Washington — 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 Dunford, chairman of the joint chiefs of staff, and said: “Got it?” Dunford answered: “We got it.”

The Pentagon fears that launching a separate space contingent would set off one of the epic turf wars that have been a regular feature of U.S. military history. These rivalries often follow the advent of new technologies. The Air Force emerged from the cocoon of a jealous Army only after World War II. When missile technology advanced in the 1950s, the Army argued that it was a form of artillery that should be controlled by its ballistic specialists, while the Air Force insisted it was part of the aeronautical domain. The Air Force had assumed space was its responsibility, until last week.

“This will mean nonstop bureaucratic arm-wrestling for the next five years,” warns John Hamre, a former deputy defense secretary who heads the Center for Strategic and International Studies. While recognizing the infighting that’s ahead, Hamre, like many other Pentagon veterans, believes that some changes could enhance space-warfare capabilities that have been badly botched by the Air Force.

“We have squandered our advantage in space; the Air Force went for a decade with no defense systems for satellites, after the military threat to them was clear,” argues Rep. Jim Cooper, D-Tenn., who joined Rep. Mike Rogers, R-Ala., last year in a bipartisan House move to create a semi-autonomous space “corps” within the Air Force, much as the Marines are part of the Navy.

The Pentagon helped shoot down the “corps” idea a year ago. Defense Secretary Jim Mattis wrote congressional leaders last October: “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 functions.”

But Trump continued to push his pet space project. One advocate was Vice President Mike Pence, chairman of the National Space Council and a rocket enthusiast who’s said to have brought his family to Florida to watch NASA launches. Another was Newt Gingrich, the peripatetic former House speaker who, like Trump, enjoys promoting flashy, controversial ideas.

“If Trump can break through the bureaucracy, all this will happen within a decade,” even by 2020, Gingrich predicted in a phone interview Tuesday. Gingrich, who informally attends Space Council meetings, says he has talked with Trump about the idea, but that the passion for it is the president’s.

The Air Force had been hoping that this proposal would go away. When I traveled last month to a space conference in Colorado Springs with Air Force Chief of Staff David Goldfein and Secretary Heather Wilson, they dismissed any suggestion that their service’s control of space defense might be challenged. After so many months in denial, the Air Force is now “largely out of the loop” in planning, but “it’s going to happen without them,” says Todd Harrison, director of aerospace studies at CSIS.

Pentagon officials say they understand that the commander in chief has spoken, and that they’re now thinking about how best to implement the space force directive. Two feasibility studies, mandated by Congress, are due later this year. The Pentagon hopes that will allow some thoughtful discussion of costs and benefits. But Gingrich warns that any attempt to slow-roll Trump will be “dangerous.”

A space revolution is underway, quite apart from Trump’s edicts. Private companies are pioneering new launch technologies that are driving down costs; Russia and China are developing exotic space weapons that could cripple America in any future conflict. It’s a good moment to think about reshaping space defense — creatively but carefully.

— David Ignatius is a columnist for Washington Post Writers Group.