Marines Need the Maritime Prepositioning Force More Than Ever

Of the many concerns Commandant of the Marine Corps General David H. Berger outlines in his 38th Commandant’s Planning Guidance, one with immediate effects on current operational plans is the need to update and harden the Maritime Prepositioning Force (MPF). MPF consists of two parts: the ships of the Maritime Prepositioning Squadrons (MPSRONs) and the gear and equipment loaded on them. The problem, in General Berger’s words, is that “during a major contingency, our MPF ships would be highly vulnerable and difficult to protect.”¹

These large, aging ships are more akin to commercial cargo ships than warships. Even when new, they were never designed to survive naval combat. Before the release of the Commandant’s Planning Guidance, thinkers across the Marine Corps were openly asking if the MPF still provided a competitive advantage to the Marine air-ground task force (MAGTF) or was no longer relevant. The two key words in this question are relevant and competitive.

For the purposes of this argument, relevance will be defined as viability; that is, the probability that MPF assets will be able to survive and be capable of delivering equipment to where it is useful. As defined in the recently published Marine Corps Doctrinal Publication (MCDP) 1-4, Competing, competition is defined as “the wide spectrum of struggle that takes place between ‘peace’ and ‘war.’”² In other words, actions that are directly or indirectly taken against an adversary below the threshold of violence.

Theater Specific

The degree of the MPF’s relevance depends on the theater of operations. There is a fundamental difference between an MPF concept of employment in a European theater conflict with the Russian Federation and that of a western Pacific theater conflict with the People’s Republic of China. MPF ships can surge equipment to friendly ports (which, thanks to NATO, are numerous) not under threat and reach the joint area of responsibility via the extensive rail and road networks of Europe. In the western Pacific, virtually all ports from which equipment can be forwarded to units in the blunt layer are within the weapons engagement zone (WEZ) of Chinese sensors and long-range precision fires. Furthermore, the absence of a NATO analog in Southeast Asia means that friendly ports are far less plentiful than in Europe, at least for immediate access. In a conflict with the Russian Federation, even non-NATO European states in Europe are likely to side with NATO; in a conflict with China, neutral states are more likely to stay neutral, and some will even side with Beijing.

However, MPF operations in the western Pacific still have relevance. As demonstrated during Exercise Trident Juncture 18 in the North Atlantic, the larger, more vulnerable MPSRON container ships can be used to “cross-deck prepositioned equipment in friendly ports outside the enemy’s weapons engagement zone to smaller vessels, or even amphibious ships, if they provide operational advantages like a shallower draft, greater force protection, or quantities that complicate adversary targeting.”³ Used this way, even the outdated MPSRON platforms would reduce the strain on other U.S. Transportation Command strategic mobility assets and getting needed equipment to the theater faster, while minimizing the risk to the largest, most vulnerable ships. Furthermore, exercises such as Trident Juncture in the European Command area of responsibility and Freedom Banner in the Indo-Pacific Command area of responsibility have demonstrated that even the MPSRON in its current state does not completely depend on fixed-port facilities. Instead, it can execute what is known as “in-stream” offloads of equipment from the container ships to various over-the-shoreline connectors. Thus, Marine Colonel John Sullivan observed that Trident Juncture 18 “demonstrated maritime prepositioning ships possess the mobility, capacity, versatility, and range to conduct ‘operational maneuver’ in preconflict scenarios.”⁴ One can imagine conditions under which a MAGTF or joint force commander would assume the risk of conducting such an operational maneuver in a conflict scenario, as well.

Recalculating Risk

That said, it is difficult to argue with Colonel Sullivan’s assertion, echoed in the Commandant’s Planning Guidance, that “if MPF operations are to hold relevancy for future conflicts, their original risk margins have to be re-envisioned or mitigating actions taken.”⁵ Yet as MCDP 1-4 and the Joint Concept for Integrated Campaigning explain, conflict and competition are distinct concepts. Whichever term or phrase one prefers—competition, preconflict, “persistent Phase Zero shaping,” etc.—the amount of risk that can be assumed while protecting the MPF in preconflict is different than in violent conflict with a peer competitor. Below the threshold of war, the MPF (even in its current state) can give the MAGTF a significant competitive advantage when used to enable theater security cooperation activities, bi- and multilateral training exercises, and humanitarian assistance missions. The Marine Corps uses rotational units to conduct most of these activities.

Without MPF, the service would not be able to train with the full range of Marine Corps equipment in places such as the Republic of Korea, Southeast Asia, Norway, or the Black Sea. Without the MPF, the ability of the Third Marine Expeditionary Force (III MEF) to conduct humanitarian assistance/disaster relief (HA/DR) missions in the most natural disaster–prone region on Earth would be limited to the 31st Marine Expeditionary Unit’s at-sea periods. These two missions form the bulk of the Marine Corps’ contribution to competition against peer and near-peer adversaries. As MCDP 1-4 explains,

We conduct exercises in part to demonstrate that the United States has a military capability it could use if necessary. The existence of these capabilities can impose cost on a potential rival, because the rival may need to expend resources if they want to overcome or negate a US competitive advantage.⁶

To put it differently, MPF is still relevant because it still enables operational maneuver. And it affords a competitive advantage because it allows the Marine Corps to demonstrate this operational maneuver capability in full view of U.S. adversaries, who must now grapple with the possibility that the United States can project power on short notice and without depending on fixed-port facilities. In the case of HA/DR, it allows units to get help to the scene as fast or faster than U.S. rivals can (even though the U.S. homeland is usually much farther away), assuring partners and neutral actors of U.S. goodwill and capability.

The MPF is no doubt in need of renewal, upgrade, and increased investment, but it is not irrelevant. In fact, as the Marine Corps divests of legacy capabilities and awaits the development of new ones necessary to operate according to the naval concepts of distributed maritime operations (DMO), littoral operations in the contested environment (LOCE), and expeditionary advanced base operations (EABO), the MPF may be more valuable for competition now than at any point since the end of the Cold War. During this time of transition, the Marine Corps cannot afford to lose proficiency at conducting MPF operations.