Retired Maj. Gen. Linda Singh said she’s worried about the president’s use of National Guard troops in American cities and his increasing threats to send them to Baltimore under what critics say is a pretense of helping to combat crime.

Singh knows firsthand the weight of deploying soldiers on U.S. soil.

She led Maryland’s National Guard deployment into Baltimore in 2015, after violent protests erupted following the death of Freddie Gray from injuries sustained while in police custody.

That was a crisis that warranted help, said Singh, who was appointed adjutant general by former Republican Gov. Larry Hogan. People were injured, businesses destroyed and the city ground to a halt.

She’s not seeing anything remotely like that now.

Singh and other senior military officers and veterans are speaking out against the use of troops — the legality of which is being in challenged in court — warning that the president’s actions politicize an apolitical institution and erode Americans’ trust in its military.

“We’re citizen soldiers and airmen. We’re part of the community. We’re happy to do our mission, but we’re not happy to be a pawn,” Singh said.

Before the 2015 deployment, she recalled tense conversations between top state and city officials weighing whether to send troops. Those decisions spooled out over days. And troops weren’t sent in until there was a clear mission, with defined rules of engagement and an exit strategy. The National Guard is there to support local residents in times of crisis, not to take over.

“Once things are stable we leave,” she said.

National Guard troops have been stationed in D.C. for about a month. As president, Trump controls the district’s Guard and sent them to patrol the streets after declaring a crime emergency even as homicides and many violent crime rates are trending down. The Guard, some armed, are most commonly in touristy pockets of the city and have been seen spreading mulch, picking up trash and taking selfies with passersby.

Trump has threatened to send National Guard troops elsewhere, including Baltimore, saying he has a right and an obligation to save cities with high crime rates. He’s paused plans to send troops to Chicago and instead will put them in Memphis. A judge ruled last month that Trump illegally used troops as law enforcement in Los Angeles. The president’s lawyers have appealed the decision.

Gov. Wes Moore and Baltimore Mayor Brandon Scott have said they would welcome more federal law enforcement officers and federal funds for crime prevention programs but not troops in the city.

Moore, a Democrat, serves as commander-in-chief of Maryland’s National Guard and in most circumstances has control over their deployment. Some rare and extreme exceptions allow the president to federalize the Guard without a governor’s consent.

The former Army captain said the guard picking up trash and painting fences in D.C. is an embarrassment to the people in uniform.

“Not only do I find that silly,” Moore said Tuesday on WBAL Radio, “I also find that amazingly disrespectful to the National Guard.”

Recent polling by CBS News and YouGov showed that more than half of respondents disapproved of Trump’s decision to send troops to D.C. and other cities, with Republicans largely in favor of the idea and strong majorities of Democrats and independents opposing.

The White House declined to comment on the president’s plans for Baltimore.

White House spokesperson Abigail Jackson said in an email that “all local leaders should see the tremendous results achieved by President Trump in DC and look to emulate them in their own cities.”

The Maryland National Guard has not received any federal mobilization orders to support missions in Baltimore or in any other state, according to a spokesperson.

Singh and others joined a friend-of-the-court brief Tuesday backing California Gov. Gavin Newsom’s case against Trump. A federal appeals court is weighing a lower-court ruling that Trump illegally used troops as law enforcement in Los Angeles.

Retired Maj. Gen. Paul Eaton of Key West, Florida, signed on too. Eaton was in the U.S. Army for 33 years and now serves as an adviser to national veterans advocacy groups.

Service members swear an oath to protect the Constitution from enemies both foreign and domestic, he said, “but the last thing we want to do … is to be used against our own citizens.”

Vet Voice Foundation, a veterans advocacy organization, cosigned the brief and represents nearly 2 million veterans, family members and supporters. Singh and Eaton are members.

“I’m speaking with a number of retired general officers, as well as folks who served at every level, who are very alarmed by what they’re seeing,” said Janessa Goldbeck, CEO.

Trump’s deployments have taken Guard troops away from their regular jobs, she said, “to participate in a partisan political stunt.” And she’s concerned about how these actions may risk the nation’s readiness to defend the country against foreign adversaries.

“We don’t have unlimited National Guard,” she said. “It’s not a bottomless pit of people.”

Top military brass aren’t the only ones objecting to Trump’s use of troops. A grassroots band of rank-and-file veterans has started a movement and has set up a base camp draped with camouflage netting outside D.C.’s Union Station.

Volunteers say they’re advising young soldiers of their rights and lending an ear.

“There’s a lot of people that are here in uniform that believe the same way that we do,” said Tanya Rhody, who served five years as an Army medical laboratory technician and came from Pennsylvania.

Air Force veteran Laura Watterson, called the deployments “embarrassing, terrifying and insulting.”

Goldbeck, Singh and others worry about the long-term effects of active-duty soldiers being villainized in their own communities, their morale and mental health.

Guard soldiers are mothers, fathers, daughters and brothers who put on a uniform and have lives outside of the military, Singh said.

“We’re going to do what we’re called to do,” Singh said. “But nobody talks about the emotional scars.”

Those scars don’t just come from deployments to war-torn foreign countries, she warned as someone previously responsible for thousands of troops, but could come during actions like these.

Should deployments continue to roll out in more cities, she wondered aloud what’s next for military members and asked a question she didn’t have an answer to: “How do we come out of this?”