Defense Support of Civil Authorities, Updated

Before the Department of Defense can use an unmanned aerial system within the United States for domestic operations such as search and rescue missions or disaster response, specific authorization from the Secretary of Defense is necessary.

However, if DoD wants to use a UAS to help control domestic civil disturbances (such as a riot or insurrection), then further authorization from the President of the United State is required.

The patchwork of legal authorities and requirements for domestic military missions is presented in a newly updated DoD manual on Defense Support of Civil Authorities (DSCA).

Military support to civil authorities may be prompted by a variety of natural disasters and emergencies, including wildfires, earthquakes, floods, chemical, biological, radiological, and nuclear accidents or attacks, and — a new addition — cyber incidents. But such domestic missions have their own peculiar characteristics.

“Operations conducted by the US military in the homeland and US territories are very different from operations conducted overseas,” the DoD manual says, particularly since they are executed “under the authority and within the limitations of federal, state, and local laws.”

In particular, “For fear of military encroachment on civil authority and domestic governance, the PCA [Posse Comitatus Act] and policy limit DOD support to LEA [Law Enforcement Agencies],” the manual says.

More specifically, “DOD directives prohibit interdicting vehicles, searches and seizures, arrest, and similar activities (e.g., apprehension, stop, and frisk). Furthermore, engaging in questioning potential witnesses; using force or threats to do so, except in self-defense or defense of others; collecting evidence; forensic testing; and surveillance or pursuit of individuals or vehicles is prohibited.”

On the other hand, “the Insurrection Act permits the POTUS [President of the United States] to use armed forces under a limited set of specific circumstances and subject to certain limitations.”

(The President has used the authority under the Insurrection Act twice in recent history. In September 1989 the President ordered federal troops to the US Virgin Islands to restore order in the aftermath of Hurricane Hugo. In April 1992 the President ordered federal troops to restore order in Los Angeles during riots following the Rodney King verdict.)

The updated manual includes a new appendix presenting a matrix of domestic military missions along with the relevant approval authority and policy guidance.

For the first time, the manual includes “cyberspace-related incidents” among the circumstances that may trigger military involvement in domestic matters.

“Large-scale cyber incidents may overwhelm government and private-sector resources by disrupting the internet and taxing critical infrastructure information systems. Complications from disruptions of this magnitude may threaten lives, property, the economy, and national security…. State and local networks operating in a disrupted or degraded environment may require DOD assistance.”

See Multi-Service Tactics, Techniques, and Procedures for Defense Support of Civil Authorities (DSCA), Army, Marine Corps, Navy, Air Force, September 2015.

The authorized use of DoD unmanned aerial systems in domestic operations is described in Guidance for the Domestic Use of Unmanned Aircraft Systems, Policy Memorandum 15-002, February 17, 2015.