Gen. David H. Berger testifies to the Senate Armed Services Committee on Capitol Hill, June 22, 2021.

Photo: joshua roberts/Reuters

Deference to senior command is a hard-wired tradition in elite military organizations, and nowhere is that tradition more honored than in the U.S. Marine Corps. But what happens if a policy coming from the top of the chain of command is insufficiently tested or intrinsically flawed? Where is it written that a subordinate or former commander can set aside deference and demand a second look?

For more than two years many of the Marine Corps’ finest former leaders have struggled with this dilemma as they quietly discussed a series of fundamental changes ordered, and in some cases already implemented, by Gen. David Berger, the current commandant. Among Marines there are serious questions about the wisdom and long-term risk of dramatic reductions in force structure, weapon systems and manpower levels in units that would take steady casualties in most combat scenarios. And it is unclear to just about everyone with experience in military planning what formal review and coordination was required before Gen. Berger unilaterally announced a policy that would alter so many time-honored contributions of the Marine Corps.

The unique and irreplaceable mission of the Marine Corps is to provide a homogeneous, all-encompassing “force in readiness” that can go anywhere and fight anyone on any level short of nuclear war. The corps has fought many political battles to preserve that mission but never from within—until now.

Among other decisions, Gen. Berger’s “Force Structure 2030” plan includes these provisions:

• Elimination of three infantry battalions from the current 24, a 14% reduction in frontline combat strength.

• Reduction of each remaining battalion by 200 Marines, taking an additional 4,200 infantry Marines from the frontline combat capabilities.

• Elimination of two reserve-component infantry battalions of the present eight, a 25% reduction of combat strength.

• Elimination of 16 cannon artillery battalions, a 76% reduction, to be replaced by 14 rocket artillery battalions, for use in “successful naval campaigns.”

• Elimination of all the tanks in the Marine Corps, even from the reserves.

• Elimination of three of the current 17 medium tilt-rotor squadrons, three of the eight heavy-lift helicopter squadrons, and “at least” two of the seven light attack helicopter squadrons, which were termed “unsuitable for maritime challenges.”

After several unsuccessful attempts by retired senior officers to engage in a quiet dialogue with Gen. Berger, the gloves have now come off. The traditional deference has been replaced by a sense of duty to the Marine Corps and its vital role in our national security. Recently, 22 retired four-star Marine generals signed a nonpublic letter of concern to Gen. Berger, and many others have stated their support of the letter. A daily working group that includes 17 retired generals has been formed to communicate concerns to national leaders. One highly respected retired three-star general estimated to me that “the proportion of retired general officers who are gravely concerned about the direction of the Corps in the last two and a half years would be above 90 percent.”

There is not much time to stop the potential damage to our national security. Questions should be raised. The law does not give the commandant of the Marine Corps carte blanche to make significant changes in force structure. Title 10 provides that the commandant perform his duties “subject to the authority, direction, and control of the Secretary of the Navy,” and that the Navy secretary “has the authority necessary to conduct all affairs of the Department of the Navy including. . . . organizing,” but “subject to the authority, direction, and control of the Secretary of Defense.” And the president retains ultimate authority as commander in chief.

The risk involved in a restructuring of this scale should have required full consideration and debate in such Pentagon offices as the Defense Resources Board, then a formal approval by the defense secretary before being sent to the White House for further review, and then extensive oversight hearings in Congress.

Few of our most serious members of Congress would have simply nodded and funded a program with almost irreversible long-term consequences. Gen. Berger’s announcement came during the Covid restrictions, when much of Congress had gone remote, and serious examination and oversight was extremely difficult. Added to that was the chaos that existed in the Pentagon during the 2020 campaign year and the inevitable postelection turbulence.

New ideas, even if they are bad ideas, have a way of gaining media attention. Predictably, some commentators have dismissed the concerns of the Marine Corps retired community as coming from a bunch of graybeards whose minds are still focused on yesterday’s wars. Such comments do no justice to the long tradition of combat innovation that has always marked the Marine Corps, from amphibious doctrine to helicopter usage to the techniques of close-air support.

If Gen. Berger’s new ideas were well thought out and tested, we would be seeing 90% of retired generals enthusiastically supporting them instead of expressing concern. But the realities of brutal combat and the wide array of global challenges the Marine Corps faces daily argue strongly against a doctrinal experiment that might look good in a computerized war game at Quantico.

Twenty-two four-star generals deserve to be listened to. For the good of the country, let’s hope they will be.

Mr. Webb was a Marine infantry officer in Vietnam, Navy secretary (1987-88) and a U.S. senator from Virginia (2007-13). He is the Distinguished Fellow at Notre Dame’s International Security Center.