What the Joint Chiefs of Staff Do

The Joint Chiefs of Staff are among the most important leadership bodies in the U.S. military, yet their role is often misunderstood. They are not a battlefield command team issuing orders to troops in combat, nor are they a kind of “super-general staff” that runs the armed forces day to day. Instead, the Joint Chiefs serve as the nation’s top military advisers, helping guide the President, the Secretary of Defense, and the National Security Council on matters of war, readiness, strategy, and force structure. Their work sits at the crossroads of military expertise and civilian leadership, and their influence reaches into nearly every major defense decision the United States makes.

Who the Joint Chiefs Are

The Joint Chiefs of Staff are made up of the highest-ranking officers from each of the six military services: the Army, Navy, Air Force, Marine Corps, Space Force, and the Chief of the National Guard Bureau, who is a statutory member. The Chairman of the Joint Chiefs of Staff is the senior military officer in the United States, followed by the Vice Chairman. Each service chief brings the perspective, capabilities, and concerns of their branch to the table.

Historically, the Joint Chiefs emerged during World War II, when the United States needed a way to coordinate among the Army and Navy in large-scale global war. Over time, the structure evolved to include the Air Force after its creation in 1947, and later the Marine Corps and National Guard leadership in advisory roles. Today, the Joint Chiefs represent the collective military wisdom of the services, but they do not command combat forces directly. That distinction is central to understanding how the modern U.S. military works.

Their Main Job: Advising Civilian Leadership

At the heart of the Joint Chiefs’ mission is advice. The Constitution places ultimate authority over the military in civilian hands, with the President serving as Commander in Chief and the Secretary of Defense managing the Department of Defense. The Joint Chiefs provide expert military counsel to both leaders, helping them understand the risks, opportunities, and costs of different courses of action.

This advice can cover a wide range of issues. For example, the Joint Chiefs may assess whether the military is prepared for a crisis in Europe or the Indo-Pacific, whether a proposed operation has enough logistics support, or how a conflict could affect readiness elsewhere. They may recommend force structure changes, such as adding air defense units, expanding shipbuilding, or improving cyber capabilities. They also offer insight into training, personnel, and equipment needs across the services.

Importantly, the Joint Chiefs do not make policy. They help inform it. The President and Secretary of Defense decide what the United States will do; the Joint Chiefs explain what the military can and cannot do, and at what cost. In that sense, they are strategic advisers rather than operational commanders. Their value lies in their ability to combine experience from across the armed forces into a single, unified military perspective.

The Chairman’s Role and the Joint Staff

Among the Joint Chiefs, the Chairman holds a special place. While the Chairman is the senior military adviser to the President, Secretary of Defense, and National Security Council, he or she does not command the armed forces in the traditional sense. Instead, the Chairman coordinates the Joint Chiefs, represents them in high-level national security discussions, and helps ensure that military advice is coherent and integrated.

Supporting the Chairman is the Joint Staff, a group of officers and civilians drawn from all the services. The Joint Staff helps translate broad strategic guidance into analysis, planning, and coordination. This staff examines military options, prepares briefings, and works across service boundaries to improve interoperability. In modern warfare, where land, sea, air, space, and cyber domains often overlap, that joint perspective is essential.

The Chairman also plays an important role in communicating between the civilian leadership and the military services. If the Secretary of Defense needs a unified assessment of a crisis, the Chairman synthesizes inputs from the service chiefs and presents recommendations. If the President asks about the readiness of U.S. forces, the Chairman can provide a broad picture of the military’s capabilities. This makes the Chairman one of the most influential figures in national security, even without direct command authority over troops.

How Goldwater-Nichols Changed the System

The modern role of the Joint Chiefs cannot be understood without the Goldwater-Nichols Department of Defense Reorganization Act of 1986. This landmark law reshaped the U.S. military command structure and made the armed forces far more “joint” than before.

Before Goldwater-Nichols, the military services often operated as separate fiefdoms. The Army, Navy, Air Force, and Marine Corps sometimes competed for resources and influence, and coordination between them could be difficult. In combat operations, lines of authority were often confusing. Service chiefs had significant operational influence, and joint planning was not always smooth. The result, in some cases, was inefficiency and poor coordination.

Goldwater-Nichols addressed these problems by clarifying the chain of command and strengthening joint operations. One of its most important changes was to place the operational chain of command from the President to the Secretary of Defense to the unified combatant commanders, bypassing the Joint Chiefs and service chiefs for direct operational control. This means that the commanders of geographic and functional combatant commands—such as U.S. Central Command or U.S. Indo-Pacific Command—receive orders through this chain, not through the service chiefs.

The law also elevated the Chairman of the Joint Chiefs of Staff as the principal military adviser to the President and Secretary of Defense, reducing the tendency for competing service advice to dominate national decision-making. It encouraged officers to serve in joint assignments and made joint experience a key part of career advancement. Over time, this helped create a more integrated force, where Army, Navy, Air Force, Marine Corps, Space Force, and Guard personnel work together more effectively.

In practical terms, Gold