President Trump has hurled so many thunderbolts recently that people may have missed the one that could have the greatest long-term impact on America’s national security — his directive to the Pentagon last week to start creating a new military service that he dubbed the “Space Force.”

It’s certainly a Trumpian idea: big and bold, with a Hollywood glitz factor; highly disruptive of the status quo; and lacking in any detailed planning about implementation. But many experts say the idea of revamping space defense makes some sense, though they caution that it requires a serious public debate about how to get maximum benefit at minimum cost.

Trump was emphatic in a June 18 speech to the National Space Council: “I’m hereby directing the Department of Defense . . . to immediately begin the process necessary to establish a Space Force as the sixth branch of the armed forces . . . separate but equal” from the Air Force. Knowing that the Pentagon resists the idea, Trump then turned to Gen. Joseph F. Dunford Jr., chairman of the Joint Chiefs of Staff, and said: “Got it?” Dunford answered: “We got it.”