Today during a speech to military members in San Diego, President Trump proposed the idea of creating an entirely new branch of the US military specifically geared toward war efforts in space. He dubbed this theoretical new branch the “Space Force,” noting that such a new agency could become reality soon.

The problem is Trump’s administration actively opposed the idea of a Space Force last year. In June, the House Armed Services Committee drafted legislation in the National Defense Authorization Act that would create a “Space Corps” within the US Air Force.

The Air Force didn’t want it and even the White House objected to the idea at the time, saying it would create more bureaucracy. “I oppose the creation of a new military service and additional organizational layers at a time when we are focused on reducing overhead and integrating joint warfighting efforts,” Defense Secretary Jim Mattis wrote in a letter to the ranking members of the House and Senate Armed Services Committees.

“We have the Air Force; we’ll have the Space Force.”

But that didn’t stop President Trump for advocating for a “Space Force” today. “My new national strategy for space recognizes that space is a war-fighting domain, just like the land, air, and sea,” Trump said at the rally. “We may even have a ‘Space Force’ — develop another one. Space Force. We have the Air Force; we’ll have the Space Force.”

Trump insinuated that the idea started off as joke, but that he might seriously be considering it. “You know, I was saying it the other day because we’re doing a tremendous amount of work in space. I said, ‘Maybe we need a new force, we’ll call it the Space Force,’ he said. “And I was not really serious, and then I said what a great idea, maybe we’ll have to do that. That could happen. That could be the big breaking story.”

Trump says that space is a "war fighting domain" and proposes a military "space force." pic.twitter.com/759ENLaIYj — Jack Smith IV (@JackSmithIV) March 13, 2018

Trump didn’t give any details about what the Space Force would do. But he is right that the Air Force’s operations are reliant on space. The Air Force has its own Space Command, which is responsible for overseeing the numerous GPS, communications, and surveillance satellites the military has in orbit. The military also operates spacecraft that can give early warnings about missile launches on the ground.

The “Space Force” is already a runaway meme on twitter, though, and it likely inspires ideas of weaponizing Earth orbit with military-style astronauts akin to Starship Troopers. However, that’s not happening anytime soon. (Also, the US is part of an international treaty that prohibits countries from putting nukes into space.) What Trump seems to be referring to is the Space Corps with a new name.

The proposed Space Corps would have functioned like the Marine Corps does within the US Navy; it would have been responsible for overseeing all of the Air Force’s operations in space. The goal was for the US to stay ahead of rivals like Russia and China, which are advancing in space-related military operations.

The Space Corps language was removed from the final version of the National Defense Authorization Act last year. However, the bill does leave the door open to a future space-related branch, The Hill reports, by requiring the Secretary of Defense to study the possibility of creating a space-related military branch someday. It’s unclear if Trump’s Space Force would be any similar to what the Space Corps was meant to be. But it seems like Trump is trying to resurrect an idea that his administration originally didn’t want.