The separation of powers - War, defense, and foreign affairs powers

Learning Outcomes

After reading this article, you will be able to explain the division of war, defense, and foreign affairs powers between Congress and the President. You will understand the constitutional sources, the scope and limits of each branch’s authority, and how these powers interact in practice. You will be able to apply these principles to MBE-style questions, including recognizing common exam pitfalls.

MBE Syllabus

For MBE, you are required to understand how the Constitution allocates war, defense, and foreign affairs powers between Congress and the President. This includes the following revision points:

• Identify Congress’s powers relating to war, military regulation, and foreign affairs.
• Explain the President’s powers as commander-in-chief and in foreign relations.
• Distinguish between treaties and executive agreements, and their legal effects.
• Recognize the limits on both branches, including checks and balances and judicial review.
• Apply the separation of powers doctrine to scenarios involving military action, treaties, and foreign policy.

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. Which branch of government has the exclusive power to declare war under the U.S. Constitution?
   1. The President
   2. Congress
   3. The Supreme Court
   4. The Secretary of Defense
2. The President’s power as commander-in-chief allows the President to:
   1. Declare war without congressional approval
   2. Direct military operations and deploy U.S. forces
   3. Ratify treaties without the Senate
   4. Enact military appropriations
3. A valid treaty between the United States and another country requires:
   1. The President’s signature only
   2. Approval by a majority of the House of Representatives
   3. Approval by two-thirds of the Senate
   4. Approval by the Supreme Court
4. Congress’s power to limit the President’s military actions is primarily exercised by:
   1. The power to appoint generals
   2. The power of the purse (appropriations)
   3. The power to issue executive orders
   4. The power to grant pardons

Introduction

The U.S. Constitution divides war, defense, and foreign affairs powers between Congress and the President. This separation is designed to prevent the concentration of power and to ensure checks and balances in national security and international relations. Understanding these allocations and their limits is essential for the MBE.

Constitutional Sources of Power

The Constitution grants specific powers to both Congress and the President regarding war, defense, and foreign affairs.

Congressional Powers

Congress holds several key powers:

• The power to declare war (Art. I, §8, cl. 11)
• The power to raise and support armies and a navy (Art. I, §8, cls. 12–13)
• The power to regulate the armed forces (Art. I, §8, cl. 14)
• The power to provide for calling forth the militia (Art. I, §8, cl. 15)
• The power to regulate commerce with foreign nations (Art. I, §8, cl. 3)
• The power to approve treaties (Art. II, §2, cl. 2)

Key Term: Declare War Power
The authority of Congress to formally declare a state of war, which is exclusive to the legislative branch.

Presidential Powers

The President’s main powers include:

• Commander-in-Chief of the armed forces (Art. II, §2, cl. 1)
• The power to make treaties (with Senate approval) and receive ambassadors (Art. II, §2–3)
• The power to direct military operations and deploy U.S. forces

Key Term: Commander-in-Chief
The President’s constitutional role as head of the U.S. armed forces, allowing direction of military operations.

Key Term: Treaty Power
The President’s authority to negotiate treaties, which become binding federal law upon Senate ratification by a two-thirds vote.

Key Term: Executive Agreement
An international agreement made by the President that does not require Senate approval and is not equivalent to a treaty in legal status.

Division and Limits of War and Defense Powers

Congress’s Role

Congress alone can declare war. However, the President may direct military actions without a formal declaration, especially in emergencies or limited conflicts. Congress controls military funding and can limit or end military actions by refusing appropriations.

The President’s Role

The President, as commander-in-chief, directs military strategy and operations. The President may deploy troops and respond to attacks or emergencies, but cannot unilaterally declare war or appropriate funds.

Treaties and Executive Agreements

• Treaties require negotiation by the President and approval by two-thirds of the Senate. Once ratified, treaties have the same legal status as federal statutes.
• Executive agreements are made by the President alone or with minimal congressional involvement. They do not require Senate approval and are inferior to treaties and federal statutes in case of conflict.

Worked Example 1.1

Congress passes a statute authorizing the President to use military force abroad to protect U.S. citizens, but does not declare war. The President orders airstrikes in a foreign country under this statute. Is this action constitutional?

Answer: Yes. Congress may authorize the use of military force without a formal declaration of war. The President, as commander-in-chief, may direct military operations pursuant to such authorization.

Worked Example 1.2

The President signs a treaty with another country, but the Senate refuses to approve it by a two-thirds vote. Is the treaty binding on the United States?

Answer: No. A treaty negotiated by the President does not become binding federal law unless ratified by two-thirds of the Senate.

Worked Example 1.3

Congress passes a law requiring state legislatures to enact specific military regulations. Is this law constitutional?

Answer: No. Congress may not compel state legislatures to enact federal regulatory programs. Congress may regulate the armed forces directly, but cannot commandeer state legislative processes.

Checks and Balances

• Congress can limit the President’s military actions by controlling appropriations and passing laws regulating the armed forces.
• The President can veto congressional acts, but Congress can override a veto with a two-thirds majority.
• The Supreme Court may review the constitutionality of actions by either branch, but often treats war and foreign affairs issues as political questions not suitable for judicial resolution.

Exam Warning

On the MBE, do not confuse the President’s power to direct military operations with the power to declare war. Only Congress can declare war, but the President may act as commander-in-chief without a formal declaration.

Revision Tip

Remember: Treaties require Senate approval; executive agreements do not. If a statute and a treaty conflict, the one adopted later in time prevails.

Key Point Checklist

This article has covered the following key knowledge points:

• Congress alone can declare war, raise and fund the military, and regulate armed forces.
• The President is commander-in-chief and directs military operations, but cannot declare war or appropriate funds.
• Treaties require negotiation by the President and approval by two-thirds of the Senate.
• Executive agreements do not require Senate approval and are subordinate to treaties and statutes.
• Congress may limit or end military actions by controlling appropriations.
• The Supreme Court may review actions, but often treats war and foreign affairs as political questions.
• Congress cannot force states to enact federal military regulations.

Key Terms and Concepts

• Declare War Power
• Commander-in-Chief
• Treaty Power
• Executive Agreement