Trump chooses words carefully regarding border — for a reason

If you’re interested in what the armed forces legally can and can’t do at the U.S. southern border, you should know that President TrumpDonald TrumpHillicon Valley — State Dept. employees targets of spyware Ohio Republican Party meeting ends abruptly over anti-DeWine protesters Jan. 6 panel faces new test as first witness pleads the Fifth MORE’s use of the military to date is entirely legal, despite inaccurate media reporting, and he has room to expand the military’s role under the law and existing policy. On Nov. 20, the president signed a decision memorandum expanding the role of the armed forces at the border, “including lethal force, where necessary.”

The specific wording of his memo is important, since the wording is deliberate, methodical and anything but coincidental. Phrases such as “protect the integrity of the southern border” and words such as “violence” and “disorder” are significant; they establish a foundation for further military action at the border if the president deems it necessary.


The armed forces can engage in domestic law enforcement activities provided certain conditions are met (invocation of the Insurrection Act, or declaration of homeland defense mission). Such conditions present exceptions to the Posse Comitatus Act, which prohibits use of the military for civilian law enforcement, and the latest memo may set us on this path.   

The border memo cites “credible evidence and intelligence” that the migrant caravan may “prompt incidents of violence and disorder” that may threaten federal personnel and their ability to “secure and protect the integrity of the southern border.” Though it’s difficult to assess the credibility of this claim, these words are informed and deliberate. The memo was prepared by a Harvard-educated lawyer and signed by a retired Marine Corps four-star general who served both as commander of U.S. Southern Command and secretary of Homeland Security — informed men who chose these words for a reason.

Consider the words “violence” and “disorder.” The legal definition of insurrection includes both words. Further, the memo’s reference to protecting the integrity of the border aligns with the homeland defense doctrine’s emphasis on protecting national sovereignty, including against illegal immigration. Finally, consider the president’s continued use of the word “invasion” in his public comments and tweets. The Calling Forth Act provides the legal mechanism for Congress to use military force to “repel an invasion.”

The memo also expands permissions for military personnel to include crowd control, temporary detention and cursory search. Although these actions can be considered law enforcement functions, they are justified under the “such other actions” or “such activities” wording contained in Department of Defense policy. Remember, too, that policy is not law and can change as circumstances dictate. Expanding authorities further would be difficult for the president to justify without consistent narrative including the words invasion, violence, disorder and threat. In using these words, the president continues to inoculate the public to the idea and establishes a defensible foundation for invoking exceptions to the Posse Comitatus Act.   

While security and legal experts sharply question the legality of the memo, so far everything the president has done is legal. Whether this is a political stunt or an overreaction is for others to debate; but obscuring the narrative by distorting or mistaking legality does a disservice to the public. The fact is, it remains clear what is and is not permissible under the law and associated policies governing domestic military support efforts.

The president’s guidance to the armed forces, authorizing use of lethal force at the border, remains within the legal authority of his office to ensure the safety and security of the nation. Justifying an expanded law enforcement role for the armed forces requires only that the president declare the migrant caravan a threat to our sovereignty. If he believes the United States must have secure, enforceable borders to be a secure, sovereign nation, anything he perceives as a threat to the security or enforceability of the borders will be considered a danger to our sovereignty, and he will act accordingly.

Ryan Burke, Ph.D., is an associate professor of military and strategic studies at the U.S. Air Force Academy and a former Marine Corps officer. The views expressed here are his and do not reflect the official position of the United States Air Force Academy, Department of the Air Force, or Department of Defense.