Diane Schroer still went by Dave when she served 25 very honorable years in the U.S. Army as a Special Forces officer in many of the world’s hot spots, making the physical transition from male to female only after her retirement.

But Schroer would tell you plainly that all along she was a transgender person, the very type of individual who President Donald Trump now says will not be allowed to serve in the U.S. military “in any capacity.”

How ignorant. How sad.

How foolish that our nation would lose out on the talents of the next Diane Schroer or the thousands of other transgender individuals who have served, are serving and would yet serve our nation.

OPINION

And why kick them out exactly? Because they make some people uncomfortable?

“It devalues my 25 years of service. It is almost as if it didn’t happen, because under today’s rules, it wouldn’t,” Schroer, 60, told me Wednesday after the president’s Twitter pronouncement.

“I like to think I made a valuable contribution to my country, as many others are today, and this policy says: ‘Your service doesn’t matter, and can easily be eliminated.’”

I’ve written several columns about Schroer through the years.

BROWN: Should gender matter when you want to serve?

BROWN: Dave or Diane — being different no reason for guilt

BROWN: Before Caitlyn Jenner, there was my roommate, Diane Schroer

She grew up in Oak Lawn and attended Northern Illinois University, where we roomed together in an apartment near the football stadium my senior year.

She was a hard-charging ROTC student preparing for Airborne Ranger school who drove a 4-wheel drive Jeep, performed her own auto repairs and had the acid burns from a battery explosion to prove it. We shared many fine meals of Dinty Moore beef stew and Banquet frozen fried chicken.

And I never once had a clue about the inner conflict that shaped her life — the sense God had played a dirty trick on her by giving her a man’s body.

We stayed in touch only sporadically after college, but she contacted me in 2005 with the surprising (OK, stunning) news about her transition to female and a related development — a job discrimination lawsuit against the Library of Congress that she eventually won.

The groundbreaking case made her a nationally recognized figure in transgender rights, and I have been honored ever since to share her story.

I got in touch as soon as I saw the reports on Trump’s morning blurts. She was still trying to sort it out.

“It’s a little like don’t ask, don’t tell. You’re in the closet, but you’re still serving,” Schroer suggested.

I told her that might be a charitable interpretation. It seems just as likely Trump will want to actively identify and root out transgender soldiers.

Schroer worries what will happen to the many transgender individuals who self-declared during the past year after Barack Obama’s administration lifted the ban on transgender troops.

“If you’re self-declared, they have no choice but to eliminate you,” she said.

Schroer thinks the fundamental question is: “What is it about being transgender [that] makes it incompatible with military service?” She notes no other NATO army bans transgender service members.

Schroer believes estimates of 2,500 to 7,000 transgender U.S. service members on active duty miss the mark.

“I think it’s easily double or triple that,” she said.

Based on her own experience, she says transgender individuals are serving in all branches of the military — and at all ranks.

Even generals?

“I’m sure there are some. I don’t know of any that are currently on active duty, but I wouldn’t be surprised,” she said, choosing her words carefully.

Schroer, whose last Army posting was a high-level command job in the Pentagon, holds a civilian job these days with the U.S. Navy.

“When I hear the president talk about banning transgender service members, I hear the Library of Congress saying, ‘We don’t want you here. … You are not a good fit. We don’t need your dedication, skills, knowledge or potential,’” Schroer told me.

“It’s just wrong … on every level.”

So wrong.