The United States secretary of defense (SecDef) is the head of the United States Department of Defense, the executive department of the U.S. Armed Forces, and is a high-ranking member of the federal cabinet. The secretary of defense's position of command and authority over the military is second only to that of the president of the United States, who is the commander-in-chief. This position corresponds to what is generally known as a defense minister in many other countries. The secretary of defense is appointed by the president with the advice and consent of the Senate, and is by custom a member of the Cabinet and by law a member of the National Security Council.
The Joint Chiefs of Staff (JCS) is the body of the most senior uniformed leaders within the United States Department of Defense, which advises the president of the United States, the secretary of defense, the Homeland Security Council and the National Security Council on military matters. The composition of the Joint Chiefs of Staff is defined by statute and consists of a chairman (CJCS), a vice chairman (VJCS), the chiefs of the Army, Marine Corps, Navy, Air Force, Space Force, and the chief of the National Guard Bureau. Each of the individual service chiefs, outside their JCS obligations, works directly under the secretaries of their respective military departments, e.g. the secretary of the Army, the secretary of the Navy, and the secretary of the Air Force.
The chairman of the Joint Chiefs of Staff (CJCS) is the presiding officer of the Joint Chiefs of Staff (JCS). The chairman is the highest-ranking and most senior military officer in the United States Armed Forces and the principal military advisor to the president, the National Security Council, the Homeland Security Council, and the secretary of defense. While the chairman of the Joint Chiefs of Staff outranks all other commissioned officers, the chairman is prohibited by law from having operational command authority over the armed forces; however, the chairman assists the president and the secretary of defense in exercising their command functions.
The chief of staff of the Army (CSA) is a statutory position in the United States Army held by a general officer. As the highest-ranking officer assigned to serve in the Department of the Army, the chief is the principal military advisor and a deputy to the secretary of the Army. In a separate capacity, the CSA is a member of the Joint Chiefs of Staff and, thereby, a military advisor to the National Security Council, the secretary of defense, and the president of the United States. The CSA is typically the highest-ranking officer on active duty in the U.S. Army unless the chairman or the vice chairman of the Joint Chiefs of Staff are Army officers.
The Goldwater–Nichols Department of Defense Reorganization Act of October 4, 1986 made the most sweeping changes to the United States Department of Defense since the department was established in the National Security Act of 1947 by reworking the command structure of the U.S. military. It increased the powers of the chairman of the Joint Chiefs of Staff and implemented some of the suggestions from the Packard Commission, commissioned by President Reagan in 1985. Among other changes, Goldwater–Nichols streamlined the military chain of command, which now runs from the president through the secretary of defense directly to combatant commanders, bypassing the service chiefs. The service chiefs were assigned to an advisory role to the president and the secretary of defense, and given the responsibility for training and equipping personnel for the unified combatant commands.
The chief of staff of the Air Force is the service chief of the United States Air Force. They are the principal military advisor to the secretary of the Air Force on matter pertaining to the Air Force. They are a member of the Joint Chiefs of Staff, and thereby a military adviser to the National Security Council, the secretary of defense, and the President. The chief of staff is typically the highest-ranking officer on active duty in the Air Force, unless the chairman and/or the vice chairman of the Joint Chiefs of Staff are Air Force officers.
A unified combatant command, also referred to as a combatant command (CCMD), is a joint military command of the United States Department of Defense that is composed of units from two or more service branches of the United States Armed Forces, and conducts broad and continuing missions. There are currently 11 unified combatant commands, and each is established as the highest echelon of military commands, in order to provide effective command and control of all U.S. military forces, regardless of branch of service, during peace or during war time. Unified combatant commands are organized either on a geographical basis or on a functional basis, e.g., special operations, force projection, transport, and cybersecurity. Currently, seven combatant commands are designated as geographical, and four are designated as functional. Unified combatant commands are "joint" commands and have specific badges denoting their affiliation.
In the United States military, a general is the most senior general-grade officer; it is the highest achievable commissioned officer rank that may be attained in the United States Armed Forces, with exception of the Navy and Coast Guard, which have the equivalent rank of admiral instead. The official and formal insignia of "general" is defined by its four stars.
The United States Department of Defense is an executive branch department of the federal government of the United States charged with coordinating and supervising all agencies and functions of the U.S. government directly related to national security and the United States Armed Forces. As of June 2022, the U.S. Department of Defense is the largest employer in the world, with over 1.34 million active-duty service members, including soldiers, marines, sailors, airmen, and guardians. The Department of Defense also maintains over 778,000 National Guard and reservists, and over 747,000 civilians bringing the total to over 2.87 million employees. Headquartered at the Pentagon in Arlington County, Virginia, just outside Washington, D.C., the Department of Defense's stated mission is to provide "the military forces needed to deter war and ensure our nation's security".
Vice admiral is a three-star commissioned officer rank in the United States Navy, the United States Coast Guard, the United States Public Health Service Commissioned Corps, and the National Oceanic and Atmospheric Administration Commissioned Officer Corps, with the pay grade of O-9. Vice admiral ranks above rear admiral and below admiral. Vice admiral is equivalent to the rank of lieutenant general in the other uniformed services.
The senior enlisted advisor to the chairman of the Joint Chiefs of Staff (SEAC) is the most senior non-commissioned officer (NCO) position overall in the United States Armed Forces. The SEAC is appointed by the chairman of the Joint Chiefs of Staff to serve as a spokesperson to address the issues of enlisted personnel to the highest positions in the Department of Defense. As such, the SEAC is the primary enlisted advisor to the chairman, and serves at the pleasure of the secretary of defense. The SEAC's exact duties vary, depending on the chairman, though the SEAC generally devotes much of their time traveling throughout the Department of Defense, to observe training and communicating to service members and their families. The SEAC's normal term of assignment runs concurrently with the chairman, but an incumbent may be reappointed to serve longer. The first member to hold this post was William Gainey. The current SEAC is Troy E. Black, USMC who assumed the duties on 3 November 2023.
The chief of the National Guard Bureau (CNGB) is the highest-ranking officer of the National Guard and the head of the National Guard Bureau. The position is a statutory office, held by a federally recognized commissioned officer who has served at least 10 years of federally recognized active duty in the National Guard; the Army National Guard or the Air National Guard. In a separate capacity as a member of the Joint Chiefs of Staff, the chief is a military adviser to the National Security Council, the Homeland Security Council, the secretary of defense, and the president on matters pertaining to the National Guard.
The Chief of the United States Army Reserve (CAR) is the commanding officer of the United States Army Reserve, the reserve component of the United States Army. As the highest-ranking officer in the United States Army Reserve, the CAR is the principal advisor to the chief of staff of the Army on all matters relating to the Army Reserve, and is responsible for the personnel, operations and construction budgets of the Army Reserve, subject to the supervision and control of the secretary of the Army. Dual-hatted as Commanding General, United States Army Reserve Command, the CAR is also responsible to the Commanding General, United States Army Forces Command for the oversight of operationally-deployed Army Reserve forces.
The United States Department of Defense (DoD) has a complex organizational structure. It includes the Army, Navy, the Marine Corps, Air Force, Space Force, the Unified combatant commands, U.S. elements of multinational commands, as well as non-combat agencies such as the Defense Intelligence Agency and the National Security Agency. The DoD's annual budget was roughly US$496.1 billion in 2015. This figure is the base amount and does not include the $64.3 billion spent on "War/Non-War Supplementals". Including those items brings the total to $560.6 billion for 2015.
The vice chief of the National Guard Bureau (VCNGB) is the second highest-ranking officer of the National Guard Bureau, which is a joint activity of the United States Department of Defense. The vice chief is also the second in charge of the National Guard; which is a joint reserve component of the United States Army and the United States Air Force. The vice chief serves as the principal advisor to the chief of the National Guard Bureau and the secretary of defense, through the chairman of the Joint Chiefs of Staff, on matters involving non-federalized National Guard forces and on other matters as determined by the United States Secretary of Defense. The vice chief also serves as the principal adviser to the secretary of the Army, the secretary of the Air Force, the chief of staff of the Army, and the chief of staff of the Air Force, on matters relating to federalized forces of the United States National Guard and its sub-components; the Army National Guard, and the Air National Guard.
The chief of space operations (CSO) is the service chief of the United States Space Force. The CSO is the principal military adviser to the secretary of the Air Force for Space Force operations and, as a member of the Joint Chiefs of Staff, a military adviser to the National Security Council, the secretary of defense, and the president. The CSO is a statutory office held by a Space Force general, who is typically the highest-ranking officer on active duty in the Space Force.
