“Trying to explain this to the public has been difficult,” said Eric Fanning, president and CEO of the Aerospace Industries Association.

WASHINGTON — So little is known publicly about the arms race unfolding in space that even retired four-star General Jim Mattis did not consider it a major issue until he became secretary of defense.

“I will tell you I did not recognize the degree of the problem when I went through confirmation,” Mattis told Rep. Mike Rogers, chairman of the House Armed Services Committee strategic forces subcommittee. “What you and your colleagues have done have brought it to our attention,” Mattis said during a committee hearing last week.

Under Mattis, the Defense Department adopted a new strategy that regards space as a domain of warfare. The administration has increased the military budget for space programs by 14 percent.

Outside national security circles, however, it is hard to grasp why space is “contested” or why the United States would have to worry about security threats in space.

“Trying to explain this to the public has been difficult,” said Eric Fanning, president and CEO of the Aerospace Industries Association.

A former secretary of the Army and undersecretary of the Air Force, Fanning received many intelligence briefings on the subject. “What a lot of people don’t know is that this is not new,” he said in an interview with SpaceNews.

“Those of us that have worked in government and have been briefed know what the threats are,” said Fanning. But access to information outside government is limited, he said.

AIA, an organization that advocates for increased government investments in defense and space, helped fund a study that was released last week, “Space Threat Assessment 2018,” by the Center for Strategic and International Studies’ Aerospace Security Project.

The study lists potential U.S. adversaries’ space capabilities using unclassified open-source materials. It follows the release of a more in-depth study by the Secure World Foundation on counterspace technologies that are proliferating around the world.

Fanning noted that the United States is hugely dependent on a “space architecture we designed a lot like the internet, not with threats in mind.” In the study, “we try to communicate that to the public, not only how vulnerable our assets are but what that means, not just for the military, but for things we do every day.”

“It’s a struggle we’ve had as a community to figure out how to explain this beyond our community,” said Fanning. “We pulled the open source material to see if there’s enough out there to be made into a story that makes the case that we have to take this seriously.”

In the study’s preface, retired Air Force Gen. Robert Kehler, former commander of U.S. Strategic Command, noted that the environment has changed dramatically since the end of the Cold War. Back then, “we expected and planned for the Soviet Union to employ its significant capabilities to disrupt or destroy our space assets,” Kehler wrote. “However, today’s problem is far more complex and potentially far greater in impact than the Cold War scenario. Given our dependence and that of our allies and partners on space, the loss of critical assets today could prove decisive to our ability to monitor critical events like missile launches or nuclear tests, or to successfully prosecute a military campaign.”