Lieutenant Gen. Robert S. Walsh, commanding general, Marine Corps Combat Development Command, and deputy commandant, Combat Development and Integration, poses for a photo before participating in a pre-game lineup delivery during U.S. Marine Corps Day at Nationals Park, Washington D.C., July 31, 2018. (Official U.S. Marine Corps photo by Sgt. Robert Knapp/Released)

QUANTICO, Va. — As seemingly happens after every major U.S. conflict, Congress is again questioning why the nation should maintain the Marine Corps as an amphibious force when joint warfighting, multi-domain operations and proliferating cruise missiles make another Iwo Jima unlikely.

Lt. Gen. Robert Walsh, who as deputy commandant for combat development and integration oversaw creation of the service’s current operating concept, has a simple answer: Marines were doing joint and multi-domain operations before they were cool.

Walsh will close a 39-year career in August as the officer in charge of developing and integrating equipment, weapons and operational concepts into the Marine Air-Ground Task Force (MAGTF). The MAGTF is a modular, scalable fighting force that includes everything from F-35 Joint Strike Fighters and CH-53 heavylift helicopters to amphibious combat vehicles and infantry squads all packed aboard Navy amphibious ships.

“It is very easy to understand why you have an Army to fight on land, an Air Force to establish air superiority and a Navy to provide sea control,” Walsh said July 30 during an interview in his office at Quantico. “The MAGTF doesn’t fit as well, but I’d argue we’re perfectly suited for how we’re going to operate in the future.”

Now the Army is talking about firing on enemy ships from the land, the Navy is turning every surface vessel into a combatant and the Air Force is managing air superiority within and outside earth’s atmosphere. The Marine Corps, by contrast, was created to straddle two – then graduated to three – domains. It now regularly operates at a large scale on land, at sea and in the air, Walsh said.

“This is not that difficult, because we used to do this very well,” Walsh said.

Congress in the fiscal 2019 National Defense Authorization Act (NDAA) is requiring the Defense Department to reevaluate the “highest priority missions of the Department of Defense and of the roles of the Armed Forces in the performance of such missions.” It also asks “whether the joint force would benefit from having one Armed Force dedicated primarily to low-intensity missions.”

Considering the specific details Congress wants in the report, it is clear the Marine Corps’ purpose is being challenged.

Specifically, the NDAA requires an assessment of whether “amphibious forced entry operations against advanced peer competitors should remain an enduring mission for the joint force, considering the stressing operational nature and significant resource requirements of such missions.”

A Google search for “Why does U.S. need a Marine Corps” turns up more than a dozen explainers on the first pages of results. After serving in World War II, Korea and Vietnam, Lt. Gen. Victor Krulak wrote the seminal argument for maintaining the U.S. Marine Corps in his book “First to Fight,” which is on the commandants reading list. Walsh rereads it every year.

“We are always proactively looking at ourselves to see where the future should take us,” he said. “We know our history. Are we going to conduct amphibious operations in the future? Probably. Are we going to have another Iwo Jima? Probably not; at least it won’t look like that.”

Congress also wants an “assessment whether a transition from large-deck amphibious ships to small aircraft carriers would result in a more lethal and survivable Marine Corps sea base that could accommodate larger numbers of more diverse strike aircraft.”

“I look at that NDAA language and am confident that we can fit in,” he said. “It’s not all about Marines storming the beach. Because the Marine Corps is smaller, we can move faster,” on deployments and toward modernization, Walsh said.

Walsh recognizes the Marines have been focused on counterinsurgency campaigns for the better part of 20 years, but that changed in 2016 with the publication of a new Marine Corps Operating Concept that focused on great-power competition. Wargames that showed the Marine Corps, as then-trained and equipped, was vulnerable to defeat by near-peer competitors in a conventional fight was “a wakeup call in many ways.”

“Those strategies, that was the first time in 10 years that we had a National Defense Strategy that really set us on a new course,” Walsh said. “It was a clear route of march for us.”

The service began cozying back up to the Navy by deploying Marines and equipment aboard ships rather than simply using them as ferries to landlocked war zones. The new Marine Corps Operating Concept prescribed a return to large-scale, full-spectrum operations against state-sponsored militaries. Success in that type of combat environment requires joint operations with the Navy, Army and Air Force to provide sea control and dominion of the air, he said.

That redirection was underscored this year by publication of the National Defense and National Security strategies, both of which downplayed the threat of global terror and instead focused on strategic competition by Russia and China, the nuclear threat from North Korea and rogue, destabilizing tendencies of Iran, Walsh said.

“Looking back reflectively, after 17 years focused on defeating a very specific type of enemy, we’re starting to focus on things other than the Taliban or ISIL,” Walsh said. “With the return to strategic competition, we’ve got to be able to defeat all threats, not just insurgent threats.”