The U.S. Armed Forces are one of the
largest military forces in terms of personnel. They draw their personnel from a large pool of professional
volunteers. Although military
conscription has been used in the past, it has not been used in the U.S. since 1973. The
Selective Service System retains the power to conscript males, and requires that all male citizens and residents residing in the U.S. between the ages of 18–25 register with the service.
United States Space Force was established as an independent service on 20 December 2019. It is the sixth branch of the U.S. military and the first new branch in 72 years. The origin of the Space Force can be traced back to the
Air Force Space Command, which was formed 1 September 1982 and was a
major command of the United States Air Force.
Presidential command over the U.S. Armed Forces is established in
Article II in the Constitution whereby the president is named as the "
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." The United States Armed Forces are split between two cabinet departments, with the
Department of Defense serving as the primary cabinet department for military affairs and the
Department of Homeland Security responsible for administering the
United States Coast Guard.
The military chain of command flows from the President of the United States to the secretary of defense (for services under the Defense Department) or secretary of homeland security (for services under the Department of Homeland Security), ensuring
civilian control of the military. Within the Department of Defense, the military departments (
Department of the Army,
United States Department of the Navy, and
Department of the Air Force) are civilian led entities that oversee the coequal military service branches organized within each department. The military departments and services are responsible for organizing, training, and equipping forces, with the actual chain of command flowing through the
unified combatant commands.
The U.S. Army is composed of the Regular Army,
United States Army Reserve, and
United States Army National Guard. The U.S. Army is organized into four army commands, which conduct the majority of the service's organize, train, and equip functions, ten Army service component commands, which command forces attached to the combatant commands, and twelve direct reporting units. The Army also organizes its personnel into 21 different
The U.S. Army's field structure is broken into several subdivisions under its commands:
Army group: Only used during large scale wars or as part of multinational commands, consist of four to five field armies and 400,000 to 1 million soldiers. Usually responsible for directing campaigns in a certain geographical area and commanded by a
Corps: Consists of two to five divisions and 20,000 to 45,000 soldiers commanded by a
lieutenant general. A corps is the highest level of command that provides operational direction for combat operations, with higher levels concerned with administration rather than operations.
Division: Consists of three to four brigades and 10,000 to 15,000 soldiers commanded by a
major general and are subdivided into
mountain divisions. Each division conducts major tactical operations and sustained battlefield operations.
Brigade / Regiment /
Group: Consists of two to three battalions and 3,000 to 5,000 soldiers commanded by a
colonel. Armored and
Ranger units are organized into regiments and
Special Forces are organized into groups. In 2016, the Army reorganized its brigades into
brigade combat teams, which are autonomous modular brigades that most commonly include one combat arms brigade and its assigned support and fire units.
Squadron: Consist of four to six companies and consist of up to 1,000 soldiers commanded by a
lieutenant colonel. Battalions are organized into combat arms battalions, combat support, and combat service support battalions by unit type. Armored and air cavalry are organized into squadrons. Battalions and squadrons conduct independent operations of limited scope and duration.
Troop: Consist of three to four platoons and a few dozen to 200 soldiers commanded by a
captain. Artillery is organized into batteries and armored and air cavalry units are organized into troops. Companies, batteries, and troops are tactical-sized units that can perform a battlefield function on its own.
The U.S. Marine Corps' Marine Air-Ground Task Force structure is broken into several levels under the Fleet Marine Force:
Marine Expeditionary Force: The largest type of Marine Air-Ground Task Force, consists of a marine division, air wing, and logistics group under a headquarters group and 20,000 to 90,000 marines and sailors commanded by a
lieutenant general. The principal warfighting organization of the Marine Corps during larger crisis or contingencies, MEFs' are self-sufficient for 60 days.
Marine Expeditionary Brigade: The medium type of Marine Air-Ground task Force, consists of a reinforced infantry regiment, reinforced composite marine aircraft group, and task organized logistics combat regiment under a command element and 20,000 marines and sailors commanded by a
brigadier general. Forward deployed MEUs provide an expeditionary force in readiness and are self-sufficient for 30 days.
Marine Expeditionary Unit: The light type of Marine Air-Ground task Force, consists of a reinforced infantry battalion, reinforced composite aviation squadron, and task organized combat logistics battalion command element and 2,600 marines and sailors commanded by a
colonel. Forward deployed MEUs provide an expeditionary force in readiness, capable of commencing missions on a six-hour timeline and are self-sufficient for 15 days.
The U.S. Marine Corps' unit structure is broken into several subdivisions under the Fleet Marine Force:
The U.S. Navy is composed of the Regular Navy and
United States Navy Reserve. The U.S. Navy is organized into eight navy component commands, which command operational forces, fifteen shore commands, which support the fleets' operating forces, five systems commands, which oversee the technical requirements of the Navy, and nine type commands, which administratively manage units of a certain type.
The U.S. Navy's unit structure is broken into several subdivisions under the type command structure. For Naval Air Forces:
Carrier air wing /
Wing: Consists of four strike fighter squadrons, one electronic attack squadron, one carrier airborne early warning squadron, on helicopter sea combat squadron, one helicopter maritime strike squadron, and one fleet logistic support squadron under the command of a
Wing: Consists of two or more groups commanded by a
brigadier general or
colonel. Wings typically contain an operations group, maintenance group, mission support group, and a medical group. There are two types of wings: composite wings or objective wings. Composite wings operate more than one kind of aircraft and may be designated as self-contained units designed for quick air intervention anywhere in the world. Objective wings are based on a single purpose, such as an operational, air base, or specialized mission.
Group: Consists of two or more squadrons whose mission are similar or complementary commanded by a
The Space Force's field structure is broken into several subdivisions under its field commands:
Garrison: Consists of two or more squadrons, or attached Air Force mission support and medical groups for garrisons and wings and a Space Force operations group for wings as well, commanded by a
brigadier general or
colonel. Deltas are responsible for executing a specific mission, while garrisons are responsible for installations support and management. Space Force wings are a legacy organizational structure inherited from the Air Force that manage a singular base and mission under one organization and are being phased out in favor of deltas and garrisons.
Unified combatant commands areas of responsibility
Unified combatant commands are joint military commands consisting of forces from multiple military departments, with their chain of command flowing from the president, to the secretary of defense, to the commanders of the combatant commands. There are eleven unified combatant commands that come in two types. Geographic commands, such as Africa, Central, European, Indo-Pacific, Northern, Southern and Space commands are responsible for planning and operations in a certain geographic area. Functional commands, such as Cyber, Special Operations, Strategic, and Transportation commands are responsible for a functional activity that crosses geographic boundaries. Each service organizes, trains, and equips forces that are then presented to the unified combatant commands through service component commands. Special Operations Command and Cyber Command also present theater special operations commands or joint force headquarters – cyber to other combatant commanders. Army or Marine Corps components are typically dual-hatted as the
joint force land component, Navy components are typically dual-hatted as the
joint force maritime component, and Air Force components are typically dual-hatted as the
joint force air component, with the theater special operations command dual-hatted as the joint force special operations component, and Space Force component typically dual-hatted as the joint force space component.
Global military expenditures by country for 2019, in US$ billions, according to SIPRI
The United States has the
world's largestmilitary budget. In the fiscal year 2019, $693 billion in funding were enacted for the DoD and for "Overseas Contingency Operations" in the War against Terrorism. Outside of direct DoD spending, the United States spends another $218 to $262 billion each year on other defense-related programs, such as Veterans Affairs, Homeland Security, nuclear weapons maintenance and DoD.
In FY2016 $146.9 billion was allocated for the Department of the Army, $168.8 billion for the Department of the Navy, $161.8 billion for the Department of the Air Force, and $102.8 billion for DoD-wide spending. By function, $138.6 billion was requested for personnel, $244.4 billion for operations and maintenance, $118.9 billion for procurement, $69.0 billion for research and development, $1.3 billion for revolving and management funds, $6.9 billion for military construction, and $1.3 billion for family housing.
While the United States Armed Forces is an all-volunteer military, conscription through the
Selective Service System can be enacted at the president's request and Congress' approval, with all males ages 18 through 25 who are living in the United States are required to register with the Selective Service. Although the constitutionality of registering only males for Selective Service was
challenged by federal district court in 2019, its legality was upheld by a federal appeals court in 2020.
As in most militaries, members of the U.S. Armed Forces hold a rank, either that of
warrant officer or
enlisted, to determine seniority and eligibility for promotion. Those who have served are known as
veterans. Rank names may be different between services, but they are matched to each other by their corresponding
paygrade. Officers who hold the same rank or paygrade are distinguished by their date of rank to determine seniority, while officers who serve in certain positions of office of importance set by law, outrank all other officers in active duty of the same rank and paygrade, regardless of their date of rank. In 2012, it was reported that only one in four persons in the United States of the proper age meet the moral, academic and physical standards for military service.
Rank in the United States Armed Forces is split into three distinct categories:
warrant officers, and
enlisted personnel. Officers are the leadership of the military, holding commissions from the president of the United States and confirmed to their rank by the
Senate. Warrant officers hold a warrant from the secretaries of the military departments, serving as specialist in certain military technologies and capabilities. Upon promotion to chief warrant officer 2, they gain a commission from the president of the United States. Enlisted personnel constitute the majority of the armed forces, serving as specialists and tactical-level leaders until they become senior non-commissioned officers or senior petty officers. Military ranks across the services can be compared by U.S. Uniformed Services pay grade or NATO rank code.
Officers are typically commissioned as second lieutenants or ensigns with a bachelor's degree after several years of training and education or
directly commissioning from civilian life into a specific specialty, such as a medical professional, lawyer, chaplain, or cyber specialist.
Warrant officers are specialists, accounting for only 8% of the officer corps. Warrant officers hold warrants from their service secretary and are specialists and experts in certain military technologies or capabilities. The lowest-ranking warrant officers serve under a warrant, but they receive commissions from the president upon promotion to chief warrant officer 2. They derive their authority from the same source as commissioned officers but remain specialists, in contrast to commissioned officers, who are generalists. There are no warrant officers in the Air Force or Space Force.
Warrant officers are typically non-commissioned officers before being selected, with the exception of the Army Aviation where any enlisted grade can apply for a warrant. Army Warrant officers attend the
Army Warrant Officer Candidate School.
Enlisted personnel consists of 82% of the armed forces, serving as specialists and tactical leaders. Enlisted personnel are divided into three categories:
E-1 to E-3/4: Junior enlisted personnel are usually in initial training or at their first assignment. E-1 to E-3 in the Marine Corps, Navy, and Coast Guard, and E-1 to E-4 in the Army, Air Force, and Space Force. In the Army, specialist (E-4) are considered to be junior enlisted, while corporals (E-4) are non-commissioned officers.
E-4/5 to E-6:
Non-commissioned officers in the Army, Marine Corps, Air Force, and Space Force and
petty officers in the Navy and Coast Guard. In the Air Force and Space Force, E-5 is the first non-commissioned officer rank. Non-commissioned officers and petty officers are responsible for tactical leadership.
All branches of the U.S. military enlisted women during World War II. The
Woman's Army Auxiliary Corps was established by the Army in 1942. Also formed during this time were the Women's Airforce Service Pilots (WASPs), the Navy's Women Accepted for Volunteer Emergency Services (WAVES), the Marine Corps Women's Reserve, and the Coast Guard Women's Reserve (SPARS). Women saw combat during World War II, first as nurses in the
Pearl Harbor attacks on 7 December 1941. In 1944, WACs arrived in the Pacific and in Normandy. During the war, 67 Army nurses and 16
Navy nurses were captured and spent three years as Japanese prisoners of war. There were 350,000 American women who served during World War II, and 16 were killed on duty. In total, they gained over 1,500 medals, citations, and commendations.
After World War II, demobilization led to the vast majority of serving women being returned to civilian life. Law 625,
The Women's Armed Services Act of 1948, was signed by
President Truman, allowing women to serve in the U.S. Armed Forces in fully integrated units during peace time, with only the WAC remaining a separate female unit. During the
Korean War of 1950–1953, many women served in the
Mobile Army Surgical Hospitals. During the
Vietnam War, 600 women served in the country as part of the Air Force, along with 500 members of the WAC and over 6,000 medical personnel and support staff. The
Ordnance Corps began accepting female missile technicians in 1974 and female crewmembers and officers were accepted into
Field Artillery missile units.
In 1974, the first six women naval aviators earned their wings as Navy pilots. The congressionally mandated prohibition on women in combat places limitations on the pilots' advancement, but at least two retired as captains. The 1991
Gulf War proved to be the pivotal time for the role of women in the U.S. Armed Forces to come to the attention of the world media; there are many reports of women engaging enemy forces during the conflict.
In 1991, women were permitted to fly military aircraft. Since 1994, women can serve on U.S. combat ships. In 2010, the ban on women serving on submarines was lifted.
On 3 December 2015, U.S. defense secretary Ashton Carter announced that all military combat positions would become available to women. This gave women access to the roughly 10% of military jobs which were previously closed off due to their combat nature. These restrictions were due in part to studies which stated that mixed gender units are less capable in combat. The decision gave military services time until January 2016 to provide plans on how they will enforce the policy change. Many women believe this will allow for them to improve their positions in the military, since most high-ranking officers start in combat positions. Since women are now available to work in any position in the military, female entry into
the draft has been proposed.
No woman has ever become a
Navy SEAL. However, in July 2021, the first woman graduated from the Naval Special Warfare (NSW) training program to become a Special Warfare Combatant craft Crewman (SWCC). The SWCC directly supports the SEALs and other commando units, and are experts in covert insertion and extraction special operation tactics.
Linda L. Fagan, the first female four-star admiral and first female Commandant of the Coast Guard
Despite concerns of a gender gap, all personnel, both men and women, at the same rank and time of service are compensated the same rate across all branches. On 1 June 2022, ADM
Linda L. Fagan assumed command of the
U.S. Coast Guard thus becoming the not only the first woman to serve as
Commandant of the Coast Guard but also the first woman in
American History to serve as a service chief in the U.S. Military.
A study conducted by the
RAND Corporation also suggests that women who make the military their career see an improved rate of promotion, as they climb through the military ranks at a faster rate.
As per the
Department of Defense’s report on
sexual assault within the U.S. Army for the fiscal year of 2019, 7,825 cases of sexual assault had been reported with the service members either victims or subjects of the assault. There has been a 3% increase in the number of cases as compared to the 2018 report.
As of 2021, there are 231,741 women in the military, representing 17.3% of the total active duty force. Since 2017, the percentage of women in active duty service has increased by 1.1%.
Order of precedence
Under Department of Defense regulation, the various components of the U.S. Armed Forces have a set order of seniority. Examples of the use of this system include the display of service flags, and placement of soldiers, marines, sailors, airmen, guardians, and coast guardsmen in formation.
While the U.S. Navy is older than the Marine Corps, the Marine Corps takes precedence due to previous inconsistencies in the Navy's birth date. The Marine Corps has recognized its observed birth date on a more consistent basis. The
Second Continental Congress is considered to have established the Navy on 13 October 1775 by authorizing the purchase of ships, but did not actually pass the
"Rules for the Regulation of the Navy of the United Colonies" until 27 November 1775. The Marine Corps was established by an act of the Second Continental Congress on 10 November 1775. The Navy did not officially recognize 13 October 1775 as its birth date until 1972, when then–
chief of naval operations Admiral
Elmo Zumwalt authorized it to be observed as such.
The Coast Guard is normally situated after the Space Force, however if it is moved to the Department of the Navy, then its place in the order of precedence changes to being situated after the Navy and before the Air Force.