The Commander in Chief Clause assures that there can be no military force beyond the president’s control. The military cannot be made an independent force (thus guaranteeing civilian authority over it), and it cannot be made to report to an entity other than the president (such as Congress, as under the Articles of Confederation). Further, as commander in chief, the president has authority over the deployment and operations of the military in peacetime, and over the conduct of military strategy, tactics and objectives once war has begun. In his discussion of the president’s powers in The Federalist No. 72, Hamilton observed that the “administration of government” falls “peculiarly within the province of the executive department.” That power includes the conduct of foreign affairs, the preparation of the budget, the expenditure of appropriated funds, and the direction of the military and “the operations of war.” As the Framers understood, success in the conduct of war demands the unique qualities of the president—unity, decisiveness, speed, secrecy, and energy.

Two substantial constitutional debates involve the Commander in Chief Clause. The first is whether the clause permits the president to initiate war without Congress’s approval. As discussed in connection with the Declare War Clause (Article I, Section 8, Clause 11), some scholars believe the president does have this independent power, while others believe that the Declare War Clause gives war-initiation power exclusively to Congress. As further noted in connection with the Declare War Clause, almost all scholars believe that the Commander in Chief Clause gives the president power to respond to attacks on the United States.

The second debate is the extent to which Congress can by statute or appropriations direct the way that the president controls the military. For example, Congress enacted or considered enacting statutes or restrictions on appropriations directing the president to take or refrain from taking specific actions in the War on Terrorism and in the conflict in Iraq. Congress of course has authority over the creation and supply of the military under Article I, Section 8—the legislature has no constitutional obligation to provide the weapons that the president wants to carry out his chosen war plans. It is less clear, however, whether and when Congress can intervene to compel the president to take particular actions regarding military operations. To some scholars, the president’s power under the Commander in Chief Clause is plenary, allowing no congressional intervention. Others believe that Congress’s various powers over war and the military allow a full range of congressional interventions—thus finding the president’s authority as commander in chief to be only residual, to be exercised in the absence of specific statutory direction. A third view holds that Congress has authority to restrict and direct the authority of the commander in chief in certain areas but not others.

Traditionally the courts treated decisions made by the president as commander in chief with great deference. Recent cases involving the War on Terrorism raised questions about the relationship between the commander in chief power and the courts. In Hamdi v. Rumsfeld (2004), the Supreme Court held that the writ of habeas corpus extended to the president’s decision to declare a U.S.-born detainee in the War on Terrorism an “enemy combatant.” Hamdan v. Rumsfeld (2006) found that the president’s unilateral creation of military commissions (specialized war crimes tribunals used in most major American wars) violated the Uniform Code of Military Justice enacted by Congress. In 2008, in Boumediene v. Bush, the Court held that habeas corpus extended even to non-citizen detainees held outside the United States at Guantanamo Bay, Cuba. In each case, strong dissents argued that the Court was interfering with the president’s traditional power as commander in chief.