collective judgment’ of congress and the president before committing troops to combat.” (Fisher, 2004, p. 145).

“The War Powers Resolution has had the effect of allowing the president to make war unilaterally for up to 90 days” (Fisher, 2004, p. 145).

After the above quotations are introduced, instructors might want to introduce students to the following summary of the key points of the War Powers Resolution, I utilized in my classroom:

First, in order to "insure that the collective judgment of both the congress and the president will apply to the introduction of United States Armed Forces into hostilities" the President's powers as commander in chief are exercised only pursuant to a declaration of war, specific statutory authorization from Congress, or a national emergency created by an attack upon the United States (50 USC Section 1541).

Second, it requires the President to consult with Congress before introducing U.S. forces into hostilities or situations where hostilities are imminent, and to continue consultations as long as U.S. armed forces remain in such situations (50 USC Section 1542).

Third, reporting requirements maintain that the president must comply any time he introduces U.S. armed forces into existing or imminent hostilities (50 USC Section 1543); Section 1543(a)(1) is particularly significant because it can trigger a sixty-day time limit on the use of U.S. forces under Section 1544(b).

Fourth, concerning congressional actions and procedures, Section 1544(b) requires that U.S. forces be withdrawn from hostilities within sixty days of the time a report is submitted or is required to be submitted under Section 1543(a)(1), with the following exceptions:

Unless Congress acts to approve continued military action

Is physically unable to meet as a result of an armed attack upon the United States

Section 1544(c) requires the president to remove U.S. armed forces engaged in hostilities "without a declaration of war or specific statutory authorization" at any time if Congress so directs by a concurrent resolution (50 USC 1544).

Instructors can choose (depending upon the time they have to allocate to the War Powers Resolution and their assessment of student understanding of Article 1, Section 8 of the Constitution) to refer students back to the Constitution’s language and to perspectives of a prominent architect of the Constitution, a well-known American historian, and a senator who was one of the authors of the War Powers Resolution.

Use the following material and quotes to set the discussion on the power to declare war: U.S. Constitution Article 1, Section 8.

Alexander Hamilton from Federalist 8: “It is the nature of war to increase the executive at the expense of legislative authority” (Hamilton, Madison, & Jay, 1961, p. 62).

American historian Arthur Schlesinger: “The chronic international crisis known as the Cold War at last gave presidents the opportunity for sustained exercise of almost royal prerogatives. What began as emergency powers temporarily confided to presidents soon hardened into authority claimed by presidents as constitutionally inherent in the office: thus, the imperial presidency” (p. 47).

One of the authors of the bill that would become the War Powers Act, Senator Jacob Javits: “The [war powers] bill I introduced…was designed to make sure that the democratic process protects us from one man decision making” (Javits, 1973, p. 268).

Constitutional Scholar Louis Fisher: “The War Powers Resolution is usually described as a concerted effort to ‘reassert’ congressional prerogatives. In fact, by recognizing that the President may use armed force for up to 90 days without seeking or obtaining legislative authority, the resolution legalizes a scope for independent presidential power that would have astonished the framers” (Fisher, 2004, p. 145).

Discussion Options

After (if time permits) considering the BORI reading, the War Powers Resolution primary source, and the related quotations, Instructors should have students discuss the BORI questions and extension suggestions that appear below or assign a short writing assignment based upon the questions:

How does the Constitution distribute war powers between the president and Congress, and why did the Founders decide on this arrangement?

What was the War Powers Resolution of 1973?

Why did President Richard Nixon veto it (Congress overrode the veto)?

Keeping in mind the constitutional war powers of Congress and the president, how would you assess the constitutionality of the War Powers Resolution?

Why do you think there has been no declared war since World War II, yet the U.S. has been almost constantly engaged in military action? What is the difference between Congress “authorizing the president to use force” and declaring war? Who bears more responsibility in each case? Which, if any, seems to lead to better outcomes for the U.S.?

Instructors are encouraged to conclude the discussion or have students in their written homework assignments if this options is used, to direct student attention to the BORI summation included below of the ongoing debate about the War Powers Act and getting final comments from the class.

Debate over the War Powers Act continues today. Critics want the law repealed for apparently contradictory constitutional reasons—some argue it takes too much power away from the President and gives too much to Congress, while others believe the President retains too much power at the expense of Congress. Have students work in groups to research arguments on both sides and answer the following questions:

What are the strongest arguments on each side?

How do the different arguments against the War Powers Act reveal different ways of interpreting the Constitution? 

Section Three: Conflict in the Persian Gulf Region: The 1991 First Gulf War (estimated time fifty minutes for entire section)

 George HW Bush

President George H. W. Bush. Source: at

Introduction: The Carter Doctrine

To understand U.S. involvement in the Gulf region, it is important to familiarize students with the Carter Doctrine. The Carter Doctrine was articulated in his January 23, 1980, State of the Union address. In it, President Jimmy Carter abandoned the policy of détente and reiterated the principle of the Truman Doctrine of containment but, in recognizance of the international geopolitics of energy resources, applied it in this case to deter possible USSR expansion in the Persian Gulf. 

Specifically, Carter (1980) stated: “Let our position be absolutely clear: An attempt by any outside force to gain control of the Persian Gulf region will be regarded as an assault on the vital interests of the United States of America, and such an assault will be repelled by any means necessary, including military force” (para. 27).

Link to full text of Carter’s State of the Union address:

Instructors can either succinctly summarize the events that led Carter to move away from détente or have them read the above summary and related paragraphs in the inauguration address and answer the following questions. 

Discussion Options

What precipitated the development of the Carter Doctrine?

What was another important factor that caused President Carter to mention the Persian Gulf region as being especially vital to U.S. interests?

Iraqi invasion of Kuwait and Military Buildup (Desert Shield)

In July 1990, Iraqi leader Saddam Hussein delivered a speech in which he accused the neighboring nation Kuwait of siphoning crude oil from the Ar-Rumaylah oil fields in southern Iraq, located along their common border. Moreover, Hussein insisted that Kuwait and Saudi Arabia cancel $30 billion of Iraq’s debt to both nations, primarily generated in the eight-year Iran-Iraq war (1980–1988). 

In August 1990, Hussein invaded Kuwait. Alarmed, two-thirds of the twenty-one members of the Arab League condemned Iraq’s act of aggression, and both Saudi Arabia’s King Fahd and Kuwait’s government-in-exile turned to the U.S. and other members of the North Atlantic Treaty Organization (NATO) for support.

In response, the U.N. Security Council (UNSC) condemned the invasion and drafted UNSCR 660 (August 2, 1990). In a second meeting about the situation in Kuwait, the UNSC again condemned the invasion and vowed to end the occupation with UNSCR 661 (August 6, 1990).

On August 8, 1990, President George H. W Bush, in an eleven-minute, eighteen-second speech to the nation, announced a buildup of American military personnel and equipment to defend Saudi Arabia from further Iraqi aggression. Have students listen to the speech and/or read the transcript at the following link: 

Despite mounting pressure, Hussein defied UNSC demands to withdraw from Kuwait by mid-January 1991.

Instructors may wish to assign as homework all or parts of . (Excerpts from this link appear above).

The Coalition

In response to Iraq ignoring UNSCR demands, the Bush administration successfully worked to build an international coalition made up of thirty-nine countries: Afghanistan, Argentina, Australia, Bahrain, Bangladesh, Belgium, Canada, Czechoslovakia, Denmark, Egypt, France, Germany, Greece, Honduras, Hungary, Italy, Kuwait, Morocco, the Netherlands, New Zealand, Niger, Norway, Oman, Pakistan, Poland, Portugal, Qatar, Saudi Arabia, Senegal, Sierra Leone, Singapore, South Korea, Spain, Sweden, Syria, Turkey, the United Kingdom, the United Arab Emirates, and the United States (CNN). While not all allies supplied both troops and equipment, ultimately the coalition numbered 670,000 troops from twenty-eight countries. About 425,000 of the troops deployed in Desert Shield were from the U.S. (CNN). With the coalition in place and the UNSCR deadline to leave Kuwait expired, Operation Desert Storm commenced January 17, 1991, and lasted forty-two days. Students can watch t Bush’s two most critical war messages below.

Bush’s televised announcement of commencement of hostilities in a nine-minute, fifty-nine-second speech on January 16, 1991, at

Bush's televised six-minute, fifty-two-second speech announcing the end of the Gulf War February 27, 1991, at 

Presidential Deployment and Use of U.S. Forces

 Gulf War Troops

U.S. troops deployed during Operation Desert Shield. Source: Stars and Stripes at

Specific to U.S. involvement in Desert Storm, Bush had deployed over 500,000 U.S. troops to Saudi Arabia in the five months after the Iraqi invasion of Kuwait. The U.S. countermeasure, was named Operation Desert Shield. Bush announced this was a defensive measure but “made no effort to seek authority from Congress” (Fisher, 2004,169).

Instead, Bush sought to create a “multinational alliance and encouraged the Security Council to ‘authorize’ the use of military force” (Fisher, 2004, 169).

"I think in a lot of actions … there seemed to be efforts to get things wrapped up by the sixty-day limit" (Fisher, 2004, 145).

As the UNSC deadline loomed, Bush requested a congressional joint resolution on January 8, 1991, one week before the January 15 deadline issued to Iraq in UNSCR 678. In response, Congress authorized the use of U.S. military force in the Gulf War on January 14, 1991. The Joint Resolution to Authorize the Use of United States Armed Forces Against Iraq is available at

Questions for student discussion:

Did Bush exceed his authority in deploying troops to Saudi Arabia under Operation Desert Shield? Defend your position.

Was the congressional Use of Force Resolution sufficient to commit U.S. troops to combat? Defend your position.

Does U.N. support obviate the need for congressional approval to commit U.S. troops to combat? Defend your position.

Concluding Questions that may discussed orally or assigned as written homework:

Post the following questions and have the students spend a few minutes thinking about the answers. Have the class share their answers and discuss the why behind their answers. 

Do changes in technology (both communications and military weaponry) make the formal Constitutional War? 

Making Powers archaic and even dangerous to national security? Put another way, is time so precious that the laborious process of congressional declarations of war not sufficient to meet the current threats?

Does the president's inherent power of acting in defense of national security preclude the necessity of seeking congressional approval to declare war?

Does the Constitution need to be amended to meet the emerging threats of the twenty-first century?

Do the students know of any examples where the declaration of war was a fait accompli (something already done and beyond alteration)? 

Time permitting—is an act of terrorism an act of war?

References and Resources A video from the "Brief History Of…" series on YouTube on the Domino Theory used by the US Government through the Cold War. Video of President George H. W. Bush's August 8, 1990 address on Iraq's Invasion of Kuwait hosted by the University of Virginia Miller Center. Overview of the Korean War by Michael Barnes from History on the Net. Text of Article I, Section 8 of the U.S. Constitution from Annenberg Classroom. Text of 50 U.S. Code Chapter 33: War Powers Resolution available on the Legal Information Institute website. Transcript of President Eisenhower's 34th news conference on April 7, 1954 from The American Presidency Project.

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

Eric Foner, Give Me Liberty! An American History (New York: W. W. Norton & Company, 2008). Video of President George H. W. Bush's February 27, 1991 address on the end of the Gulf War hosted by the University of Virginia Miller Center. Video of George H. W. Bush's declaration of war against Iraq from January 16, 1991. Entry of the Gulf of Tonkin Resolution from Videos section of's entry on the Gulf of Tonkin Resolution.

Alexander Hamilton, James Madison, and John Jay, The Federalist Papers.

Jacob Javits, Who Makes War: The President Versus Congress (New York: Morrow, 1973). Text of President Carter's State of the Union Address from 1980 at the Jimmy Carter Presidential Library and Museum website. Press release from The White House during the George W. Bush administration, "Joint Resolution to Authorize the Use of United States Armed Forces Against Iraq," from October 2, 2002. Lesson plan “Nixon and the War Powers Resolution." from the Bill of Rights Institute. Entry on the Persian Gulf War from Video of President Lyndon B. Johnson's August 4, 1964 report on the Gulf of Tonkin incident hosted by the University of Virginia Miller Center.

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

Branislav Slantchev, National Security Strategy: The Vietnam War, 1954–1975 (San Diego: University of California, 2014). Brief entry on President Truman signing the National Security Act on July 26, 1947 from's "This Day in History" series. Text of Joint Resolution (The Tonkin Gulf Resolution), August 7, Department of State Bulletin, August 24, 1964 from the Pentagon Papers, Gravel Edition, Volume 3. President Harry S. Truman's Address Before A Joint Session Of Congress, March 12, 1947 (The Truman Doctrine) from the Yale Law School Avalon Project. Text of the 1990 UN Security Council Resolution 660 from The United Nations website. Text of the 1990 UN Security Council Resolution 661 from The United Nations website. Article "U.S. Involvement in the Vietnam War: the Gulf of Tonkin and Escalation, 1964" from the U.S. government Office of the Historian website. 

Richard Yarger and George F. Barber, "The U.S. Army War College Methodology for Determining Interests and Levels of Intensity." U. S. Army War College. 1997. 118–126. Clip of President Johnson's Report on the Gulf of Tonkin Incident, August 4, 1964 from The University of Virginia Miller Center YouTube page. Review of PBS’s Vietnam: A Television History from The New York Times