The Stand-In Force Needs Sea Legs

The Marine Corps’ Force Design 2030 and complementary conceptual frameworks such as A Concept for Stand-in Forces describe promising solutions to the challenges of the current and emerging operating environment. Among these solutions, the stand-in force is a viable means to counter adversary actions across the competition continuum. However, the units designed to accomplish this, such as the Marine Littoral Regiment (MLR), are woefully unprepared to operate effectively as “small but lethal, low signature, mobile, relatively simple to maintain and sustain forces . . . within a contested area as the leading edge of a maritime defense-in-depth.”¹ Currently fielded transportation platforms lack the mobility and lethality necessary to insert these forces over the sea to key terrain, maneuver within the restricted maritime environment of China’s first island chain, and persist while enabling the tasks envisioned by A Concept for Stand-In Forces.

For the stand-in force to succeed, the MLR must be task organized with fast assault craft such as the CB90 or Mk VI.

A Mobility and Sustainment Shortfall

A Concept for Stand-in Forces largely overlooks the importance of inserting forces in contested terrain undetected, asserting that entry into and persistence within an adversary’s weapons engagement zone (WEZ) can be achieved through host-nation support and consistent forward operations with allies and partners.² This does little to generate uncertainty regarding unit locations and presents the adversary starting points from which it can direct collections efforts. The MLR needs platforms that will enable it to enter the WEZ with a low probability of detection.

Current ship-to-shore connectors leave the MLR vulnerable as it enters the WEZ. Large surface vessels, while possessing greater capacity for Marines and their equipment, are too large, slow, and easily targeted.³ The sinking of the Russian warship Moskva by Ukrainian Neptune missiles is a sobering reminder of the significant risks to large vessels operating within an adversary’s WEZ.⁴ The MV-22, with its remarkable speed and range, is a capable option for aerial insertion; however, landing zone requirements restrict its utility in the densely vegetated terrain of the first island chain. In addition, adversary ship- and ground-based radars can identify markers for the aircraft to cue additional reconnaissance and surveillance assets that could compromise or target the MLR. Smaller platforms such as the amphibious combat vehicle (ACV) or combat rubber reconnaissance craft (CRRC), while benefiting from reduced signature, lack the necessary range and are too slow in the water to rapidly penetrate defensive bubbles.⁵

Once inside the WEZ, the MLR also must be able to “move on the seaward side of the littorals as easily as on the landward side.”⁶ Aside from the ACV, existing platforms do not provide substantial maneuver capability, either landward or seaward, and are not organic to or tasked by the MLR once the force is inserted. In the restricted terrain of the first island chain, the MLR has no organic means to capably relocate to new positions of advantage, maintain target custody of adversary assets, conduct multimodal reconnaissance, or support logistics requirements, especially over the water.

Reliance on external sources for delivery and sustainment limits resupply options and risks compromise from airdrops and link-ups with large support vessels. The enemy could determine how and where forces are maneuvering once inserted and be able to collect on and disrupt supply chains and logistics networks required for their sustainment.

The MLR also lacks the organic weapons to deny the enemy freedom of action at sea or defend against seaward threats.⁷ Given the proliferation of adversary small boats and maritime militias, the MLR will encounter these relatively low-value targets with increasing frequency.⁸ Providing external air or naval support will require unmasking higher-value capabilities, such as naval surface fire support and close air support, leaving those capabilities vulnerable to targeting. While organic precision fires, ACVs, and organic infantry weapons provide localized security and ground-based fires, they are best suited for land-based targets and will be constrained by restrictive jungle terrain.

Bridging the Gap

Fast assault craft such as the CB-90 or Mk VI could bridge the gap in speed, versatility, capacity, and signature, allowing the MLR to insert, persist, and operate as a stand-in force within the adversary’s WEZ. The CB-90, for example, can transport 21 Marines at speeds in excess of 40 knots up to 300 nautical miles (nm).⁹ With their small footprint, fast assault craft could insert a significant number of combat-loaded Marines to key maritime terrain while being embarked on board an LHA.¹⁰

Unlike other low-signature options such as the CRRC, fast assault craft have greater troop-carrying capacity and speed, requiring fewer vessels and less time to accomplish insertion. Their mobility also enables maritime patrolling and reconnaissance and counterreconnaissance within littoral terrain that is inaccessible to large vessels. For the MLR, this mobility enables more frequent relocation, increases opportunities for local reconnaissance and security, and disperses logistical support to create a more resilient supply network. With organic maritime mobility, the MLR could link up with support vessels, resupply at expeditionary advanced bases or cache sites, and retrieve air drops from a greater number of locations to create more robust and diverse sustainment channels.

In addition, fast assault craft can be outfitted with weapons, optics, and electronics suites that would give the MLR the ability not only to defend itself, but also to conduct counterreconnaissance unbound by landward terrain.¹¹ This would preserve higher-value ship-killers and extended-range missile systems, enabling them to unmask only for targets of significant value. Moreover, though larger platforms such as the LAW or LCAC are not suitable for MLR insertion, they are required to get precision fires, missiles, radar systems, and other capabilities ashore. An MLR armed with small attack craft can insert ahead of these larger vessels, prepare to receive them, and provide security both in transit and during offload. As the Congressional Research Service has noted, the intended singular employment of a larger and more expensive ship such as the LAW creates vulnerabilities; small attack craft can limit some of those vulnerabilities.¹²

Potential Obstacles

Because the viability of the stand-in force largely depends on remaining unseen, planners cannot ignore concerns that small craft will generate significant logistical and maintenance requirements for the MLR. However, current platforms such as the LCU or LCAC already are difficult to maintain and require “home” vessels for retrieval should they become inoperable.¹³ The mobility afforded by small craft, with redundancy provided by the three or four vessels that would support a platoon, enables greater access to logistics hubs, cache sites, and expeditionary advanced bases for fuel, parts, and maintenance.¹⁴ In concert with the expeditionary advanced base concept, logistical nodes positioned forward would help address maintenance and sustainment for these vessels.¹⁵

User-level maintenance training also would enable limited serviceability that would extend operating horizons and limit required transits to hubs. In extremis, deadlined craft can be cannibalized to support remaining vessels.¹⁶

It could also be argued that additional vessels contribute to a larger footprint, and increased movement in itself could compromise the stand-in force. A Concept for Stand-in Forces notes how the reward of additional mobility exceeds the risk:

Hard to kill refers to making it difficult for an adversary to target [stand-in forces] by understanding how the adversary performs targeting, and then negating those efforts through movement, dispersion, and by defeating the sensors themselves. For example, as [stand-in forces] learn how a potential adversary’s space capabilities collect on a forward position, they establish a displacement schedule to change locations after each overflight of a sensor. By operating distributed, [stand-in forces] make it difficult for an adversary to decide how to apportion collections and targeting resources.¹⁷

If the MLR is restricted to the ground mobility provided by MRZR light tactical vehicles, joint light tactical vehicles, or ACVs, an adversary will first look along readily identifiable mobility corridors to locate the force. Interisland mobility creates additional options that will stress adversary collections, disrupt their reconnaissance efforts, generate uncertainty, and increase costs in time and resources. While more vessels may increase the footprint, the additional mobility can be used to create an ambiguous situation for the adversary, which in turn protects the MLR.

A Concept for Stand-in Forces requires a force with “sufficient organic maneuver and offensive capability to gain a position of advantage by securing, seizing, and controlling contested key maritime terrain in support of sea denial operations.” An MLR task organized with fast assault craft such as the CB-90 or Mk VI is this force.