The U.S. Navy’s Amphibious Assault Renaissance: It’s More Than Ships and Aircraft


Editor’s Note: This article is a part of our series on the roles and missions of the U.S. armed services.

Over the summer, the Smithsonian Channel featured a series, The Pacific War in Color.  Amphibious assaults on Japanese-held islands, such as Tarawa, Peleliu, Iwo Jima, Okinawa, and others were a prominent part of the program. Viewers witnessed armadas of amphibious ships and hundreds of landing craft that were part of each forcible-entry operation where an attacking force needed to come ashore in the face of significant opposition.

In the post-Cold War era, amphibious assault forces have not been the most capable part of the U.S. Navy. In the years after 9/11 — while the Marine Corps was engaged in Iraq and Afghanistan and not embarked in amphibious ships — the amphibious-assault fleet was, at best, an afterthought. Today, the Marine Corps is largely disengaged from land-centric conflicts and, in a move spearheaded by two former commandants, is “returning to its amphibious roots,” signaling a new emphasis on amphibious warfare.

This renaissance in America’s amphibious assault force has been chronicled in various publications, especially War on the Rocks. As David Fuquea put it in an article in this outlet five years ago, “Employing U.S. military forces in the 21st Century will require introducing combat forces across unimproved beaches or terrain on a potentially hostile shore.”

According to Lt. Gen. David Berger, commander of the Marine Corps Combat Development Command, “We need to be prepared for large-scale amphibious operations.” He continued, speaking to the sold-out National Defense Industrial Association Annual Expeditionary Warfare Conference, “We might do it differently in the future, but we can’t ignore it.”

Other articles in War on the Rocks have reinforced the opinion that Navy-Marine Corps amphibious forces will be a critical element of America’s strategic calculus in the 21st century. We encourage readers to revisit articles on amphibious assault by Brett Friedman, B.J. Armstrong, and Bryan Clark and Jesse Sloman. Critically, these authors called for innovative technologies to support U.S. amphibious forces as they deal with increasingly capable adversaries.

An article by Col. Clifford Weinstein in Marine Corps Gazette highlighted Marine thinking on future amphibious assault operations:

While forcible-entry operations are often thought of exclusively in terms of initiating a continental campaign, an application some analysts assume to be unlikely, it may be more probable in the 21st century that they are conducted as part of a joint campaign that is maritime in character. It ought to be self-evident from looking at a map that military competition in the near seas will involve an amphibious component — to include amphibious assault when and where required.

The Gazette article goes on to note that “a film about a modern amphibious operation would likely be boring, as there would be no dramatic scenes of large units fighting their way across a heavily defended beach.” Indeed, the Navy and Marine Corps have been developing more indirect approaches to move from ship to shore.

The indirect approach is exemplified by the operations of Task Force 58 — an integrated Navy-Marine Corps formation commanded by then-Brig. Gen. James N. Mattis. In 2001, multiple maneuver elements embarked on the USS Peleliu and the USS Bataan projected 350 miles inland to seize an airstrip south of Kandahar. Additional forces were introduced from that airstrip, renamed Forward Operating Base Rhino, leading to the seizure of the city. By definition, Task Force 58 constituted “forcible entry,” even though it bore no resemblance to the invasions of Normandy or Inchon.

Current U.S. Navy and Marine Corps operations suggest the sea services are training in the way they intend to fight. As reported by USNI News, Exercise Trident Juncture, involving 50,000 personnel, 65 ships, 250 aircraft, 14,000 American troops, and a carrier strike group, centered around a scenario of protecting Norway from an invasion by inserting reinforcements by air and amphibious landing. The exercise culminated with a force of U.S. marines pushing ashore with 12 amphibious assault vehicles, six light armored vehicles, and 21 Humvees. Maj. Gen. David Coffman, director of expeditionary warfare in the Office of the Chief of Naval Operations, described amphibious ships’ usefulness to combatant commanders as a multiplication problem: “capacity times capability times readiness equals lethality.”

These changes to the Navy’s amphibious assault forces are occurring at a time of rapid technological change in the platforms the service fields. There is little question that unmanned systems are one of the technologies having a profound impact on naval operations. Indeed, three recent  Navy-commissioned studies recommend more unmanned systems in the Navy and Marine Corps inventories.

The conflicts in Iraq and Afghanistan have spurred the development of unmanned aerial vehicles and unmanned ground vehicles to meet operational needs. Unmanned maritime vehicles (both surface and subsurface) have not received the same emphasis or funding. The renaissance of the Navy’s expeditionary assault forces and its embrace of unmanned systems are intersecting in ways that promise to significantly change the way the service and the Marine Corps fight in the 21st century.

America’s Expeditionary Forces: Business Is on the Upswing

For decades, when a crisis emerged anywhere on the globe, the first question a U.S. president asked was, “Where are the carriers?” Today, that question is still asked, but increasingly, it has morphed into, “Where are the expeditionary strike groups?” The reason for this is clear: These naval expeditionary formations — built around a large-deck amphibious assault ship, an amphibious transport dock, and a dock landing ship — have been the ones used extensively for a wide array of missions short of war, from anti-piracy patrols, to personnel evacuation to humanitarian assistance and disaster relief. And where tensions lead to hostilities these forces are the only ones that give the U.S. military a forcible-entry option.

U.S. naval expeditionary forces have remained relatively robust even as the size of the Navy has shrunk from a high of 594 ships in 1987 to 272 ships in 2018. Naval expeditionary strike groups comprise an important part  of the current fleet. Indeed, the blueprint for the future fleet the Navy is building, as seen in a recent Congressional Research Service report, maintains — and even increases — that percentage. The service’s annual shipbuilding projections have articulated this commitment to meet the Navy’s longstanding requirement for 38 amphibious force ships.

However, ships are increasingly expensive, and Navy and Marine Corps expeditionary forces have been proactive in looking to affordable new technology to add capability to their existing and future ships. One of the technologies that offers the most promise in this regard is unmanned systems. These unmanned systems can reduce the risk to human life in high-threat areas, deliver persistent surveillance over areas of interest, and provide options to warfighters — particularly given their ability to operate autonomously.

The Navy and Marine Corps have a wide array of unmanned aerial systems currently in their respective fleets or coming on line: the MQ-4C Triton, the MQ-8 Fire Scout, the MQ-1 Predator, the MQ-9 Reaper, the MQ-25 Stingray, and others. These capable assets are primarily used for theater-level surveillance (Triton), carrier strike group support (Fire Scout and Stingray), or supporting troops in the field (Predator and Reaper). There are few unmanned systems dedicated to the Navy-Marine Corps expeditionary forces while they are at sea or in the assault phase of an operation. That is beginning to change in profound ways.

Testing and Evaluating Unmanned Systems to Support Expeditionary Strike Groups

The Navy-Marine Corps team has sought to test and evaluate unmanned systems to add capability in the ship-to-shore maneuver and assault phase of their operations. Appropriately, this new technology insertion has primarily focused on supporting marines in the fight on the ground. Articles in this publication on the “Guardian Angel” and Warbot concepts have addressed the pros  and the cons  of current Navy and Marine Corps planning in this area, especially in regard to unmanned vehicles.

That said, there is one area that has not received as much attention regarding leveraging unmanned systems to support the Navy-Marine Corps amphibious team: gathering intelligence of the objective area — typically a defended port or beach — prior to an amphibious assault or raid. This is a critical aspect of any expeditionary operation. Part of the reason for this lack of emphasis may be the more compelling need to support marines on the ground and in the fight. Another reason is that the unmanned technologies needed to perform this intelligence-gathering have not, until recently, been mature enough to perform this mission. That is changing.

The reason for embracing unmanned systems and the sensors they carry to perform this mission is straightforward. Instead of having marines, sailors, or special operators gather intelligence — thereby putting them at high risk — unmanned systems offer commanders a way to keep warfighters safe while performing these critical missions.

For this reason, the Navy-Marine Corps expeditionary forces have been active in evaluating a wide variety of unmanned systems in various exercises, experiments, and demonstrations — especially unmanned surface vehicles. These platforms are especially adept at conducting intelligence, surveillance, and reconnaissance missions. They typically better suited for these missions than their aerial counterparts for several reasons, particularly their ability to remain undetected by enemy sensors, as well as their dwell time on station. By performing near-shore intelligence preparation of the battlespace, unmanned surface vehicles increase the standoff, reach, and distributed lethality of the manned platforms they support by providing the assault force with detailed information of the area where marines will be going ashore.

Navy-Marine Corps expeditionary forces recently tested new technologies in the Ship-to-Shore Maneuver Exploration and Experimentation Advanced Naval Technology Exercise (commonly called S2ME2) and the Bold Alligator exercise. These events demonstrated the potential of unmanned naval systems to be force multipliers and critical enablers for expeditionary strike groups. The former exercise focused on identifying gaps in capabilities that advanced unmanned maritime systems might close. One area singled out for special emphasis was the critical intelligence, surveillance, and reconnaissance mission needed before conducting the amphibious ship-to-shore operation. This exercise focused on unmanned systems — especially surface systems — that could provide real-time intelligence on the battlespace prior to and during an amphibious assault or raid.

During the assault phase of the exercise, the Navy-Marine Corps expeditionary force used an unmanned surface vehicle to thwart enemy defenses. The expeditionary commander launched an eight-foot MANTAS unmanned surface vehicle (one of a family of stealthy, low-profile, unmanned surface vehicles) to provide intelligence, surveillance, and reconnaissance of adversary positions. The vehicle swam undetected into the enemy port (the Del Mar Boat Basin on the southern Californian coast) and relayed information to the amphibious force command center using its command-and-control system.

Once this larger-scale intelligence, surveillance, and reconnaissance mission was completed, the operational commander needed to determine more granular information before launching waves of assault craft. For this effort, the MANTAS unmanned surface vehicle was driven to the surf zone to provide information crucial to planners. This included obstacle location (especially mine-like objects), beach gradient, and other factors to determine whether the hazards involved could be mitigated to the extent that the assault should go forward.

In an interview in Chips Online, one of the exercise’s organizers explained how unmanned systems supported the intelligence, surveillance, and reconnaissance and intelligence preparation of the battlefield missions:

We use the Navy’s organic labs and warfare centers to bring together emerging technologies and innovation to solve a specific problem. It’s focused on unmanned systems, with a big emphasis on intelligence gathering, surveillance, and reconnaissance.

Tracy Conroy, SPAWAR Systems Center Pacific’s experimentation director, highlighted the importance of having unmanned systems perform this critical — and inherently dangerous — task, explaining, “The innovative technology of unmanned vehicles offers a way to gather information that ultimately may help save lives. We take less of a risk of losing a marine or Navy SEAL.”

This exercise was a precursor to another major Navy-Marine Corps expeditionary exercise, Bold Alligator. This live exercise demonstrated maritime and amphibious force capabilities and focused on planning and conducting amphibious operations, as well as evaluating new technologies that support the expeditionary force, especially readily available commercial off-the-shelf technology.

The 2nd Marine Expeditionary Brigade directed scenario-driven events during Bold Alligator. The command element was embarked in three amphibious ships: USS Arlington, USS Fort McHenry, and USS Gunston Hall. In addition to the brigade’s primary mission of a major amphibious assault, there was a significant secondary mission of attacking adversary positions along the Intracoastal Waterway.

The early phases of Bold Alligator were dedicated to long-range reconnaissance. Operators at the exercise command center at Naval Station Norfolk drove the six-foot and 12-foot MANTAS unmanned surface vehicles off North and South Onslow Beaches, as well as up the Intracoastal Waterway. Both unmanned surface vehicles streamed live, high-resolution video and sonar images to the command center. The video images showed vehicles, personnel, and other objects on the beaches and in the Intracoastal Waterway.

The 2nd Marine Expeditionary Brigade used a12-foot MANTAS, equipped with a gyro stabilized camera and a forward-looking imaging sonar, to provide critical intelligence just prior to the ship-to-shore amphibious assault. The sonar images provided surf-zone bottom analysis and located objects — especially mines — and other obstacles that could present a hazard during the assault phase.

Bold Alligator underscored the ability of surface unmanned systems to provide real-time intelligence, surveillance, and reconnaissance. This capability is crucial in amphibious operations to ensure that a landing or other craft could successfully navigate a waterway or enter the surf zone without encountering mines or other objects. Clearing a path for a vehicle or vessel to safely pass through the surf zone and onto the beach during an assault is the make-or-break factor for any amphibious operation.

From a mission command perspective, having the ability to view images of adversary positions and emplacements — both above and below the water — in real-time enables decision-makers not on scene to make time-critical determinations and balance the importance of the mission with the risks to operators. The value of providing commanders with real-time intelligence, surveillance, and reconnaissance is difficult to overstate, and it is likely that the Navy/Marine Corps will continue to examine this capability in other expeditionary exercises going forward.

Fielding Unmanned Maritime Systems Faster

One of the major challenges to the Navy making a substantial commitment to unmanned maritime systems is the fact that they are relatively new and their development has been under the radar for all but a few professionals in the research and development, requirements, and acquisition communities. That is now changing.

The Naval Sea Systems Command and Navy laboratories have been accelerating the development of unmanned maritime vehicles. The Navy has partnered with industry to develop, field, and test a family of these platforms, such as the Medium Displacement Unmanned Surface Vehicle, MANTAS next-generation unmanned surface vessels, the Large Displacement Unmanned Underwater Vehicle, and others. As described in a recent U.S. Naval Institute Proceedings article, this includes the COTS Mk18 Mod1/Mod2 unmanned vehicles that are key to the Navy and Marine Corps Expeditionary Mine Countermeasures Company concept.

Indeed, testing has been so successful that the Department of the Navy has begun to provide increased support for unmanned maritime vehicles and has established program guidance for many of the systems important to the Navy and Marine Corps. This commitment to unmanned systems programs is reflected in the Navy Program Guide as well as in the 2018 Marine Corps Concepts and Programs publications.

Capt. Jon Rucker, then-program manager of the Navy program office with stewardship over unmanned maritime systems, discussed his programs with USNI News. The title of the article, “Navy Racing to Test, Field, Unmanned Maritime Vehicles for Future Ships,” captured the essence of where unmanned maritime systems will fit in tomorrow’s Navy, as well as the Navy-after-next. Rucker shared:

In addition to these programs of record, the Navy and Marine Corps have been testing as many unmanned vehicle prototypes as they can, hoping to see the art of the possible for unmanned systems taking on new mission sets. Many of these systems being tested are small surface and underwater vehicles that can be tested by the dozens at tech demonstrations or by operating units.

While the Navy is committed to several programs of record for large unmanned maritime systems such as those described above, the Navy also sees great potential in expanding the scope of unmanned maritime systems testing:

Rucker said a lot of the small, unmanned vehicles are used to extend the reach of a mission through aiding in communications or reconnaissance. None have become programs of record yet, but [Rucker’s office] is monitoring their development and their participation in events like the Ship-to-Shore Maneuver Exploration and Experimentation Advanced Naval Technology Exercise, which featured several small UUVs [unmanned underwater vehicles] and USVs [unmanned surface vehicles].

The ship-to-shore movement of an expeditionary assault force remains the most hazardous mission for any navy. Real-time intelligence, surveillance, and reconnaissance will spell the difference between mission success and failure — and failure means the loss of life. For this reason, the Navy and Marine Corps team is, indeed, racing to field unmanned maritime systems, and especially unmanned surface systems, to directly support U.S. expeditionary forces (See Figure 1).

This commitment to unmanned maritime systems opens up new strategic, operational, and tactical possibilities for expeditionary strike groups. As pointed out by Douglas King and Brett Friedman in their War on the Rocks article, “Distributed Maritime Operations and the Modern Littoral Environment,” small, inexpensive connector vessels can be used to carry a large number of unmanned maritime systems toward a given area, keeping billion-dollar amphibious ships further offshore and out of the range of adversary defensive systems.

The Department of the Navy should make a strategic shift in its stewardship of unmanned systems. The recent actions of establishing — then standing down — two offices focused on unmanned systems, one at the secretariat level, and the other at the chief of naval operations staff level, is behind us. Now that unmanned systems are being mainstreamed (again), it is time to focus on developing and fielding unmanned systems that directly support Navy and Marine Corps warfighters. It is clear to us that the increased emphasis on unmanned surface systems is long overdue.


A naval aviator, Capt. George Galdorisi had three tours in the amphibious-assault Navy, including command of the USS Cleveland and Amphibious Squadron Seven. Dr. Scott Truver manages Gryphon Technologies’ naval and maritime programs and serves as senior advisor at the Center for Naval Analyses.

Image: U.S. Navy photo by Mass Communication Specialist 3rd Class Taylor King