There is ample historical precedent for a president, pursuant to his authority as commander-in-chief, to intervene in military affairs. President Lincoln appointed and fired a number of Union generals during the Civil War, President Truman famously relieved General Douglas Macarthur less than a year into the Korean War, and President Nixon commuted Army officer William Calley’s sentence for his role in the My Lai Massacre. Although there may be no precedent for a president using social media as a means of intervention in military policy, it is no less legitimate to do so than via more conventional means.

On July 2, 2019, Navy SEAL Eddie Gallagher was convicted of posing for a photograph next to a deceased ISIS fighter. A court-martial panel sentenced Gallagher to four months of confinement, and to be reduced in rank from Chief Petty Officer to Petty Officer First Class. President Trump intervened and restored Gallagher’s rank to Chief Petty Officer.

Reports later emerged that the Navy had commenced proceedings to potentially strip Gallagher of his designation as a Navy SEAL and remove his Trident Pin. On November 2019, President Trump used the social media platform Twitter to state that the U.S. Navy “will NOT be taking away Warfighter and Navy SEAL Eddie Gallagher’s Trident Pin.” Then-Secretary of the Navy, Richard Spencer, responded “I need a formal order to act,” and “I don’t interpret them as a formal order.” Mr. Spencer is not entirely accurate.

Presidential tweets can indeed constitute a lawful military order. And contrary to Mr. Spencer’s assertion, military officials do not need a formal order to act.

Under the Uniform Code of Military Justice (UCMJ), Congress established that personnel who are subject to the UCMJ must obey all lawful orders. While the UCMJ itself does not define what constitutes a lawful order, Congress delegated that authority to the President, who does so via the Manual for Courts-Martial (MCM).

According to the MCM, a lawful order need not be formal, or take any particular form. “As long as the order is understandable, the form of the order is immaterial, as is the method by which it is transmitted . . ..” Moreover, to be lawful, an order need only “be a specific mandate to do or not do a specific act.”

Some might question whether President Trump’s use of Twitter nullifies any official imprimatur. This, too, it seems is immaterial.

In June 2017, then-White House Press Secretary, Sean Spicer, stated that President Trump’s tweets are “considered official statements by the President of the United States.” The Department of Justice recently adopted this position in litigation before the U.S. Court of Appeals for the Second Circuit. See Knight First Amendment Inst. at Columbia Univ. v. Trump, 928 F.3d 226 (2d Cir. 2019). In Knight, the Second Circuit agreed, ruling that “the President’s tweets can accurately be described as government speech.” Id. at 239. Thus, because President’s Trump’s tweets are official statements.

In summary, the President can formulate military policy via social media. To be clear, every tweet or post will not rise to the level of a lawful order. But so long as the President issues a specific mandate to do or not do something that is within his or her constitutional authority as Commander-in-Chief, the use of social media does not render such an order unenforceable for want of formality.