Officials won’t explain why a Space Force commander was fired after joining a podcast to promote his book about Marxist ideas within the U.S. military.

Lt. Col. Matthew Lohmeier joined L Todd Wood on the “Information Operation” podcast to discuss his book “Irresistible Revolution: Marxism’s Goal of Conquest & the Unmaking of the American Military,” on May 7, according to CD Media.

Lohmeier was reportedly told that it was optional for superiors to review his book before its publication, according to Military.com. On Wood’s podcast, Lohmeier spoke about how American institutions, including the military, are embracing concepts like racial and economic equity training to divide Americans.

Lohmeier was relieved of command on Friday “due to loss of trust and confidence in his ability to lead,” a Space Force spokesperson told the Daily Caller News Foundation Monday.

“This decision was based on public comments made by Lt. Col. Lohmeier in a recent podcast,” the spokesperson added. Lohmeier’s comments will be investigated to determine if they “constituted prohibited partisan political activity.”

Lt. Col. Matthew Lohmeier was removed for raising serious concerns regarding Marxist ideologies.

He is a patriot and should not have been removed from his post. https://t.co/fT51L8jmO0

— Rep. Madison Cawthorn (@RepCawthorn) May 16, 2021

Lohmeier said the purpose of his book wasn’t to criticize any specific person but aimed at addressing policies service members are required to adhere to and expressing the hope that the Department of Defense (DOD) will be non-partisan in the future, Military.com reported.

Active-duty servicemembers thanked Lohmeier “for speaking up — because [they] don’t have a voice anymore,” he said on Wood’s podcast.

Military leaders are worried about advancement and success within the service if they don’t support the controversial initiatives, Lohmeier said, according to Military.com.

“The diversity, inclusion and equity industry and the training we are receiving in the military … is rooted in critical race theory, which is rooted in Marxism,” Lohmeier told Wood on the podcast.

His book looks at U.S. history and considers how social and economic institutions impact critical race theory and the U.S., according to Military.com.

“I was apprised of the option to have my book reviewed at the Pentagon’s prepublication and security review prior to release, but was also informed that it was not required,” Lohmeier told Military.com.

The DOD policies for self-published books such as Lohmeier’s might include guidelines for political activity while in uniform, Clements Center National Security Senior Fellow Jim Golby told Military.com. The guidelines wouldn’t prevent publication but could limit content based on information included about military matters like information, facilities and experiences.

Lohmeier criticized DOD Secretary Lloyd Austin for holding a stand-down on extremism in the military on Feb. 5, Military.com reported. Lohmeier said service members were given a book that called the Jan. 6 Capitol riot an extremist event but didn’t mention civil unrest following George Floyd’s in-custody death.

Lohmeier said critical race theory is a form of extremism by the DOD’s own definition and other service members should deny it, according to Military.com.

Lohmeier could not be reached for comment.