What Does the U.S. National Guard Do?

What Does the U.S. National Guard Do?

The National Guard is a special part of the U.S. military that answers to both state governors and the president. While it began as a “strategic reserve,” the guard has come to play an important role in domestic and overseas operations.
A member of the National Guard patrols the southern U.S. border in Eagle Pass, Texas.
A member of the National Guard patrols the southern U.S. border in Eagle Pass, Texas. Brandon Bell/Getty Images
  • The National Guard is a unique branch of the U.S. military that has both state and federal responsibilities.
  • The guard routinely responds to domestic emergencies such as natural disasters and civil unrest, and it supports military operations overseas.
  • An intelligence leak by a National Guardsman in 2023 raised fresh concerns over the guard’s role in critical military functions, including surveillance and intelligence work.


The National Guard is an integral component of the U.S. armed forces, comprised of more than 430,000 civilian soldiers who are able to respond to both domestic crises and overseas conflicts. Over its nearly four-hundred-year history, the guard has transformed from a loose collection of colonial militias into a well-trained and equipped force that often serves side by side with active-duty military personnel. 

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The guard is also distinctive in that it serves under both state and federal command. It has been called upon in recent years to respond to many domestic events, including natural disasters, the COVID-19 pandemic, anti-racism protests, and border security challenges. As its domestic role has grown, the guard has also become more integral to international U.S. military operations. The Air National Guard in particular carries out critical military intelligence analysis, including in Ukraine and the Middle East.

What is the National Guard?

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Demonstrations and Protests

The National Guard is unique among the U.S. armed forces in that it can perform state and federal functions. The guard is generally called up to respond to state-level emergencies, such as natural disasters. But, unlike most of the other military forces, it can also serve a domestic law enforcement role. Additionally, the president can deploy the guard to serve missions overseas, which has happened more frequently in recent years, including to Afghanistan, Iraq, Poland, and the Horn of Africa.

The guard’s organization is somewhat unique. It consists of two parts: the Army National Guard and the Air National Guard, which are both considered U.S. military reserve components but are distinct from the army and air force reserves. The guard is overseen at the federal level by the National Guard Bureau, the head of which is a four-star general and member of the Joint Chiefs of Staff, the military’s top advisory body.  

As of fiscal year 2022, there were 434,689 guard members [PDF] in total, serving in fifty-four separate organizations across the fifty states; Washington, DC; and three U.S. territories: Guam, Puerto Rico, and the Virgin Islands.

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Many members of the National Guard serve part-time while holding civilian jobs or attending school. Guard members commit to one weekend of training per month plus a minimum of a few weeks of service per year. Most members serve in the states in which they live.

How did the Guard come about?

The National Guard traces its origins to the militias established by the American colonies. These militias grew out of the English tradition of organizing citizen-soldiers to provide for the common defense. The guard’s birthday is December 13, 1636, when the Massachusetts Bay Colony created the colonies’ first militia regiments. The state militias were preserved after the founding of the United States, reflecting the balance sought by the Constitution between state and federal authorities.

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However, it wasn’t until the early twentieth century, particularly after the passage of the 1903 Militia Act, and continuing through both World Wars, that the guard was transformed from a loosely organized network of militias into the well-equipped and regimented force it remains today. It was also during this period that the state-federal relationship became more defined.

Who controls it?

Most of the time, state National Guards are activated and commanded by the governors of their respective states or territories, but presidents (with input from top officials) can federalize the guard in certain cases. (The DC National Guard is solely under federal control.) For instance, presidents have called units into federal service to respond to extreme weather events such as hurricanes and wildfires, bolster border security, and assist U.S. military operations in Afghanistan and Iraq. Unlike state missions, which generally last less than three months, federal deployments tend to last at least a year. On international missions, the guard is often trained and commanded by active-duty military personnel, and their duties can be identical to their active-duty counterparts; however, hiring and other administrative tasks typically remain managed by state guard units. The National Guard can also be federalized but kept under state control, with the federal government paying for the deployment. (Statewide operations are normally funded by the state.) This was done in response to the COVID-19 pandemic in many states.

Presidents rarely federalize a state or territory’s guard without the consent of the governor. In the wake of Hurricane Katrina in 2005, President George W. Bush declined to take control of Louisiana’s National Guard due to the objection of Governor Kathleen Blanco. Governors have at times requested that the federal government assume control over their guard units, as California Governor Pete Wilson did during the 1992 Los Angeles riots.

Where does the National Guard deploy?

The National Guard fulfills a range of duties, including:

Disaster relief. The guard is frequently called up to respond to statewide emergencies, such as natural disasters. For example, more than one hundred thousand National Guard members were deployed to combat wildfires across nineteen states in 2022. The guard also prepares every year for the hurricanes that routinely strike the southeastern United States. In 2019, the guard responded to sixty-three natural disasters, including seven hurricanes or tropical storms, nineteen floods, and twelve fires. In 2023, members of the Hawaii Army National Guard were mobilized to support disaster response efforts after a massive wildfire on the island of Maui, Hawaii, including by ensuring public order and engaging in search and recovery missions.

Military support. The National Guard plays a crucial role in supporting U.S. military operations [PDF] abroad. Since 9/11, more than one million National Guard members have deployed to theaters including Afghanistan and Iraq, as well as countries in Europe and the Pacific. Most recently, the National Guard has helped collect and analyze intelligence related to Russia’s war in Ukraine and assisted in training members of Ukraine’s armed forces. Members of the guard have fought in nearly every U.S. conflict since the Revolutionary War, and more than twenty thousand are deployed around the world on any given day.

The Air National Guard in particular has played a growing role in military operations, especially in drone operations and data analysis. At some air force bases within the United States, members of the Air National Guard serve alongside active-duty personnel. 

Law enforcement. The guard can be deployed by state governors for law enforcement purposes. Many states activated their National Guards in response to historic anti-racism protests across the United States after Minneapolis police killed George Floyd in May 2020. In January 2021, the DC National Guard was deployed in response to an assault on the U.S. Capitol by a mob backing President Donald Trump while lawmakers were meeting to certify the presidential election. The guard was later quartered inside the Capitol building, evoking comparisons to the Civil War. In March 2024, in response to a surge in subway crime, New York Governor Kathy Hochul dispatched several hundred guard members to help police monitor the city’s busiest stations.

Border Security. The National Guard is part of the complex multiagency border security apparatus. As of May 2023, there were around 2,500 National Guard troops deployed to the U.S.-Mexico border. Some of these troops are on federal missions, directed by the president; others are run by states. At times, non-border states such as Florida and South Dakota have sent their own National Guards to the border. These troops primarily serve in an administrative capacity, with a directive against performing “law enforcement functions.”

Election support. The guard has provided cybersecurity support in recent years to state and local governments administering elections, including the 2020 presidential contest. Due to the pandemic, guard members performed additional election-related duties, including staffing polling places in some states (though in plain clothes to avoid the perception of military involvement in the political process).

State partnerships. The guard’s State Partnership Program (SPP) aims to increase state military-to-military relationships as a critical U.S. security cooperation tool. Administered by the National Guard Bureau, the SPP boasts partnerships with one hundred partner countries around the world. For example, the California Air National Guard’s partnership with Ukraine proved pivotal during the early stages of Russia’s invasion.

What controversies have there been over the Guard?

In a few instances, presidents and governors have clashed over the military’s domestic law enforcement role, particularly during periods of civil unrest. While governors can call on guard members to serve as temporary law enforcers, presidents cannot do so under normal circumstances. The Posse Comitatus Act generally prohibits the president from using the military in this role. However, presidents can circumvent this law by invoking the Insurrection Act. For example, President Dwight D. Eisenhower used the law to federalize the Arkansas National Guard to enforce desegregation of the state’s schools following the governor’s refusal to comply with the Supreme Court’s Brown v. Board of Education decision. President John F. Kennedy did the same in Alabama and Mississippi. 

Debate over the domestic use of the military flared once again in 2020 amid nationwide anti-racism protests sparked by Floyd’s death. President Trump threatened to deploy the military to quell civil unrest in parts of the country, and some Republican lawmakers urged him to do so using the Insurrection Act. Instead, he asked governors to send their National Guard troops to Washington, DC, to aid the federal response there, which was widely criticized as heavy-handed and legally murky. Trump also drew criticism for sending federal agents to several U.S. cities during the protests, including Portland, Oregon. Some Democratic lawmakers have suggested changing the law to prevent such an action.

By contrast, the response to rioters’ breach of the Capitol in January 2021 was criticized as slow and insufficient. Because Washington, DC, is not a state, the president or Pentagon must give the order for a guard deployment there. Then Acting Defense Secretary Christopher C. Miller ultimately deployed more than one thousand guard members, but some analysts questioned why they had not been positioned near the Capitol preemptively. Tens of thousands of additional guard troops were mobilized in the days following the attack to ensure a peaceful transition of power.

Meanwhile, at the border, National Guard deployments have been criticized for lacking the jurisdiction to implement U.S. immigration policy. Critics say poor working conditions for state deployments, including Texas’s so-called Operation Lone Star, have rendered them particularly ineffective. Others say such deployments are necessary to fill gaps in border patrol.

In April 2023, the Air National Guard’s expansive role in the military’s foreign surveillance and intelligence operations drew intense scrutiny after the FBI arrested a twenty-one-year-old guardsman for leaking highly classified documents. The disclosures contained top-secret information on the war in Ukraine and internal communications of U.S. partners Israel and South Korea. Critics, including some high-ranking U.S. lawmakers, called for reforms to the system for maintaining classified documents. Others questioned whether the National Guard should have access to critical military intelligence, except at the highest levels of the organization.

Recommended Resources

In I Am the Guard, Michael Doubler chronicles the nearly four-hundred-year history [PDF] of the Army National Guard.

For Just Security, Syracuse University’s William Banks looks at domestic use of the military and efforts to federalize the National Guard.

The Washington Post details President Trump’s controversial decision to deploy National Guard units in the nation’s capital in response to protests.

For the U.S. Marine Corps University’s Journal of Advanced Military Studies, Army National Guardsman Michael G. Anderson explains how balancing the guard’s domestic and overseas responsibilities is critical to preserving its sustainability.

The Congressional Research Service outlines the precedent [PDF] for deploying the National Guard to the southern U.S. border.

The Texas Tribune and Military Times examine Texas’s state-led National Guard deployment to the U.S.-Mexico border.

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Diana Roy contributed to this Backgrounder.

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