There’s a Dangerous Misconception About the Military’s Obligations to the President

The prospect of a second Trump administration has rekindled a debate from four years ago about the proper role of the military in our democracy.

During the tumultuous period before and after the 2020 presidential election, several extraordinary conflicts took place between Donald Trump and senior leaders of the military. In June 2020, for example, Defense Secretary Mark Esper said publicly that active-duty military should not be used to control protests in American cities — despite a threat from Mr. Trump to do precisely that.

Likewise, Gen. Mark Milley, the chairman of the Joint Chiefs of Staff, took a series of unusual steps during the final months of the Trump administration to protect the country from a president who he believed was looking for ways to remain in power. General Milley even went as far as to solicit assurances from the military chain of command that it would not launch a nuclear strike on Mr. Trump’s order without his involvement.

Recent reporting has raised concerns that a second Trump administration would once again strain relations between the military and civilian authorities. Mr. Trump and his potential appointees are apparently considering deploying the military for a variety of purposes that might invite scrutiny from military leaders: to patrol the border, arrest undocumented immigrants, combat urban crime and quell protests.

Now, as then, a question arises: When is the military permitted (and perhaps obligated) to criticize or even refuse an order from a commander in chief — and when must it defer?

Of course, if an order is clearly illegal, service members are legally bound to disobey it. But the law in this space can be ambiguous. For example, the Posse Comitatus Act of 1878 generally prohibits using the U.S. military for domestic policing purposes, but that prohibition has exceptions — and the Insurrection Act of 1807 grants the president the authority to unilaterally deploy the military to restore domestic law and order. A president’s advisers have plenty of wiggle room to make reasonable-sounding legal defenses of domestic policing operations.