President Trump’s proposal to create an entirely new branch of the military, the U.S. Space Force, may not be a good idea. But the initiative does point to a dangerous gap in our defense posture.

Trump’s idea is for a new service equal in stature to the Army, Navy, Air Force, Marines and Coast Guard. Creating a new bureaucracy to handle warfare out of sight above our heads probably is not the best way to handle the challenge.

But it is a genuine problem. As Vice President Mike Pence pointed out last week, U.S. adversaries have “pursued weapons to jam, blind and disable our navigation and communication satellites via electronic attacks from the ground. … As their actions make clear, our adversaries have transformed space into a warfighting domain already.”

Indeed they have. And though U.S. military capability in space is substantial, there are reasons to believe foes such as Russia and China are pursuing superiority actively.

Trump’s idea may not be the best solution — but it is a necessary wakeup call alerting Americans that our national defense cannot stop at the edge of the atmosphere.