Expeditionary Advanced Maritime Operations: How the Marine Corps Can Avoid Becoming a Second Land Army in the Pacific

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The Marine Corps’ very existence rests upon the axiom that the sea is maneuver space — an arena for decisive combat operations. Although the service has been required to spend the last two decades operating as a second land army in Iraq and Afghanistan, these tasks have now changed. As the Marine Corps reorients towards great power competition in the Pacific, it faces the harsh reality that the uncontested maritime maneuver-space it once took for granted — upon which more than $3.4 trillion of annual international maritime trade and America’s most influential companies increasingly depend — is now blanketed with dense layers of Chinese long-range missile weapons engagement zones. Further complicating matters, China now has the world’s largest navy, coast guard, and maritime militia, all of which operate directly under the military chain of command.

Marine Corps Commandant Gen. David Berger’s initial proposed response to this dilemma is expeditionary advanced base operations. This operational concept employs expeditionary systems — emphasizing anti-ship cruise missile launchers — from austere, distributed land bases within adversary weapons engagement zones to contribute to sea control and sea denial operations. A forthcoming Stand-In Forces concept will seek to augment expeditionary advanced base operations by “taking advantage of the relative strength of the contemporary defense” and emerging technologies to create an integrated maritime defense that confronts aggressor naval forces with an array of low signature, affordable, and risk-worthy capabilities. Both concepts emphasize the tactical defense and heavily prioritize capabilities that are either land-based or dependent on land bases within weapons engagement zones. But is a defensively-oriented Marine Corps optimized — either in part or full — for operations ashore really what the U.S. military and policymakers need to compete with and deter Beijing?



Although the Expeditionary Advanced Base Operations concept is viable, it currently envisions a land-based force that is very similar to U.S. Army Multi-Domain Task Forces. The Marine Corps is at risk of once again operating as a second land army, only this time from archipelagos in the Pacific rather than deserts in the Middle East. The service is missing an opportunity to fill a critical military requirement for a low-signature force that can survive in Chinese missile zones and conduct offensive maritime fire and maneuver throughout the littoral seas of the first island chain.

To avoid redundancy with the Army and fill this requirement, the Marine Corps should shift its primary focus to a new concept I propose: expeditionary advanced maritime operations. This concept envisions using small, mobile, lethal, and low-cost capabilities — principles recently highlighted by the commandant — exclusively in the maritime domain. Marine air-sea task forces, the units that would execute this new concept, would consist of marines and sailors employing these capabilities on small boats that sea-base off of motherships, rather than remain tethered to highly vulnerable land bases. These task forces would restore the relevance of the tactical offense to proactively hunt and destroy (or raid and seize) Chinese naval combatants. Such a force would be optimized for conflict in order to credibly deter aggression during “grey zone” competition. By contrast, existing constructs are optimized for competition, which would incentivize an adversary to escalate to conflict. A conflict-optimized force designed for purely sea-based, tactically offensive operations would complement the littoral strike forces proposed by marines in previous War on the Rocks articles, which use primarily land-based small boats, loitering munitions swarms, and elements ashore to create a persistent defense-in-depth that reassures treaty allies and deters Beijing. These “new big idea” littoral strike forces meet the land-based requirements for the expeditionary advanced base operations and stand-in forces concepts, while avoiding redundancy with the Army.

Marines Again a Second Army

The expeditionary advanced base operations concept renders the Marine Corps nearly redundant to Army Multi-Domain Task Forces. The Army envisions Multi-Domain Task Forces in the Pacific “effectively securing airspace and waterways by long-range precision fires or air missile defense” — similar to expeditionary advanced base operations. Last year, in the first modern sinking exercise led by the Army, a Pacific-based Multi-Domain Task Force used shore-based missiles — including a Naval Strike Missile and High Mobility Artillery Rocket System — to sink the decommissioned USS Racine. The Army — like the Marine Corps — wants to use prepositioned sustainment and mobility, concealment, and deception to complicate adversary targeting. Moreover, the Army is planning to increase its sea-denial capacity in the region with a second Multi-Domain Task Force. A war with China would not include a World War II-style island-hopping campaign requiring both Army and Marine Corps land forces, at least not if the U.S. military properly embraces the National Defense Strategy’s deterrence-by-denial foundations. The Army will have sufficient capacity to meet the services’ requirement to deploy missiles to control key sea lanes, especially if it incorporates large numbers of missiles in shipping containers that can be remotely fired. Therefore, U.S. policymakers will not need the Marine Corps to provide additional land-based capacity, as in Iraq and Afghanistan.

This redundancy will inevitably lead to zero-sum interservice battles for relevance and resources that place the two services in competition with each other. This is evident in the Commandant’s Planning Guidance reference to the Army’s rival Multi-Domain Task Forces:

We will test various forms of EABO [expeditionary advanced base operations] against specific threats and ask ourselves whether EABO contributions to the Joint Force are worth its logistics and security burden. This ratio should always be more favorable than other joint force options contributing a similar capability.

The Marine Corps, according to the commandant’s planning guidance, will best the Army in this competition for relevance by relying on its expeditionary capabilities to generate more nimble, lower-signature elements than the Army’s bulkier Multi-Domain Task Forces. In addition to building redundant units, the Army and Marine Corps are also ramping up competition for the same constrained real estate on which to base those forces. Congress already appears concerned, as indicated by the requirement in the 2020 National Defense Authorization Act for the Department of Defense to submit a report that explains the Marine Corps’ and Army’s respective efforts to develop ground-based long-range fires.

Given the countless challenges that exist in the Indo-Pacific, the military needs the Marine Corps to complement the Army rather than duplicate it. Interservice redundancy incurs significant opportunity costs and will impair military effectiveness in both “grey zone” competition and any conflict with China. As a land force, the Army should have primacy over the shore-based sea-denial mission. The Marine Corps has a better option. Although it should continue developing certain niche Expeditionary Advanced Base Operations capabilities, such as advanced naval logistics sites, its real focus should be on becoming an ever more nimble and lethal maritime expeditionary force.

A Small Bear in Alligator Territory

“In the battle between the bear and the alligator, what determines the victor is the terrain.” —Jim Barksdale

Imagine replacing the 2003 march to Baghdad with a float to Baghdad. In this alternative history, the Marine Corps built a force that operated primarily in the Tigris and Euphrates rivers aboard small boats with long-range fires capabilities. Marine Corps leaders could have argued that this littoral force was invaluable for projecting power ashore and controlling key chokepoints — like bridges — to assist the Army with land control and denial operations. Such a force might have made legitimate contributions to the military effort, but the land-dominant terrain would have severely limited its effectiveness and made the Marine Corps a maritime-based alligator in bear territory.

The Marine Corps is not in bear country anymore, and if it wants to hunt in alligator country it needs to move away from land-based concepts and get in the water. The expeditionary advanced base operations concept provides the military with a useful but suboptimal capability for operations in the vast maritime expanse of the Western Pacific. A key distinction of expeditionary advanced maritime operations — expeditionary advanced base operations’ maritime cousin — would be its application of the commandant’s fundamental design principles to a force optimized for operations at sea, rather than ashore. The Commandant’s Planning Guidance says the Marine Corps is, at its essence, “composed of highly capable tactical units that can perform combined arms operations at all echelons, enabled by organic air and logistics.” Expeditionary advanced maritime operations remains faithful to these principles but would rely on marine air-sea task forces with maritime combat elements instead of the traditional Marine Air-Ground Task Force Ground Combat Element. Marine air-sea task forces adapt the Marine Corps’ combined-arms, maneuver-based warfighting approach to the maritime reality of the Pacific region.

Assumes the Superiority of the Defense

The expeditionary advanced base operations concept, as well as what little has been shared about the pending stand-in forces concept, assumes that the tactical defense is the dominant form of contemporary battle and that the littoral seas within the first island chain will become a World War I-style “wartime no-man’s-land (or no-man’s-sea), wherein neither side enjoys assured freedom of movement.” The Expeditionary Advanced Base Operations Handbook states, “In the era of long-range precision weapons, the tactical maritime defense is the stronger form of battle and the greatest challenge to sea control need not come from the sea itself.” This sentiment is echoed by the commandant in his planning guidance. The assumption about the dominance of the tactical defense could be proven false by marine air-sea task force small-boat units that operate as 21st Century maritime “stormtroops,” reviving tactics that restored maneuver and the tactical offense to World War I battlefields and led to World War II “blitzkrieg” attacks. In conflict, this force could use asymmetric, combined-arms blitzkrieg attacks that pierce through China’s Maginot Line of missile weapons engagement zones to hunt adversary ships throughout the littoral seas of the Western Pacific. These task forces would in effect be a new model for Marine Expeditionary Units — a modernized version of the Marine Corps’ historical strength — that restores maritime maneuver to the littoral battlefield.

A Solution: Optimizing the Military for Conflict in the Pacific

The Marine Corps should primarily operate as an asymmetric, sea-based littoral force that employs small boats and high-speed assault craft in mutually supporting combined-arms teams to cripple, raid, and seize Chinese naval combatants. The decisive space in a war with China is the littoral region within the first island chain. China has optimized its military to deny U.S. Navy combatants access to this space. Furthermore, the U.S. Navy surface fleet is a blue-water force designed primarily for operations in the open ocean, and naval warfare in the littorals differs substantially from warfare on the high seas. The military needs a purpose-built asymmetric force designed to survive and conduct fire and maneuver throughout littoral seas within the first island chain. The Commandant’s Planning Guidance describes the Marine Corps as the preeminent littoral warfare service. But the service is heavily focused on capabilities for the landward portion of the littoral region and the Navy does not have the resources to build a littoral force on its own, leaving a critical gap in the seaward portion. An optimized U.S. military would use Army Multi-Domain Task Forces to support sea denial and control from ashore, Navy combatants to dominate the open ocean in the second island chain and beyond, and marine air-sea task forces to “locate, close with and destroy the enemy by fire and maneuver” and help Littoral Strike Forces “repel the enemy assault by fire and close combat” in the littoral seas of the first island chain.

The expeditionary advanced maritime operations concept takes the Continental Marines’ small-boat raiding and ship-to-ship warfighting approach from the 1700s and fuses it with Iran’s modern asymmetric small-boat concept, which continues to bedevil the U.S. Navy. The Chinese blue-water navy is modeled on the current U.S. Navy, so an enhanced version of the Iranian model would prove highly effective against China. Like a boxer fighting a tall opponent with long reach, the main tactical objective of expeditionary advanced maritime operations is to “go inside” and operate in close proximity to Chinese ships, where they are most vulnerable. The Type 055 Renhai cruiser — China’s premier surface combatant — has 112 vertical launch cells capable of firing anti-ship missiles, but these missiles are designed to target large ships at long ranges, not small boats close in. The ship’s one deck gun and close-in weapon system are both forward of the superstructure, making it especially vulnerable to small-boat attacks from the rear. China wants to fight long-range “non-contact warfare,” but expeditionary advanced maritime operations would force it into an up-close and personal fight with U.S. marines and sailors.

Combined-Arms Maneuver Afloat

Figure 1: Notional employment of maritime forces (adapted from Tightening the Chain: Implementing a Strategy of Maritime Pressure in the Western Pacific)

Expeditionary advanced maritime operations would apply the Marine Corps’ traditional combined-arms approach to the maritime domain. Missile boats are analogous to long-range artillery ashore; boats launching loitering munitions swarms have a similar role as mortars; and Mark VI patrol boats with remote-controlled machine guns are similar in function to mobile support-by-fire positions. Marine Corps F-35Bs and drones will provide long-range fires and intelligence support. Surface and aerial fires will target enemy ship propulsion systems, radars, sensors, antennas, and weapons systems while high-speed assault boats filled with reconnaissance and specially trained infantry Marines — teamed with special operations forces — swarm the ship and assist with its destruction. If conditions permit, assault teams could board the ship, seize the bridge, capture key personnel and material of intelligence value, and — if propulsion systems can be restored — commandeer the ship and bring it back to a friendly location for exploitation. A right-sized infantry battalion could take down a group of three Chinese ships.

Lethal, Agile, and Cost-Effective

Marine air-sea task forces would substitute traditional Marine Air-Ground Task Force ground vehicles with small boats and assault craft. The Navy’s Mark VI has a range of over 600 nautical miles, a sprint speed of up to 45 knots, and the ability to survive in sea state four — the highest weather conditions in the South China Sea. These boats cost around $8.6 million, similar to the expected cost of one Armed Reconnaissance Vehicle. With the $87 million cost of one CH-53K heavy-lift helicopter — an unnecessary platform for this new concept — the Marine Corps could purchase 10 Mark VI platforms. Mark VIs could be modified to carry an unusually diverse array of weapons, including torpedo tubes, mines, anti-air systems, unmanned underwater vehicles, or launchers for loitering munitions swarms.

In 2017, Lockheed Martin showcased a scale-model of an unmanned Mark VI fitted with four Long Range Anti-Ship Missile tubes. This capability’s superior maneuver range and agility compared to land-based missile launchers would make it more survivable and easier to resupply, enable it to self-deploy from motherships to operating locations, and complicate Chinese ships’ ability to know when they were within missile zones. Manned Mark VIs could act as quarterbacks, conducting Manned-Unmanned Teaming operations with unmanned Mark VIs or multiple Common Unmanned Surface Vessels operating in a reconnaissance or screening role. These vessels have double the range of the Mark VI and a large payload bay. A cost-effective variant of the Combatant Craft Medium, which has a top speed of 52 knots and the same range as the Mark VI, would enable the Marine Corps to rapidly close with enemy ships during assaults. Owning small vessels would not be entirely new for the Marine Corps. In the 1990s and early 2000s, the service had standing small-craft companies. Marine air-sea task forces would revive and enlarge an organizational structure that is already in the Marine Corps’ historical DNA.


Figure 2: Notional force structure for expeditionary advanced maritime operations

Sea-Based Sustainment

Marine air-sea task forces would minimize reliance on vulnerable land bases in the first and second island chains by integrating with the Navy for sea-based logistical sustainment. This would free the task forces from host-nation constraints, whereas expeditionary advanced base operations require host-nation approvals that could be withheld if a country wishes to avoid the pitfalls of involving itself in a U.S.-China conflict. Marine air-sea task forces would rely on a mix of military sealift command vessels, modified amphibious assault ships, expeditionary fast transports, and offshore support vessels as sea-basing and logistical sustainment platforms. U.S. Special Operations Command’s M/V Ocean Trader is an excellent example of a vessel optimized to support small boats. Multiple ships like the M/V Ocean Trader could be purchased for the price of a single San Antonio-class amphibious assault ship. These large motherships would remain outside weapons engagement zones, while smaller and more numerous expeditionary fast transports and offshore support vessels use maneuverability and minimized electronic emissions to survive and operate within these zones as forward arming and refueling points for Marine Corps small boats. Pushing munitions and fuel directly from maritime nodes to missile-boats would be more efficient, take less time, and create a smaller signature than pushing it ashore to trucks — via beaches or harbors — for follow-on transport to land-based missile-launchers.

The Way Ahead for Avoiding Redundancy and Reclaiming the Offensive

The expeditionary advanced base operations concept makes the Marine Corps a second land army and fails to optimize the military for a conflict with China in the Pacific. Alternatively, the expeditionary advanced maritime operations concept would position the Marine Corps as an asymmetrically mobile force uniquely adapted for seaborne operations. This, in turn, would force China to adapt its concepts and force structure in response, placing it into a defensive and reactive posture that would allow the United States to dictate the course of events. The Marine Corps should accelerate experimentation with various small boats equipped with diverse sensors and weapons systems and should wargame concepts that weave these capabilities together to generate combined-arms effects that paralyze China’s navy. The platforms and most of the weapons systems required to make this concept a reality already exist, and makeshift motherships and boats with capabilities like anti-ship missiles could be obtained by 2025.

The tactical defense has always been the stronger form of battle — that reality is woven into the very nature of war — but it is by no means dominant and has never been the decisive form of battle. The defense “should be used only so long as weakness compels.” This new concept will enable the Marine Corps to go on the offensive. The service’s legacy and identity is as a force of offensively-oriented shock troops prepared to violently overrun enemy defenses on behalf of the nation. This new concept rediscovers the service’s historical identity in the Pacific. The expeditionary advanced maritime operations concept would be an important step for the Marine Corps — both back to its roots and toward readiness to take the fight to a littoral opponent.



Maj. Jake Yeager is an intelligence officer currently assigned to I Marine Expeditionary Force. The opinions expressed here are the author’s alone and do not necessarily represent the U.S. Marine Corps or Department of Defense.

Image: DVIDS (photo by Cpl. Matthew Teutsch)