10 USC 113: Secretary of Defense Authority, Duties, and Limits

The Secretary of Defense’s powers and duties are set out primarily in 10 U.S.C. 113, which places the entire Department of Defense under the Secretary’s “authority, direction, and control,” subject only to the President. The job carries the broadest reach of any position in the defense establishment below the presidency: the Secretary sits in the operational chain of command to the combatant commanders, translates presidential policy into binding department directives, oversees the largest intelligence agencies in the federal government, and answers to Congress through a heavy schedule of required reports.

Who Can Hold the Job

The Secretary must be a civilian. The statute requires appointment “from civilian life,” and recent military officers face a mandatory waiting period. Officers below the grade of O-7 must wait at least seven years after leaving active duty; officers at O-7 or above must wait ten years.¹ Congress can waive those periods by statute and has done so on rare occasions, but the default rule reinforces civilian control of the military.

The President nominates a candidate, and the Senate must confirm. The Senate Armed Services Committee holds hearings, evaluates qualifications and policy positions, and votes on whether to send the nomination to the floor.²

Authority Over the Department

Once confirmed, the Secretary is the “principal assistant to the President in all matters relating to the Department of Defense,” with authority over every military department, defense agency, and field activity.³ The Secretary can delegate any function or duty to subordinates without giving up ultimate responsibility for the result.

That authority is not unchecked. Congress uses statutory mandates, oversight hearings, and the annual National Defense Authorization Act to set defense priorities and cap spending. The Secretary testifies regularly before the Senate and House Armed Services Committees and must comply with the reporting requirements those committees impose. Noncompliance can trigger funding restrictions or legislative changes to the Secretary’s authority.

Place in the Chain of Command

The operational chain of command runs from the President to the Secretary of Defense to the commanders of the combatant commands. Unless the President directs otherwise, every military order to a combatant command passes through the Secretary.⁴ The Secretary is not a bystander relaying presidential decisions. The office shapes how orders are executed, allocates resources among commands, and resolves conflicts between them.

The chain runs the same way for nuclear operations, from the President through the Secretary to U.S. Strategic Command. The Secretary’s role includes verifying that a presidential launch order is authentic before it is transmitted to the command for execution.⁴

Core Operational Duties

The Secretary turns presidential military policy into actionable plans for the Joint Chiefs of Staff, combatant commanders, and individual service branches. Department of Defense Directives establish binding rules across the armed forces on topics ranging from autonomous weapons systems to force modernization, and they carry the force of law within the department.

Special operations forces receive particular statutory attention. The Secretary oversees the United States Special Operations Command, whose commander is responsible for developing strategy, training special operations forces, and acquiring specialized equipment. The Secretary retains authority to direct which combatant command controls a particular special operations mission.⁵

The Space Force, established in 2019 as an armed force within the Department of the Air Force, sits under the Secretary’s authority in the same way as the other services. The statute explicitly extends the Secretary’s authority over the Air Force to the Space Force, its members, and its civilian employees.⁶

Intelligence Oversight

Several of the country’s largest intelligence agencies sit inside the Department of Defense, including the National Security Agency, the Defense Intelligence Agency, and the National Reconnaissance Office. The Secretary exercises authority over all of them through the Under Secretary of Defense for Intelligence and Security, who oversees policy, planning, and resource allocation for the Military Intelligence Program.⁷ The Under Secretary also handles functions the Secretary delegates under the National Security Act for the National Intelligence Program. The statute makes protection of privacy and civil liberties a “top priority” for the oversight role.

The Secretary must also report annually on special access programs, giving Congress cost estimates, milestone descriptions, and justification for each program’s classified status.⁸

Reporting to Congress

The Secretary must submit an annual written report to the President and Congress covering the department’s expenditures, work, and accomplishments. That report must include individual reports from each military department, an assessment of diversity and inclusion across the force, and an accounting of cost savings from eliminating duplication among the services.³

National Defense Strategy

Every four years, the Secretary delivers a National Defense Strategy to the congressional defense committees. When a new Secretary takes office after a presidential election, the strategy is due as soon as practicable after Senate confirmation. In off years, the Secretary must provide an interim assessment evaluating whether the current strategy needs revision.¹ The document covers ten required elements, including priority missions, the most critical threats to national security, force structure and readiness requirements, major investment plans for the next five years, and strategic goals for contested logistics and military installation resilience. Congressional committees use it to evaluate whether budget requests match strategic priorities.

Hostilities Reporting

When U.S. armed forces are deployed into hostilities or into situations where hostilities are imminent, the War Powers Resolution requires the President to notify Congress within 48 hours, describing the circumstances, the legal authority, and the estimated scope and duration of the involvement.⁹ That obligation runs to the President, but the Secretary’s office prepares the operational details and factual basis for the report, and the Secretary often delivers classified supplementary briefings to the defense committees.

Budget and Financial Accountability

The defense budget is the largest discretionary spending category in the federal government. For fiscal year 2026, the Department of Defense has roughly $1.43 trillion in budgetary resources, with approximately $882 billion in planned obligations.¹⁰ The Secretary justifies those expenditures before congressional appropriations committees, breaking spending down across personnel, weapons procurement, research and development, and readiness.

Financial accountability has been a persistent challenge. The department is working toward a clean audit opinion by fiscal year 2028 but has not received one despite years of effort.¹¹ The Under Secretary of Defense (Comptroller) maintains the Financial Improvement and Audit Remediation Plan, which tracks remediation milestones across the department’s financial systems.¹²

The Antideficiency Act adds personal legal exposure to financial discipline. Any officer or employee who spends more than Congress appropriated, or who authorizes obligations in advance of appropriations, faces suspension without pay, removal from office, or criminal penalties of up to $5,000 in fines and two years in prison.¹³

Enforcement Tools

The Secretary enforces compliance across active-duty service members, reserve forces, civilian employees, and private contractors, and different tools apply to each group.

Military Justice

Service members are subject to the Uniform Code of Military Justice, which sets criminal offenses and court-martial procedures across all branches worldwide. Military judges preside over courts-martial, but the Secretary shapes military justice policies and oversees the Judge Advocate General Corps. The UCMJ gives commanders at various levels the authority to bring charges, and the Secretary can influence prosecution priorities across the force.

Contractor Accountability

Defense contractors who violate their agreements face suspension, debarment, contract cancellation, or adverse personnel actions under federal procurement rules.¹⁴ The False Claims Act adds another layer: anyone who knowingly submits a fraudulent claim faces civil penalties of at least $5,000 per violation (adjusted for inflation), plus treble damages.¹⁵ The Defense Criminal Investigative Service works with the Department of Justice on those cases, and a single bid-rigging or fraudulent billing scheme can produce settlements in the millions.¹⁶

Whistleblower Appeals

Federal law prohibits retaliation against service members who report waste, fraud, or abuse. When a member files a complaint, the Inspector General investigates and submits findings to the Secretary of Defense and the relevant military department Secretary. If the investigation confirms a prohibited personnel action, the military department Secretary must correct the member’s record and report the corrective action taken. If the department Secretary declines to act, the member can appeal directly to the Secretary of Defense, who has 90 days to reverse or uphold the decision.¹⁷

Limits on the Job

Federal law sharply restricts the military’s involvement in domestic law enforcement. The Posse Comitatus Act makes it a criminal offense to use the Army, Navy, Marine Corps, Air Force, or Space Force to execute domestic laws, with violators facing up to two years in prison, unless Congress or the Constitution expressly authorizes an exception.¹⁸ Exceptions are narrow. The military can provide intelligence and logistical support for drug interdiction, for example, but cannot directly arrest or detain civilians. The Secretary manages this boundary whenever military assets are requested for domestic purposes.

Succession and Acting Secretaries

When the Secretary dies, resigns, or becomes unable to serve, the Deputy Secretary of Defense steps in and exercises all the Secretary’s powers. The Deputy must notify congressional leadership within 24 hours of any planned transfer of authority, or within 24 hours after an unplanned transfer.¹⁹ Executive Order 13533 sets a deeper line running through the Secretaries of the Army, Navy, and Air Force and then through Under Secretaries and other senior civilian officials, nearly 20 positions deep.

An acting Secretary who steps in under the Federal Vacancies Reform Act can serve for a maximum of 210 days from the date the vacancy occurs. If the President submits a nomination to the Senate, the acting official can continue serving while the nomination is pending. An action taken by someone who is not properly serving under these rules has no legal force and cannot be ratified after the fact.²⁰

1
Office of the Law Revision Counsel. 10 USC 113 – Secretary of Defense
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U.S. Senate. About Nominations
3
Office of the Law Revision Counsel. 10 USC 113 – Secretary of Defense
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Office of the Law Revision Counsel. 10 USC 162 – Combatant Commands Assigned Forces
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GovInfo. 10 USC 167 – Unified Combatant Command for Special Operations Forces
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Office of the Law Revision Counsel. 10 USC 9081 – The United States Space Force
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Office of the Law Revision Counsel. 10 USC 137 – Under Secretary of Defense for Intelligence and Security
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Office of the Law Revision Counsel. 10 USC 119 – Special Access Programs
9
Office of the Law Revision Counsel. 50 USC Chapter 33 – War Powers Resolution
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USAspending. Department of Defense (DOD) Spending Profile
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DoD Inspector General. Part 2 Understanding the Results of the Audit of the FY 2024 DoD Financial Statements
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Office of the Law Revision Counsel. 10 USC 240b – Financial Improvement and Audit Remediation Plan
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Office of the Law Revision Counsel. 31 USC Subchapter III – Limitations, Exceptions, and Penalties
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Office of the Law Revision Counsel. 41 USC 2105 – Penalties and Administrative Actions
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Office of the Law Revision Counsel. 31 USC 3729 – False Claims
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U.S. Department of Justice. Government Contractor Agrees to Pay 1M to Resolve False Claims Act Allegations for Submitting Fraudulent Bids on Prime Vendor Contracts
17
Office of the Law Revision Counsel. 10 USC 1034 – Protected Communications, Prohibition of Retaliatory Personnel Actions
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Office of the Law Revision Counsel. 18 USC 1385 – Use of Army, Navy, Marine Corps, Air Force, and Space Force
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Office of the Law Revision Counsel. 10 USC 132 – Deputy Secretary of Defense
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Office of the Law Revision Counsel. 5 USC Part III, Subpart B, Chapter 33, Subchapter III – Details, Vacancies, and Appointments