When President Donald Trump first announced that he was directing the Pentagon to establish a “Space Force” as the sixth branch of the U.S. military, many Americans reacted by rolling their eyes and Googling whether Mars Attacks! was still on Netflix. (It is not.)

One month later, however, the Pentagon is close to releasing a report on how it plans to reorganize the American military’s presence in space—including how to make Trump’s “separate but equal” space-based military branch a reality. The possibility has national security and space experts deeply worried about the beginning of a new, space-based arms race—and the further deterioration of already-tense relations between the United States and the world’s other “space powers”: Russia and China.

“All of the major space players, except for Japan, are nuclear powers,” Dr. Laura Grego, a senior scientist at the Union of Concerned Scientists’ Global Security Program, told The Daily Beast in an interview. “And obviously, we don’t want extra pathways to confrontation between nuclear powers.”

Building the “muscular fighting force in space” that Trump envisions, Dr. Grego said, runs the risk of being seen as a challenge to spacefaring nuclear powers in outer space, an environment where there are no established rules of military engagement.

“Without clarity about how to respond in the event of malfeasance in outer space, that can be really dangerous,” Dr. Grego warned.

The problem with “Space Force” begins with its bellicose name, which—in addition to its B-movie, Starship Troopers-esque overtones—gives the impression that the U.S. has decided that a much more aggressive posture in space is in its interests.

“Calling it a ‘Space Force’ isn’t helpful—especially if you don’t really want it to turn out that way,” Dr. Grego said. Supporters of reorganizing the American military’s presence in space tend to call their proposal a “space corps,” rather than a ‘Space Force,’ “which does change the tenor quite a bit.”

That tenor is clearly not one President Trump, whose fascination with the military revolves almost entirely around its destructive capabilities, is interested in striking. When Trump first floated the concept of a “Space Force” in March, during a speech at Marine Corps Air Station Miramar in San Diego, he called space “a war-fighting domain, just like the land, air, and sea.”

The Department of Defense, however, appears to disagree.

Secretary of Defense Gen. James Mattis is on the record as opposing the creation of a space-based military branch. In a letter written to Congress last July, Mattis said that the establishment of a “Space Force”-type branch “would likely present a narrower and even parochial approach to space operations versus an integrated one we’re constructing under our current approach.”

Mattis has been backed up by Secretary of the Air Force Heather Wilson, who echoed Mattis’ fear of bureaucratic buildup, telling CNN that “the Pentagon is complicated enough” without an expensive and ill-defined new branch of the armed services. “If I had more money, I would put it into lethality, not bureaucracy.”

A Pentagon spokesperson did not address Mattis or Wilson’s comments, telling The Daily Beast only that the president’s directive, “which has implications for intelligence operations for the Air Force, Army, Marines and Navy,” will be examined through “a deliberate process.”

Part of the Pentagon’s concerns—both bureaucratically and militarily—is the lack of specificity to Trump’s demand that his “Space Force” join the Army, Navy, Marines, Air Force and Coast Guard in defending American interests beyond the stars.

“ I wouldn't necessarily say the Pentagon is slow walking the concept, because there is no substantive proposal. Trump directed them to do it, but someone actually has to figure out what it all means,” Dr. Brian Weeden, technical advisor for Secure World Foundation, a private organization dedicated to the secure and sustainable use of space. “ If you were to ask ten people what the mission of the ‘Space Force’ would be and how it would be organized, you'd probably get ten different answers.”

Currently, the Pentagon’s efforts in space are primarily a supportive function: the launching and maintenance of communications satellites, monitoring near-Earth objects and enabling space exploration. T he Air Force is responsible for the vast majority of U.S. military presence in space, but the Army, Navy, and Marines all maintain their own space programs, in addition to the National Reconnaissance Office, which runs most of America’s intelligence program in space, “which is at least as big as what the Air Force does,” Dr. Weeden said.

“The question is, should the Air Force continue to do it, or should we move it under a separate structure,” Dr. Weeden continued. “Does that look like a completely independent service? Or something like the Marine Corps where it still relies on the Air Force for some overhead and administrative functions?”

“Or, do we get really crazy, and push for something like the Coast Guard that has a peacetime safety and law enforcement function but can become part of the military in wartime? Or do we do both a Space Corps and a Space Guard?”

Trump’s proposal lacks all of these details. The Pentagon, being relatively detail oriented, is currently putting the final touches on a study that examines how a space-based branch would work within the Department of Defense. The study, mandated by Congress in the 2018 National Defense Authorization Act, is due to be complete by August 1.

“Until that study is done,” Dr. Weeden said, “we really have no idea what the end state will be, how it will be done, how long it will take, or what it will cost.”

But there is an increasing nervousness in military circles about the vulnerability of American assets in space. “Nearly half of all satellites are U.S. flagged,” Dr. Grego said, and “they’re really vulnerable” to interference or obstruction by hostile actors.

“At the same time, they’re not getting shot down all the time.”

The history of military involvement in space is relatively peaceful—a surprise for those who lived through the space race between the United States and the Soviet Union. The military has been in space for as long as humanity has, primarily with satellites that performed strategic functions, like early warning of ballistic missile launches.

“Most countries determined that those were good,” Dr. Grego said. “Nobody wanted to target each others’ early warning satellites, because that looks like a prelude to nuclear war.”

In the known history of space exploration, in fact, no nation has ever intentionally destroyed another’s satellite (although there have been instances of intentional interference with satellite communications).

Even as U.S.-Russia relations have deteriorated, cooperation between the two nations’ civil space programs have been “ a bright spot” between Washington and Moscow, Dr. Grego said. “We’ve managed to tend that small, really nice peace for a long time.”

The creation of “Space Force” could upend the unspoken policy of strategic restraint in space, however, accelerating a push by current space-faring nations towards openly developing weapons in space.

Dr. Joan Johnson-Freese, former chair of the U.S. Naval War College’s national security affairs department, called such a development “the rubicon yet to be crossed from the militarization of space which occurred in the 1940s.”

Think of it as Chekhov’s raygun: A hugely expensive military endeavor has to legitimize its own existence—and one of the best ways is for it to be used.

“That’s one of the dangers about a ‘Space Force’—you build a bureaucracy that has to justify itself, and maybe that can take on a life of its own,” Dr. Grego said.

A duo of exhaustive studies have determined just as much. In the Secure World Foundation’s Global Counterspace Capabilities: An Open Source Assessment, authors found that the growing use of space for national security “has also led more countries to look at developing their own counterspace capabilities,” which could be used to “deceive, disrupt, deny, degrade, or destroy space systems.”

The Space Threat Assessment 2018, penned by experts at the Center for Strategic and International Studies (CSIS) think tank, calls the U.S. military’s dependence on “a natural target for adversaries to exploit,” particularly as the Pentagon eyes devoting even more resources to counterspace technology.

“Both Russia and China reorganized their military space forces in 2015, so in some respects they are already ahead of us when it comes reorganizing around space forces,” Todd Harrison, director of the Aerospace Security Project at CSIS and one of the assessment’s authors, told The Daily Beast. “Russia and China are making progress developing their own space systems to support their militaries and developing counterspace systems that can threaten the space systems of others.”

Both China and Russia are building anti-satellite weapons, according to the two surveys, as well as a broad range of kinetic (i.e. destructive) and electronic counterspace capabilities. Credible reports indicate that currently Russia uses electronic warfare measures like satellite jamming in its military intervention in eastern Ukraine, and considering Russia’s demonstrable use of cyberattacks in other arenas, the Kremlin’s potential threat to space assets could be considerable.

If there were a war in space, the United States is the country that has the most to lose. With more assets in space than any other nation—communications satellites, remote sensing satellites, weather satellites, not to mention a sizeable chunk of a very expensive space station. Conflict in space puts all of those assets at considerable risk.

“When you look at it carefully, you have to ask, what problem does that solve, and what problems does that create?” Dr. Grego asked. “Why are we picking a fight in a place where we have so much to lose?”