Commander-in-Chief Powers Under Article II

The commander-in-chief clause gives the president the sole power to conduct war and command the armed forces. However, only Congress can declare and fund wars, which has led to legal disputes regarding the extent of the president's war power.

As commander in chief, the president oversees the United States military and state militias when activated by Congress. Additionally, the president has the authority to issue executive orders and establish agencies to maintain the nation's operations and economic stability during times of war.

This article answers frequently asked questions and provides historical background about the commander-in-chief clause. 

Use the links below to jump to summaries of Supreme Court cases regarding commander-in-chief powers:

Where Does the U.S. Constitution Name the President Commander-in-Chief?

Article II, Section 2, Clause 1 of the U.S. Constitution defines the president's role as commander in chief. The commander-in-chief clause states:

The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States; he may require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any Subject relating to the Duties of their respective Offices, and he shall have Power to grant Reprieves and Pardons for Offences against the United States, except in Cases of Impeachment.

What Does "Commander-in-Chief" Mean?

The president's role as commander-in-chief means that the president is ultimately in charge of the United States military forces. When Congress declares war, the president has the final say in how to wage war. In the chain of command, they sit at the top of the hierarchy, and their orders are final.

Why Does the Constitution Give the President War Powers?

As a nation born out of the Revolutionary War, it may come as little surprise that the Framers gave the commander-in-chief power to the president. In fact, as the Framers debated the commander-in-chief clause, they already had someone in mind to fill the role.

During the Revolutionary War, General George Washington led the colonist's forces to victory over the British. The Second Continental Congress named Washington commander-in-chief in 1775, about one year after the American Revolution began.

Following the war, Washington realized the Articles of Confederation (the predecessor to the Constitution) did not serve the country well. In response, he helped assemble the Constitutional Convention in 1787. There, the Framers debated how to form a unified country out of the 13 colonies, which, at that time, acted more like independent nations than parts of a union.

The delegates elected Washington president of the Convention. The Framers had limited discussion or debate regarding the commander-in-chief clause. Observing Washington's leadership of the nation's armed forces and militias throughout the American Revolution, it seems the Framers conferred such powers upon the president for these reasons:

  • The Revolutionary War showed that vesting the country's war powers in one person allowed for efficient and quick responses during wartime. As Alexander Hamilton wrote in Federalist No. 69, the office "would amount to nothing more than the supreme command and direction of the Military and naval forces, as first general and admiral of the confederacy."

  • Vesting the power in a political leader responsible for (and accountable to) the country was better than vesting it in a different position. Because U.S. citizens elect the president, the citizens may elect a leader they believe will best run the military and protect the country.

At that time, there was perhaps no better candidate to assume the presidency and the title of commander-in-chief than George Washington. He had shown competence in leading the armed forces and restraint in using power wisely and in the nation's best interests. In a way, he embodied the role of commander-in-chief, and the Framers drew upon Washington's example when crafting the Clause.

In 1789, the Electoral College unanimously elected Washington as the first president of the United States. Many former military generals, including Andrew Jackson, Ulysses S. Grant, and Dwight D. Eisenhower, have become presidents. Of the 46 presidents, 31 have served in the military in some capacity.

What Are the War Powers Given to the Commander-in-Chief?

The text of Article II states that the commander-in-chief is in charge of the Army, Navy, and state militias once Congress declares war. Of course, the Air Force did not exist when the Framers created the Constitution, nor did the Coast Guard or Space Force. However, the president is ultimately in charge of each military branch.

The president's first duty is to protect the Constitution of the United States and ensure the country's national security. To do so, the president gives orders on how to wage war.

For all intents and purposes, the president is the “supreme commander” of the military. For example, the president is the sole person who can do (or delegate) the following:

  • Deploy troops

  • Invade a hostile country

  • Send spies into enemy territory

  • Drop nuclear bombs on the enemy

The clause, however, does not grant the president unlimited authority over war. While the president can wage war, Congress possesses multiple methods to influence the president's capacity to do so.

Limits on the Commander-in-Chief's War Powers

The Framers knew that creating a series of checks and balances between America's branches of government was essential. They limited the commander-in-chief's war powers by separating powers between the executive, legislative, and judicial branches.

Two of the most important limits on the commander-in-chief's powers include the following:

  • Only Congress (the House and the Senate) can declare war

  • Congress raises armies and funds the use of military force

The Constitution states that only Congress can make a declaration of war. Once it declares war, however, the president is the only person who can decide how to wage it. Even then, Congress controls how (and whether) to allocate funding for the war efforts.

These limits act as a strong check on the commander-in-chief's war powers. They have also resulted in tension and conflict between the legislative and executive branches.

Supreme Court Cases Regarding the Commander-in-Chief's War Powers

The conflicts between political branches regarding the war powers have led to landmark Supreme Court cases. These cases have defined the extent of the presidential power to command the armed forces. They have also lent credence to the theory of judicial supremacy over the legislative and executive branches.

Supreme Court jurisprudence regarding the commander-in-chief clause sheds light on its changes throughout United States history. As the nature of war and military operations have changed, so has the Court's interpretation of the executive branch's ability to wage war.

Since World War II, the president has generally obtained more power to wage war. More specifically, many military engagements post-World War II resulted from the president taking action and Congress responding to it afterward. The current state of the commander-in-chief's power essentially allows them to act as a unilateral decision-maker when it comes to military force.

This section provides a brief overview of some of the landmark decisions that have shaped the powers of the president into what they are today.

The Prize Cases

On April 12, 1861, Confederate troops attacked Fort Sumter in South Carolina. Most scholars point to the attack as the start of the Civil War.

But, President Abraham Lincoln did not call on Congress to declare war. Instead, soon after the attack, he ordered Union forces to blockade southern ports to disrupt the region’s economy. If the Union captured a ship violating the blockade, it could seize it as a "prize."

President Lincoln reasoned that his executive power allowed him to respond to the South's rebellion without congressional authorization because the conflict was not a "war" as defined by the Constitution. Part of his argument was that the Constitution does not allow Congress to declare war against another state. Because he did not recognize the South as a foreign enemy, he argued he did not need Congress's approval to respond to the rebellion.

A Northern owner of four ships seized by the Navy filed a lawsuit challenging the blockade's legality. Specifically, the owner argued that because Congress had not declared war against the South, the seizures amounted to piracy.

A divided Supreme Court upheld the blockade's legality in The Brig Amy Warwick. This opinion addressed several related cases known as the “Prize Cases.”

The Court held that the commander-in-chief can use the armed forces to combat invasions of foreign nations and suppress insurrections against a state or the federal government. The Court wrote that the president could "determine the degree of force the crisis demands," and he had a right to call for the blockade.

The Court also held that although Congress had not formally declared war against the South, the blockade conclusively showed that the Union was at war. It did not matter whether Congress had declared war because the South had begun the war by attacking Fort Sumter.

Because a state of war existed, the Court held the president could resist the South's force with the Union's force. Therefore, the president had the power to act by the right or law of war ("jure belli"). Plus, in 1861, Congress passed an act that approved and legalized the president's actions "as if they had been issued and done under the previous express authority and direction of the Congress..."

The Prize Cases represent an important interpretation and explanation of the president as commander-in-chief's powers. They delineated Congress's constitutional power to declare war and the president's constitutional authority to respond to attacks. They also clarified that the president has essentially the same power regarding using military force to fight an insurrection as they do to fight a foreign nation.

World War II

Three landmark cases concerning the commander-in-chief clause arose during World War II:

  • Hirabayashi v. United States (1943)

  • Korematsu v. United States (1944)

  • Ex parte Endo (1944)

In the wake of the attack on Pearl Harbor in 1941, President Franklin D. Roosevelt issued Executive Order 9066. It directed the military to exclude "any and all persons" from "military areas" on the West Coast. FDR also issued several orders establishing curfews on the West Coast.

FDR issued the orders for two primary reasons, both concerning national security. First, the government feared Japan was planning to attack the West Coast. Second, the government feared enemy spies would attack or weaken the United States from within.

The order did not direct military forces to detain any group in particular. But, in practice, it led to the military detaining over 110,000 people and placing them in internment camps. Most were Japanese Americans. The government also interned many German and Italian Americans.

Hirabayashi v. United States

Gordon Hirabayashi, an American citizen born to Japanese parents, disobeyed a curfew order that required anyone of Japanese descent to remain in their homes between 8:00 p.m. and 6:00 a.m. According to the government, the curfew was necessary to deter the potential for sabotage during WWII.

The government prosecuted and convicted Hirabayashi for violating the curfew. He appealed his conviction to the U.S. Supreme Court. The Court unanimously upheld his conviction. In the decision, the justices supported the commander-in-chief's judgment and military action during wartime. Notably, Chief Justice Stone wrote:

"Whatever views we may entertain regarding the loyalty to this country of the citizens of Japanese ancestry, we cannot reject as unfounded the judgment of the military authorities and of Congress that there were disloyal members of the population, whose number and strength could not be precisely and quickly ascertained. We cannot say that the war-making branches of the Government did not have ground for believing that in a critical hour such persons could not readily be isolated and separately dealt with, and constituted a menace to the national defense and safety, which demanded that prompt and adequate measures be taken to guard against it."

Fear and the reality of war led the Court to defer to the president and military's actions in Hirabayashi. In doing so, the Court deprived Japanese Americans of their physical liberty and freedom of movement and did so based on their identity rather than their actions. The ruling paved the way for another infamous decision one year later.

Korematsu v. United States

Fred Koramatsu was a Japanese-American living in California. The government arrested him in 1942 because he did not report to a relocation center. This defied the exclusion order issued by the president. The government convicted Koramatsu of violating the order.

He challenged his conviction in 1943, but the Supreme Court upheld it as constitutional in a 6-3 decision. Citing the "conditions of modern warfare," the Court declared that Order 9066 was necessary for national security. Once again, it deferred to the president and military action regarding potential military threats from Japan.

In a dissenting opinion, Justice Robert H. Jackson spelled out why he believed the Court should have overturned Korematsu’s conviction:

"Korematsu was born on our soil, of parents born in Japan. The Constitution makes him a citizen of the United States by nativity and a citizen of California by residence. No claim is made that he is not loyal to this country . . . Korematsu, however, has been convicted of an act not commonly a crime. It consists merely of being present in the state whereof he is a citizen, near the place where he was born, and where all his life he has lived."

Justice Jackson wrote further that the military orders the government based its conviction on were contradictory. One of the orders required Koramatsu to remain in his home, while the other required him to leave and report to an internment camp. Additionally, the only reason the orders applied to Korematsu was his status as a Japanese-American. As Justice Jackson wrote:

“Now, if any fundamental assumption underlies our system, it is that guilt is personal and not inheritable . . . But here is an attempt to make an otherwise innocent act a crime merely because the prisoner is the son of parents as to whom he had no choice, and belong to a race from which there is no way to resign.”

Justice Jackson contested the Court's majority opinion, which favored deferring to the president's authority and military action. He noted that the Korematsu opinion validated racial discrimination and set a dangerous precedent in doing so.

Korematsu is often noted as one of the worst Supreme Court cases, along with Dredd Scott v. Sandford and Plessy v. Ferguson. The Supreme Court effectively overturned Korematsu in 2018 with its decision in Trump v. Hawaii.

Ex Parte Endo

In Ex Parte Endo, decided on the same day as Korematsu, the Court ruled that the military did not have the authority to continue to hold Japanese Americans once they pledged or otherwise proved their loyalty to the United States.

The Court reasoned that any citizen who admitted they were loyal to the United States did not constitute a threat of espionage or sabotage. In essence, Endo ended the internment camps, as most of the people interned pledged loyalty to the United States. It was also important because it placed limits and pushed back against the president's authority as commander-in-chief.

Youngstown Sheet & Tube Co. v. Sawyer

Following World War II, the Supreme Court's jurisprudence regarding war powers continued to evolve. Perhaps most notably, the Court's 1952 decision in Youngstown Sheet & Tube Co. v. Sawyer pushed back on presidential authority during wartime.

In 1952, during the Korean War, President Harry S. Truman attempted to take control of private steel companies in the United States. Specifically, he ordered his Commerce Secretary Charles Sawyer to keep the steel mills running and to do whatever he could to avoid a potential nationwide labor strike. President Truman did this without congressional approval; he simply seized private steel mills.

The steel mill owners filed lawsuits challenging Truman's order. The case reached the Supreme Court, which held that Truman's order was unconstitutional. Specifically, the Court ruled that although the president may execute laws, he cannot make them; that's Congress's job.

Additionally, although the commander-in-chief clause allowed the president to command the nation's military, he could not seize private businesses to keep the war efforts on track.

Youngstown is significant because it drew a line in the sand regarding the president's powers under the commander-in-chief clause. After the World War II cases, it was important for the Court not to acquiesce to a president's constitutional overreach. That it happened not only during a war but also in response to Truman's claim that taking the steel mills was necessary set an important precedent.

Prosecuting War Criminals

Two Supreme Court cases involving war criminals and spies shed light on the president’s power to prosecute enemies and prevent terrorist attacks. These cases are important for a broader understanding of how the Court’s interpretation of the commander-in-chief clause has changed over time.

However, following the 9/11 terrorist attacks (explained below), the Court overturned one and has read another narrowly, thereby restricting the president’s war powers to prosecute war criminals.

Ex Parte Quirin

In Ex Parte Quirin (1942), the Supreme Court held that the president could use military tribunals instead of civilian criminal trials to prosecute war criminals. The case involved eight Nazi spies who had infiltrated the United States. They tried to blend in with the civilian population, all the while plotting attacks on Jewish-owned businesses and ways to disrupt the war effort. The FBI captured them after two of them turned on the other six.

President Roosevelt issued an executive order establishing military tribunals to deal with the spies. The order established that Roosevelt could review the tribunals’ judgments, and no court could review their judgments.

The spies’ attorneys filed a petition for habeas corpus during the military trial, challenging the legality of their detainment. Their petition also challenged whether the executive order was constitutional. Specifically, they argued that the process violated their Fourth and Fifth Amendment rights.

In a unanimous decision, the Supreme Court rejected the petition and determined that the executive order was constitutional. It held that the president could use tribunals rather than criminal courts to prosecute unlawful enemy combatants and doing so did not violate their rights.

Instead, only military courts had jurisdiction over alleged war crimes. The Court also noted that Congress had passed the Articles of War, allowing military tribunals to judge unlawful combatants.

In reaching its decision, the Court noted the difference between “lawful” and “unlawful” enemy combatants. Lawful combatants are, for example, soldiers on a battlefield. They wear uniforms, clearly identify themselves as “enemies,” and do not commit war crimes. When a lawful combatant is captured, they have a right to a trial in a civilian criminal court.

Unlawful combatants, on the other hand, do not wear uniforms, try to conceal their identities as enemies, and commit war crimes against civilians or prisoners of war. The Court ruled that unlawful combatants do not have a right to a criminal court trial because such courts do not have jurisdiction over war crimes.

The Nazi spies reached the United States via submarines. They brought explosives and identified potential targets. They also disguised themselves as American citizens. When they landed in the United States wearing uniforms, they were lawful enemy combatants. However, by disguising themselves among civilians, they had become unlawful enemy combatants (i.e., terrorists).

Therefore, the Court ruled that only a military tribunal had jurisdiction over them. Although the Court also held that such combatants had a right to file habeas corpus petitions, the Court ruled that the combatants had not shown cause to warrant a discharge.

Within days of the Supreme Court’s decision, authorities executed six of the eight spies. The two who had turned in their comrades spent years in prison until the U.S. deported them to Germany.

Johnson v. Eisentrager

The Supreme Court’s decision in Johnson v. Eisentrager (1950) built on the analysis in Quirin. There, the U.S. military captured German soldiers who helped the Japanese spy on China. The soldiers continued to fight the U.S. after Germany had surrendered. The U.S. military captured them, and a military tribunal convicted them in China. Then, the U.S. sent the soldiers to a U.S. facility in Germany.

While imprisoned in Germany, the soldiers petitioned U.S. District Courts for writs of habeas corpus challenging their confinement.

The Supreme Court ruled that civilian courts (i.e., civil and criminal courts) cannot interfere with the military’s detention of war criminals at an overseas military base. Nonresident alien enemy combatants do not have a right to habeas corpus, and civilian courts do not have appellate jurisdiction over military tribunals.

The Court relied upon the Alien Enemy Act of 1798, which allows the government to arrest and deport enemy aliens when the country is at war. The Court held that the Act prevents nonresident aliens from filing actions in U.S. courts during an ongoing war. The Court noted that the soldiers had never entered the United States, and the acts for which the tribunal convicted them occurred outside of the United States.

The Court also noted that if the U.S. allowed all prisoners of war to file petitions for writs of habeas corpus, enemies could use that to “hamper the war effort.”

A writ of habeas corpus generally requires the institution imprisoning the petitioner to present them to a court. In practice, this would create a right for prisoners of war in any theatre of war to appear in front of a court by filing a petition.

This, the Court noted, would place a serious burden on the military to transport any prisoner of war from faraway countries to bring them to court. This would divert the attention of field commanders from defeating enemies to instead providing them aid and comfort until they reached a U.S. court.

Both Quirin and Eisentrager clarified that the Constitution gave presidents the power to deal with war criminals as they see fit.

Because war criminals have allegedly broken the laws of war, the power to prosecute them falls under the commander-in-chief clause. As the Court noted in both cases, the commander-in-chief clause allows the president to punish war criminals via military authority, as opposed to a trial in front of an Article III court.

Post-9/11 Cases

On September 11, 2001, members of al-Qaeda hijacked four American airplanes and launched a series of attacks on the United States. The terrorists crashed two airplanes into the World Trade Center in New York City and one into the Pentagon in Washington, D.C. Passengers on Flight 93 fought back against the hijackers, causing them to crash in a field in Pennsylvania.

The terrorists killed approximately 3,000 people on 9/11. It was the largest terrorist attack on the United States since Pearl Harbor.

President George W. Bush responded to the attack by asking Congress to declare war on the terrorists. A week later, Congress passed the Authorization for Use of Military Force (AUMF). It authorized the president to use “all necessary and appropriate force” against any person, nation, or organization that aided al-Qaeda in the attack.

The AUMF gave President Bush broad discretion and authority to use any force and means he felt necessary to hold the terrorists accountable and prevent further terror attacks. Soon after, the War on Terror began.

Over the next several years, relying on the AUMF and Eisentragen, President Bush detained hundreds of alleged war criminals at Guantanamo Bay, a military base in Cuba. He also relied on Quirin to authorize military commissions to convict war criminals of war crimes

Several landmark Supreme Court cases arose during the War on Terror. The cases limited the president’s broad war power authority, gave constitutional rights to enemy combatants, and changed the meaning of the commander-in-chief clause.

Hamdi v. Rumsfeld

Hamdi v. Rumsfeld (2004) involved the military’s detention of an American citizen who fought with the Taliban against the United States.

Yaser Asam Hamdi was born in Louisiana, but his parents moved to Saudia Arabi when he was a child. As a young man, he joined the Taliban (an ally of al-Qaeda). In 2001, the U.S. military captured Hamdi in Afghanistan. The military initially imprisoned him at Guantanamo Bay.

Hamdi’s father filed a petition for a writ of habeas corpus, challenging the legality of his son’s confinement. When the government learned Hamdi was an American citizen, they transferred him to a military jail in Virginia, then South Carolina.

The Supreme Court held that because Hamdi fought against the United States as an enemy combatant, the president could detain him indefinitely. It did not matter whether or not the enemy was a U.S. citizen. The Court cited Quirin to uphold Hamdi’s detention.

However, the Court also held that an enemy combatant who was a U.S. citizen retained their due process rights under the Fifth Amendment. This meant that Hamdi had a right to challenge whether the military rightfully detained him. He also had a right to a hearing, although the Court did not specify the nature of said hearing.

In Hamdi, the Court cut against the president’s power to suspend enemy combatants’ constitutional rights and protections (for U.S. citizens, at least). It also clarified that enemy combatants who are U.S. citizens have a right to due process. Although the president may detain such combatants until the hostilities cease, they cannot deprive them of their constitutional rights.

Hamdan v. Rumsfeld

In Hamdan v. Rumsfeld (2006), the Court held that the president had no authority under the commander-in-chief clause or AUMF to create military tribunals to try and convict war criminals. Instead, Congress had to pass an act authorizing such tribunals.

The case involved Salim Ahmed Hamdan, a former bodyguard and chauffeur of Osama bin Laden. The military captured Hamdan and imprisoned him at Guantanamo Bay. 

Hamdan filed a petition for a writ of habeas corpus, relying on another case that allowed enemy combatants at Guantanamo Bay to do so. But before a court could consider it, a military tribunal designated him as a war criminal.

Several months later, a federal district court granted Hamdan’s petition for habeas corpus. The court ruled that before a military tribunal could designate him as a war criminal, the court had to hold a hearing on whether he was a prisoner of war. The district court relied on the Geneva Convention’s rules regarding the laws of war.

The D.C. Circuit Court of Appeals reversed the district court, holding that federal courts could not rely upon the Geneva Convention’s rules. The D.C. Circuit also found that Congress had authorized military tribunals.

The Supreme Court issued a writ of certiorari in the case. The Court held the following:

  • The president did not have the unilateral authority under the commander-in-chief clause to use military commissions to hold hearings and convict enemy combatants.

  • Congress had not expressly authorized the use of such military commissions.

  • Because the president did not have this power, and Congress had not authorized it, the military commissions had to use the “ordinary laws” of the United States and war (including the Geneva Convention’s rules).

  • Hamdan’s previous trial by military tribunal was illegal.

Hamdan is a significant decision for several reasons. First, it ensured that captured enemy combatants had constitutional rights. Second, it constrained the president’s war powers by declaring that the Constitution did not give them the authority to call for military tribunals unilaterally.

In response to the ruling, President Bush asked for congressional authorization to use military commissions. In 2006, Bush signed the Military Commissions Act of 2006 (MCA) into law. It authorized military tribunals to try enemy combatants for alleged war violations. The MCA also prevented enemy combatants from filing petitions for habeas corpus.

Boumediene v. Bush

In 2002, Bosnian police arrested Lahkdar Boumediene based on a suspicion that he intended to attack the U.S. embassy in Bosnia. The U.S. military ultimately transferred him to Guantanamo Bay. He filed a petition for a writ of habeas corpus. The courts initially dismissed his petition. At that time, enemy combatants held in overseas military bases could not file for habeas corpus.

Subsequently, the Court issued its opinion in Rasul v. Bush (2004). There, the Court held that enemy combatants had the right to file such petitions. The MCA, however, prevented federal courts from hearing his case.

The Supreme Court reviewed Boumediene’s case and held that enemy combatants held overseas had a constitutional right to file habeas corpus petitions. In doing so, the Court ruled that the MCA was unconstitutional because it violated the combatants’ rights.

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