Last week, the Inspector General (IG) of the Department of Defense (DOD) issued a report on the use of active duty troops to support Department of Homeland Security operations at the U.S. southern border. Several thousand active duty soldiers, or “Title 10 personnel,” have been at the border since 2018, when President Trump deployed them to guard against the supposed threat from a migrant caravan moving through Mexico. Under pressure from Congress, the IG announced a review of these troops’ presence late last year—including whether their use violates the Posse Comitatus Act, which bars federal military forces from engaging in law enforcement activities unless “expressly authorized” by Congress.

The IG’s report should raise alarm bells with those concerned about this administration’s domestic uses of the military. The report finds little evidence that federal troops have engaged in law enforcement at the border, but acknowledges that the White House purported to authorize such activities, and concludes that the authorization was consistent with federal law and not in violation of the Posse Comitatus Act. In reaching this conclusion, the IG dangerously misinterprets the law.

Misinterpreting Federal Law

The mission assigned to these troops, as set forth in a 2018 White House Decision Memorandum, encompasses “perform[ing] civilian law enforcement assistance, including a show of force, crowd control, temporary detention, and conducting cursory searches.” As the IG acknowledges, these are core law enforcement functions. Military involvement in such activities would violate the Posse Comitatus Act unless expressly authorized by Congress (I discuss the relationship between the Posse Comitatus Act and domestic deployment of the military more fully in a Brennan Center report on martial law released last week).

The IG cites two federal statutes – 10 U.S.C. § 274, which allows military forces to maintain and operate equipment in support of civilian law enforcement, and Section 1059 of the National Defense Authorization Act for Fiscal Year 2016, which grants DOD authority to assist Customs and Border Protection with border security – as authorizing Title 10 personnel “to provide direct and indirect civilian law enforcement assistance” in support of DHS operations at the southern border. Neither of these statutes, however, authorizes military participation in the law enforcement activities described by the 2018 Decision Memorandum.

Section 274 of Title 10 merely authorizes Department of Defense personnel to assist civilian law enforcement with “maintenance and operation of equipment;” it specifies activities such as performing “aerial reconnaissance” and operating equipment “to facilitate communications in connection with [certain] law enforcement programs.” Section 275 affirmatively prohibits reliance on Section 274 to authorize “direct participation by a member of the Army, Navy, Air Force, or Marine Corps in a search, seizure, arrest, or other similar activity unless participation in such activity by such member is otherwise authorized by law.” Indeed, the IG acknowledges in a footnote that 10 U.S.C. § 274 only authorizes DoD personnel to provide indirect assistance to law enforcement. It follows that this law cannot provide an exception to the Posse Comitatus Act.

Likewise, nothing in Section 1059 of the National Defense Authorization Act for Fiscal Year 2016 suggests that DOD personnel may directly participate in law enforcement. Subsection (c) provides an apparently exhaustive list of the types of assistance that the statute permits:

(1) Deployment of members and units of the regular and reserve components of the Armed Forces to the southern land border of the United States.

(2) Deployment of manned aircraft, unmanned aerial surveillance systems, and ground-based surveillance systems to support continuous surveillance of the southern land border of the United States.

(3) Intelligence analysis support.

Neither here nor anywhere else in the statute does it mention direct military involvement in law enforcement. Thus, it falls far short of the “express authorization” that is required to create an exception to the Posse Comitatus Act.

Overstating DOD Policy Guidance

It is not surprising, then, that the IG spends little time on these statutes beyond a few cursory references, and relies more heavily on DOD Instruction 3025.21. This is the only “federal law” the IG cites that purports to authorize direct military involvement in law enforcement activities.  Specifically, the IG refers to a provision in DODI 3025.21, Enclosure 3 that claims to allow “active participation in direct law-enforcement-type activities (e.g., search, seizure, and arrest)” as part of what the IG calls “force protection measures.” The IG goes on to say that the 2018 Decision Memorandum invoked this provision by authorizing DOD to deploy Title 10 personnel to “[protect] CBP and other U.S. Government personnel” at the border.

But this is misleading. The relevant section in DODI 3025.21, Enclosure 3 does not refer to “force protection measures.” It is far narrower, saying that direct participation in law enforcement by federal troops is allowed where necessary for the “protection of DoD personnel, equipment, and official guests” (emphasis mine). Thus, not even the DOD policy cited by the IG supports the kind of direct military involvement in law enforcement that the 2018 Decision Memorandum claims to authorize.

Even if it did, a DOD instruction cannot override the Posse Comitatus Act. Only an express provision in the Constitution or an act of Congress can do that. Indeed, to the extent that DODI 3025.21 purports to authorize military participation in law enforcement activities, it represents a violation of the Posse Comitatus Act rather than an exception to it. The IG attempts to avoid this problem by lumping together 10 U.S.C. §274, section 1059 of the 2016 NDAA, DODI 3025.21, and the 2018 White House Decision Memorandum and asserting that “federal law” authorizes the military’s involvement in law enforcement activities at the border. But only two of those four authorities could lawfully create an exception to the Posse Comitatus Act, and neither of them sanctions direct law enforcement activities.

A Dangerous Precedent

To be sure, the IG’s report also indicates that the Title 10 personnel at the border have not in fact been involved, at least not at any meaningful level, in direct law enforcement. Active duty troops have principally been engaged in support activities such as laying down concertina wire and operating surveillance equipment. Between October 2018 and December 2019, Title 10 personnel reported 183 encounters with civilians or migrants. According to the IG’s report, they did not perform law enforcement duties in any of these encounters.

But even if active duty troops have not been participating in direct law enforcement, the IG’s report is worrisome on several counts. To start, it offers cover were troops to begin performing law enforcement activities at the southern border. More generally, it typifies and perpetuates this administration’s casual approach to the laws and norms limiting domestic use of the military—as has also been shown by its use of National Guard forces to respond to protests in the wake of the police killing George Floyd. Finally, the IG’s sloppy legal analysis is troubling in itself, at a time when the credibility of government watchdogs is more important than it has ever been.


Image: MEXICALI, MEXICO –  A street candy seller walks the street while U.S. Army soldiers work fortifying the US-Mexico border fence with barbed wire on November 26, 2018 in Mexicali, Mexico. (Photo by Luis Boza/VIEWpress/Corbis via Getty Images)