As the coronavirus crisis unfolds, the United States military is taking on an increasingly important role. For good reason: The military brings specialized expertise in logistics and humanitarian assistance, possesses a deep culture of planning for emergencies and natural disasters, and has the staffing and resources to play a key supporting role in “combatting” the crisis. After all, the Department of Defense still remains the largest employer in the world. As of this writing, two U.S. Navy hospital ships are making preparations to deploy to support the coronavirus response and all 50 states and three territories have called over 9,000 National Guard men and women (and counting) to state active duty.

Yet core questions remain about what the military can do, can’t do, and should do to assist the federal, state, and local coronavirus response. How does a presidential emergency declaration impact the military’s legal authorities? What is the difference between the federal (“Title 10”) military and state (“Title 32”) National Guard? What are the legal implications of fully “federalizing” the National Guard? And does the use of the military domestically somehow undermine civil liberties and civilian control of the military?

In what follows, I answer these questions and others, highlighting 10 key principles to follow as policymakers seek to utilize the military in a manner that is innovative, responsive to the crisis, and consistent with the rule of law.

1.The three emergency declarations unlock access to resources, facilitating what the military can provide.

On March 13, President Donald Trump declared an emergency under both the National Emergencies Act and Stafford Act and issued a “major disaster” declaration for both New York and California. This follows the administration’s earlier declaration of a public health emergency under the Public Health Service Act. These emergencies open the door for resources to flow, as Alexandra Phelan and I have previously explained. Significantly, for the first time since the Stafford Act was passed in 1988, a “major disaster” was declared to address a pandemic, allowing additional military resources to be used in response. But what the military can and can’t do is fundamentally not impacted by these declarations; that is governed by the Posse Comitatus Act and other directives, discussed below.

 2. The Title 10 military (Army, Navy, Air Force, Marines) can and should play an important supporting role in the coronavirus crisis.

Defense Support to Civil Authorities is a core, critical mission within the military that allows the military to assist civilian authorities as they respond to the coronavirus crisis. Responding to “pandemic influenza and infectious disease response” falls into an already established category of Defense Support to Civil Authorities response, according to existing guidance and doctrine. For example, the DoD can build Army-style field hospitals adjacent to military hospitals, or deploy expeditionary military medical facilities. The Army Corps of Engineers and Navy Seabees, with their “can-do” attitude, should assist with this, and this is already in the works. And innovative ideas should be brought forward on how the military can best support civil authorities’ missions, while ensuring that state and local response personnel remain the face of the response and in the lead.

3. The Army and Air Force National Guards, while operating under state control, have broad legal authorities.

When state National Guard units are called to “state active duty,” they are operating under what is known as a “Title 32 status” (reflecting the applicable title in the U.S. Code) with a chain of command that flows from each state governor. This is the authority that U.S. governors are utilizing now and will be for the foreseeable future. National Guard personnel can assist with logistics, build medical facilities, and even assist in law enforcement operations. The state-controlled National Guard provides governors with maximum legal flexibility, which may prove valuable if a containment zone is established or a restriction on travel is put in place and states need additional resources to help with enforcement. For example, today in the nation’s capital, the National Guard is restricting access and enforcing social distancing in and around the crowded cherry blossom tourist area.

 4. As a legal matter, fully “federalizing” the National Guard limits what the National Guard can actually do.

Although we think of federal action during times of emergencies as expanding power and authorities to unleash resources, federalizing the National Guard paradoxically has the opposite result. If the federal government were to fully federalize the National Guard and place them under federal control, the chain of command and authorities would shift from the state governor (Title 32) to the president as Commander-in-Chief (Title 10). The Posse Comitatus Act’s limitations on domestic law enforcement (discussed below) by the military would, therefore, be implicated and the National Guard’s authorities would be more limited as a result. As of this writing, the federal government is paying for National Guard deployments in New York, California, and Washington state while keeping them under state control. This is both a wise legal and policy decision — see below.

5. As a policy matter, fully federalizing the National Guard to a Title 10 status creates further complications.

Adm. James “Sandy” Winnefeld (former vice chairman of the Joint Chiefs of Staff) and Gen. Craig McKinley (former chief of the National Guard Bureau) have strongly argued against bringing the National Guards currently under state active duty to a federal status. As a policy matter, they’re absolutely correct and are the nation’s experts in this matter. Governors know their states better than anyone, are in the best position to deliver aid, and have preexisting relationships with key players. Instead of federalizing the National Guard, the federal government should pick up the tab for the states’ increased National Guard coronavirus operations. Doing so would ensure that the National Guard stays under Title 32 state control but does not bankrupt the state. In 2010, Winnefeld and McKinley effectively solved this problem through the creation of a “dual-status commander” in each state. Thankfully, this relationship — where the federal government pays while the National Guard remains under state control — appears to be how the National Guard response to the coronavirus crisis is unfolding.

6. By statute, the federal (“Title 10”) Army and Air Force cannot play an active role in law enforcement.

Unfortunately, the rumor mill about the military imposing “martial law” or enforcing shelter-in-place restrictions is in full swing. This is such a concern that the head of the National Guard has had to address these unfounded conspiracy theories and FEMA actually has a website labeled “Coronavirus Rumor Control” to dispel such myths. Furthermore, the federal military is already restricted from playing an active role in law enforcement. This restriction stems from the 1878 Posse Comitatus Act. It states:

Whoever, except in cases and under circumstances authorized by the Constitution or Act of Congress willfully uses any part of the Army or the Air Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or imprisoned not more than two years, or both.

This is a Reconstruction-era criminal statute that restricts the Army (later amended to also include the Air Force) from playing an active role in domestic law enforcement matters. The statute’s odd name — “posse comitatus” — derives from the practice of sheriffs calling upon the Army to help perform law enforcement duties, particularly in Western states. Of note, the restriction on the federal military’s role in law enforcement matters is constrained by statute, not the Constitution’s text. So, Congress can waive the Posse Comitatus Act’s restrictions by another “Act of Congress.” More on that below.

7. By policy, the federal (“Title 10”) Navy and Marines cannot play an active role in domestic law enforcement matters.

The text of the Posse Comitatus Act makes no mention at all of the Navy or Marine Corps, which is somewhat surprising. The Department of Defense has placed what amounts to a legal straitjacket on the Navy and Marine Corps on law enforcement matters via a Department of Defense directive. This amounts to a policy prohibition, not a constitutional or statutory prohibition. In theory, the Department of Defense could unbind this self-imposed straitjacket on the Navy and Marine Corps, but it has been reluctant to do so for a variety of reasons. The upshot: All military assets under federal (“Title 10”) control are prohibited from directly participating in law enforcement activities — think of arrests, searches, and seizures.

Relatedly, the Posse Comitatus Act’s restrictions do not apply at all to the U.S. Coast Guard. Nor do they apply to the National Guard while operating under state status, as discussed earlier. This is often why you see the Coast Guard and National Guard playing such an important role in the aftermath of natural disasters. And you will hopefully continue to see the National Guard as the face of the military response throughout the coronavirus crisis.

8. Invoking the Insurrection Act would be a game-changer, but there appears to be little reason to do so.

The president could overcome the Posse Comitatus Act restrictions by using his authorities under the Insurrection Act. Doing so would obviate the Posse Comitatus Act’s restrictions on the military. Specifically, this law authorizes the president to use any part of the armed forces to enforce the law when:

[the] President considers that unlawful obstructions . . . assemblages, or rebellion against the authority of the United States make it impracticable to enforce the laws of the United States by the ordinary course of judicial proceedings, the President may call into Federal service the militia of any state and use the Federal military to enforce the laws . . .

The last time the Insurrection Act was invoked occurred in 1992 in the aftermath of the Los Angeles riots to impose law and order. While the Insurrection Act can invoke images of martial law, it has actually been successfully employed to protect the civil rights of minorities in the South during the 1950s and 1960s. It was perhaps most famously invoked by President Dwight Eisenhower in 1957 in Little Rock, Arkansas, to ensure the enrollment of African-American schoolchildren in the face of state defiance of a federal court order. Still, whether to invoke it or not is often a political calculus — it was not used, for example, in the aftermath of Hurricane Katrina at the request of the Louisiana governor.

Thankfully, there has so far not been a breakdown in civil order necessitating any serious discussion of the Act. Nevertheless, Steve Vladeck has hypothesized a scenario where interstate travel becomes more widely restricted and the president could turn to Insurrection Act authorities to assist local law enforcement in enforcing these measures.

9. The state-based National Guard should be the military’s face of the crisis.

The National Guard can play and should play a particularly critical role in this crisis. Furthermore, the federal military lack the same level of expertise and training in law enforcement matters as state National Guards. In sum, the military’s response should continue to remain one that is federally supported, state-managed, and locally executed.

10. Reserve military should strongly consider recalling Reserve doctors, nurses, medical specialists, and other key personnel.

It is critically important that the right people with the right expertise are on the frontlines of the coronavirus crisis, and that includes military personnel — but not if they are already doing important work in their communities. For example, there is likely no point pulling a doctor out of a community emergency room for Reserve military duty. Thankfully, Congress has recently updated the Defense Officer Promotion Act (DOPMA), which should facilitate recruitment of personnel with key skill sets and ease the transition from the Reserve to the active force for those men and women with specialized expertise.

As the coronavirus crisis unfolds, there will be increasing calls for the military to play a critical role. These 10 principles governing what the military can and should do in the face of this historic crisis should help get you started.

Image: Oregon Army National Guard Soldiers assisted the Oregon Health Authority (OHA) in setting up the Oregon Medical Station (OMS) at the Oregon State Fairgrounds, March 19, 2020. Photo by Sgt. 1st Class Zachary Holden/U.S. Army National Guard via Getty Images