WASHINGTON (AP) — President Donald Trump’s Pentagon chief shot down his idea of using troops to quell protests Wednesday but then reversed course on pulling part of the 82nd Airborne Division off standby in an extraordinary clash between the U.S. military and its commander in chief.

Both Trump and Defense Secretary Mark Esper also drew stinging, rare public criticism from Trump’s first defense secretary, Jim Mattis, in the most public pushback of Trump’s presidency from the men he put at the helm of the world’s most powerful military.

Esper angered Trump early Wednesday when he said he opposed using military troops for law enforcement, seemingly taking the teeth out of the president’s threat to use the Insurrection Act to send soldiers to states to “dominate” their streets. Esper said the 1807 law should be invoked in the United States “only in the most urgent and dire of situations.” He added, “We are not in one of those situations now.”

After his subsequent visit to the White House, the Pentagon abruptly overturned an earlier decision to send a couple hundred active-duty soldiers home from the Washington, D.C., region, a public sign of the growing tensions with the White House amid mounting criticism that the Pentagon was being politicized in response to the protests.

Former Secretary Mattis, a retired Marine general, lambasted both Trump and Esper in an essay in The Atlantic Wednesday for their consideration of using the active-duty military in law enforcement — and for the use of the National Guard in clearing out a largely peaceful protest near the White House on Monday evening.

“We must reject any thinking of our cities as a ‘battlespace’ that our uniformed military is called upon to ‘dominate,'” Mattis wrote, referencing quotes by Esper and Trump respectively. “Militarizing our response, as we witnessed in Washington, D.C., sets up a conflict–a false conflict–between the military and civilian society. “

Days ago, Esper had ordered about 1,300 Army personnel to military bases just outside the nation’s capital as Trump weighed whether to invoke the Insurrection Act and send active-duty troops into the city, the scene of large protests that devolved into violence and looting over the weekend. But after a night of calm enforced by a large deployment of National Guard troops and heavily armed federal law enforcement agents, defense officials said the troops would begin returning to their home base.

Army Secretary Ryan McCarthy told The Associated Press that the decision was reversed after Esper’s visit to the White House. The White House didn’t respond to request for comment on whether Trump ordered the change.

The shift added to confusion over the president’s threat to invoke the Insurrection Act for protests following the death of George Floyd in Minneapolis. White House officials had indicated even before Esper’s comments that Trump was backing away from invoking the act, though officials said Trump was upset that Esper’s statement conveyed “weakness.”

Press secretary Kayleigh McEnany said the president was still willing to deploy federal troops despite Esper’s comments.

“If needed, he will use it,” she told reporters. “But at this time he’s relying on surging the streets with National Guard. It’s worked with great effect.”