To succeed against a peer adversary, the Navy, Marine Corps, and Coast Guard must be able to operate together seamlessly. Marine Corps leaders have repeatedly acknowledged this, but efforts among the Sea Services to achieve the level of necessary interoperability remain limited and subordinate to each’s individual priorities. Technological and structural modernization are both important to being ready for a future conflict; but, for the Marine Corps to achieve naval service interoperability, it must forge relationships and invest in sufficient human capital to foster the understanding required to fight and win future wars.
Force Design 2030 has led to numerous changes in equipment and force structure, but the service has not dedicated the same level of effort or action to interoperability with the Navy, Coast Guard, and other services.The only noteworthy achievement of this interoperability effort is the ongoing discussion among the Commandant of the Marine Corps, Chief of Naval Operations, and Secretary of the Navy on how many amphibious ships are required—although there is not yet consensus even on that.1 This only serves to reinforce the current state of affairs regarding Marine Corps and Navy integration.
Currently, less than a quarter of the active-duty Marine Corps has accrued any at-sea time.2 Most of these Marines have done only a single shipboard deployment in their careers, with the average cumulative time a little more than six months.3 With few exceptions, they are with squadrons deployed on aircraft carriers, with amphibious staffs, and on board amphibious ships. Ultimately, Marines directly interact with less than 10 percent of the Navy. This lack of exposure and experience across the Marine Corps could prove a critical vulnerability in future operations.
When the Marine Corps does address interoperability with the Navy, it focuses primarily on technology—Will a given Marine Corps system work with the ship’s systems? Full interoperability requires linking the systems together and codifying operating procedures. “Green” systems are generally only integrated onto Navy ships in preparation for deployment and subsequently removed following deployment. This leads to the loss of individual and institutional knowledge as well as long lead times for future integration. Technical challenges can be identified and resolved, not to mention prevented, with early coordination. But waiting until the proverbial balloon goes up is not a good solution.
Interoperability does not primarily require new or more exquisite equipment or new bridging technologies. Instead, Marines should be integrated with the Navy to maintain and employ equipment already fielded (or in development) on an ongoing basis. Regular use of these systems will identify issues, improve interoperability challenges, and permit development of best practices to operate seamlessly when deployed.
Advantage at Sea
Marines can ensure success alongside the Navy in two primary ways: as part of a ship’s deckplate-level crew and as part of a unit’s operational staff.
Serving on board ships has been a part of the Marine Corps’ DNA since the beginning, even if it (understandably) has not been a priority over the past 20 years of land war in the Middle East. The mandate was set out at the Marine Corps’ establishment in 1775 “that particular care be taken, that no persons be appointed to office, or enlisted . . . but such as are good seamen, or so acquainted with maritime affairs as to be able to serve to advantage by sea when required.”4 This idea is as relevant today—and will be in the future—as it was in 1775.
Marine expeditionary unit and amphibious ship deployments alone are insufficient to build relationships between Marines and sailors. Ship maintenance and operational requirements make increasing Marine expeditionary unit deployments a challenge. To increase naval familiarity, Marines need to integrate onto more classes of ships. Numerous Marine Corps military operational specialties are already closely aligned with Navy ratings, including administration, intelligence, information systems, and supply. In some cases, Marines and sailors even went to the same technical schools—many aviation military occupational specialties shares schools, for example. With only limited additional training, many Marines could almost certainly serve on most ships, including cruisers, destroyers, and submarines.
Marines assigned to ships could bring their service’s unique capabilities, aiding naval missions and filling key billets, while starting from a similar baseline as many sailors. Navy communication, intelligence, food service, supply, administration, security jobs, and so on all can be filled by Marines with minimal additional training. Sailors at a given command would continue to outnumber Marines in those billets. Junior Marines do not need assignments for three-year tours, but with experience ahead of time, they could augment the Navy supporting the preparation, deployment, and postdeployment cycle of 12 to 18 months. Marine detachments at major naval bases or their parent Marine expeditionary forces could manage and maintain oversight of the Marines. However, more senior individuals—sergeants through master gunnery sergeants as well as commissioned officers—should receive assignments similar in length to their Navy officer and petty officer counterparts. This would enable the Marines to be fully accepted as part of ship’s company.
Longstanding positions at Marine Corps division-level (and above) staffs have been filled by Navy personnel for quite some time. Multiple factors have stymied their ability to support interoperability, however. Many serve more as liaisons than true staff officers on par with their Marine counterparts. In addition, most Navy personnel assigned to Marine Corps commands are command master chiefs, chaplains, and medical personnel who serve as special staff and advisors. The most pressing issue is that many Navy billets in Marine Corps units—regular or special staff—often go unfilled. The Marine Corps’ track record for filling billets within Navy units is not any better. To achieve a seamless Sea Service design, the current level of engagement is insufficient and needs to increase markedly.
In the Air, on Land . . . and Sea
The Marine Corps needs to assign more officers and senior enlisted to Navy staffs to serve as subject matter experts. This would require those assigned to learn more about naval operations, which may require additional schooling. However, the extra knowledge would not only serve the Marines well during Navy assignments, but also would provide new perspectives for when they return to Marine Corps units. The greater imperative is expanding Marines’ engagement on staffs beyond amphibious warfare to other Navy components, including aviation, submarines, Naval Special Warfare, surface warfare, and logistics. Interoperability and integration would allow and even require Marines to increase Navy staff knowledge about Marine Corps capabilities, supporting and improving fleet integration.
Manpower is a zero-sum game, meaning the Marine Corps cannot make this investment unilaterally. The Navy would need to reciprocate, augmenting Marine Corps units with sailors beyond today’s chaplains, corpsmen, and other medical professionals.
The Marine Corps should likewise make similar personnel investments with the Coast Guard, albeit at a much smaller scale. The Coast Guard’s unique capabilities and forward posturing will make it a critical partner in any fight in the Pacific. The Coast Guard and Marine expeditionary units both conduct visit, board, search, and seizure activities, and the Marine Corps is looking to invest in ships of sizes similar to some Coast Guard cutters.
The assignment of Marines throughout the fleet would create and strengthen service relationships. Doing so would not only enable success in future conflict, but also build the procedures and trust required to fight together. Marines should understand the composite warfare commander construct and be capable of employing it as a precursor to serving as a composite warfare commander. However, integration would require some changes in current Marine Corps tactics, techniques, and procedures for specific capabilities. Marines distributed throughout the naval force would be able to educate ships’ commanding officers regarding Marine Corps capabilities and employment. The established relationships at the highest levels of command between Marine forces and numbered fleets is critical, but relationships at lower levels of command could be just as important.
Interoperability of the naval force will require extensive commitment from each service. By committing to achieve true naval interoperability in the near term, the blue-green team will be able to combine the prowess of the individual services in an exceptional, globally operational force. The Marine Corps must be a force-enabler for the Navy. Integrating more Marines into nonamphibious naval staffs and commands would be a prudent first step that could have immediate and tangible positive effects.
In 2020, then–Commandant of the Marine Corps General David Berger redesignated numerous Marine Corps units with the proud title of “Fleet Marine Force.”5 The Marine Corps must carry this beyond a mere title, however: Reembark Marines more widely in the fleet. The Commandant told Congress in 2022: “As Secretary Austin highlighted, ‘our most critical asset . . . is our people.’ I believe this is even more relevant within the Marine Corps.”6 He was speaking about talent management and taking care of Marines and their families, but his message also applies to service investments. If the Marine Corps is not committing its people to the right places, and instead relies on technology to solve its most pressing challenges, then it is making a mistake. Now is the time to integrate the naval services on the high seas. Reembark the Marines.
1. Brent Sadler, “This Ugly Dispute Over Amphibious Warships Didn’t Have to Happen,” Defense One, 23 March 2023.
2. Manpower Information Request 27383 (Washington, DC: Headquarters Marine Corps, 2023).
3. Manpower Information Request 27383.
4. Resolution of the Continental Congress, 10 November 1775.
5. Gen David H. Berger, USMC, MarAdmin 305/20: “Implementation Guidance for the Standardized Use of Fleet Marine Forces within Designated Commands/Units of the United States Marines Corps,” 26 May 2020.
6. Hearing to Receive Testimony on the Posture of the United States Marine Corps before the Senate Armed Services Committee, 117th Congress (2021) (Statement of General David H. Berger, Commandant of the Marine Corps), 3.