The US Army has reevaluated the international threat landscape and responded by committing to the doctrine of Multi-Domain Operations (MDO). The evolution of the MDO concept resulted in the recent update to Field Manual (FM) 3-0, Operations in October 2022, which notably devotes an entire chapter to “Army Operations in Maritime Environments.” In so doing, the Army has shown a dim but dawning realization that its anticipated future of exposure to shipborne threats necessitates a capability long believed to be outdated. That capability is destroying maritime assets from the shore. In short, coast artillery.

The Army’s prioritization of the development of long-range precision fires, and in particular Strategic Mid-Range Fires, has reintroduced the dormant idea of surface-to-ship fires. Although this capability is on its 2030 horizon, the Army’s organizational culture and institutional thinking are slow to grasp the import of kinetically striking ships from shore.

In embracing MDO the Army continues to put lopsided emphasis on the cyber and space domains and the electromagnetic spectrum, presuming that the integration of the mundane domains of land, air, and sea has already been accomplished. Particularly for the Army this is not the case. The maritime domain and its interrelationship with the land domain, for example, is mystery. Joint interoperability with the US Navy has been nearly totally ignored for decades—arguably since the end of World War II. But as the Army continues its pivot to preparing for large-scale combat operations and seeks ways to contribute to US strategic competition activities, it must undergo a radical change of both capability and mindset to remain a relevant and effective part of integrated deterrence.

Instead of viewing surface-to-ship fires as a sideshow capability to the sexier science-fiction domains married up at the boutique Multi-Domain Task Force level, the Army should place primacy on the coast artillery role. This calls for the reanimation of a modern Coast Artillery Corps.

The Demise of the Original Coast Artillery Corps

Up through World War II guarding the shore from attack by ship was a fundamental component of US national defense strategy, and a significant amount of limited defense resources were dedicated to the US Army Coast Artillery Corps. As inconceivable as it may seem now, just a century ago heavy (coast) artillery units and assets were significantly more numerous than those of light (field) artillery.

Beginning with World War II, the comparatively overwhelming might of the US Navy and the advent of long-range strategic airpower facilitated a doctrinal shift that characterized US defense the second half of the twentieth century. The United States would thenceforth achieve an unchallenged static defense of home territories by employing an active offensive capability that would be defined by overseas basing and forward operations. The risk of a sea invasion on the Atlantic or Pacific continental coasts was increasingly regarded as so fantastic that the very idea of a need to defend the land from attack by sea atrophied and eventually disappeared. The oceanic distances surrounding the North American continent were too immense, and the US Navy too powerful and globally present to conceivably be challenged by a rival naval force.

For three-quarters of a century, the United States has been able to wage limited-scope military conflicts throughout the world without having to provide significant combat power to protect its lines of communication. However, this reliance on overwhelming naval dominance, in conjunction with a fortuitous geographical location buttressed by massive oceans, has caused the United States to develop an operational perspective like that of the Athenians at the onset of the Peloponnesian War. Athens had walls and went to war believing that its navy, coupled with its extensive Delian League allies all around the Aegean Sea, would ensure that the war would be fought beyond its frontiers. This perspective held—until Sparta was able to defeat the Athenian navy and then capture the city of Athens.

The United States has neglected the need for deliberate static defensive measures. It has relied on the belief that naval power and a global network of partners will both deter large conflicts and enable the United States to prevail in any engagement far from home territory.

The overwhelming might of the US Navy in World War II and after rendered the original Army Coast Artillery Corps increasingly obsolete. In conjunction, the ascent of strategic airpower and long-range bombing led to a shift to Army concentration on antiaircraft defense, until eventually US coastal defense units were dissolved in 1950. Coast artillery disappeared from the US arsenal because it was expensive, immobile, and irrelevant to the United States’ postwar doctrinal shift.

However, geopolitical realities have changed and, as evidenced by the capabilities of both our adversaries and allies, coast artillery has evolved without the United States.

Mobile Surface-to-Ship Missiles: Not Your Grandfather’s Coast Artillery

In essence, the United States determined the Army’s Coast Artillery Corps was obsolete for three reasons. First, it was believed that future US military operations would be waged far from US territory through the employment of friendly-nation staging bases coupled with unrivaled naval supremacy. Second, because any naval engagements were expected to take place far from US territory, coast artillery assets would be better employed as air defense assets. Third, Coast Artillery Corps assets were inherently expensive, were difficult and time consuming to emplace, and could not be rapidly moved (if at all), so replacing them with missile assets would better support the national strategic posture in the developing nuclear age.

However, the modern coast artillery capabilities of both our allies and adversaries are not clunky, colossal cannons rooted in fortresses on craggy cliffs as in The Guns of Navarone or the Nazi defense occupied French coasts. Just as air defense has transformed from machine-guns shooting at propeller planes to PAC-3 missile systems capable of downing supersonic jets and intercontinental ballistic missiles, modern coast artillery has evolved.

Mobile surface-to-ship missile (SSM) capabilities are an integral part of the militaries of both of the United States’ principal strategic competitors, Russia and China, and crucial to their antiaccess / area denial (A2/AD) strategies, particularly in the Pacific theater. The Russian armed forces field the Bal and the newer K-300P Bastion coastal defense missile systems. The Bal fires the Kh-35 antiship cruise missile with an estimated 260-kilometer range, while the Bastion fires the P-800 Onix missile with an estimated range of 300 kilometers.

Russia notably arrays these ground-launched antiship assets in the Kuril Island chain between the Sea of Okhotsk and the Pacific Ocean. Closely tying into its Arctic strategy, the Russian military deployed the Bastion to the illegally occupied Northern Territories of Japan in 2016 and to the Kuril Islands of Matua in 2021 and Paramushir in 2022

Unimpeded by the strictures of the Intermediate-Range Nuclear Forces Treaty, the SSM capabilities developed by China are highly advanced. China has an independent People’s Liberation Army Rocket Force, which has rapidly expanded in the past few decades and forms the backbone of China’s A2/AD strategy. Perhaps the most notorious of its SSM weapons are the DF-21D antiship ballistic missile (known as the “carrier-killer”) and the DF-26Guam-killer” antiship intermediate-range ballistic missile.

While theses adversarial capabilities are significant, fortunately the US Army also has a crucial ally it can rely on and learn from in the modern coast artillery realm: Japan.

Japan’s Surface-to-Ship Missile Regiments: Allied Collaboration in Waiting

Recognizing its archipelagic geography and position as the backbone of the First and Second Island Chains, Japan has fielded SSM units for decades. Its recent defense commitment to augment this capability presents an ideal opportunity for the US Army to collaborate with the Japan Ground Self-Defense Force (JGSDF) to develop integrated bilateral doctrine, planning, and exercises in a field it has long ignored.

The JGSDF currently fields five SSM regiments—three based in Hokkaido and one in Aomori prefecture in the north, and one in Kumamoto prefecture in the south. In recognition of increasingly aggressive Chinese naval activity, two new SSM regiments are to be stood up in Okinawa prefecture and Kyushu. In the past several years the JGSDF has also been proactively increasing basing of SSM batteries in the Nansei Islands near Taiwan, effectively forming overlapping concentric fields of fire covering maritime access from the East China Sea to the Pacific Ocean.

Although most regiments field the older Type 88 SSM, the future mainstay of Japanese missile capability is the Type 12 SSM. The Japanese Ministry of Defense is currently working to upgrade the Type 12 to extend its range from two hundred kilometers to nine hundred and beyond, as well as developing ship- and air-launched variants as part of its commitment to standoff missilecounterstrike capabilities.”

Furthermore, the JGSDF has committed to even further augmenting its long-range fires capability in the coming years, echoing the US Army’s own emphasis on long-range precision fires. In addition to its augmented Type 12 SSM capability, the JGSDF also intends to introduce  units fielding hypersonic missiles and hypersonic glide vehicles for remote island defense as well.

Japan’s well-established and burgeoning ground-based antiship capabilities provide ample reason and unparalleled opportunity for the Army to collaborate with the JGSDF in the field of coast artillery. The bilateral combination and coordination of long-range surface-to-ship munitions between the United States and Japan would present both a strong adversarial deterrent and a devastating lethal capability throughout the entire First and Second Island Chains.

The Coast Artillery Corps of Tomorrow

The US Army Coast Artillery Corps of tomorrow could combine operational reach and deployability as a light force capable of denying adversary use of key nautical terrain. The foundation for this capability has already been realized. The Army has already showcased its ability to conduct HIMARS rapid infiltration (HI-RAIN) missions, where M142 HIMARS (High Mobility Artillery Rocket System) platforms are delivered by C-17 aircraft, and then off-loaded, established in position, employed to engage targets, and extracted in under forty-five minutes. This capability, coupled with currently in-development ground-to-sea fires capabilities, should be viewed as the harbinger of artillery yet to come. Together with the right operating concept, these capabilities would enable the Army to close sea lanes, defend littoral sea lines of communication, and project force in the Pacific.

Modern coast artillery should not be conceptualized and developed simply as a static defensive capability within US territorial confines, but as a forward projection construct that would enable the United States to safeguard and cooperate with partner nations while also, in the event of large-scale combat operations, serve as a forward deployable A2/AD capability.

The employment of land-based antiship missiles from expendable launch platforms that may be deployed to land masses throughout the world with minimal logistical forethought would provide the United States the ability to both secure its own lines of communication, and to potentially close or harry those of adversaries. That is, the logistics needed to train, equip, and deploy light antiship platforms is substantially less than that which is needed to deploy naval assets to cover the same areas.

This is a critical capability gap: China has been extending its Pacific view of hegemony like a game of Go. With each calculated step, it brings more land, populations, and military lines of communication under its influence. However, cheap, expendable, and rapidly deployable land-based antiship missile platforms would allow the United States to conceptually deter adversarial progress by projecting this capability. While deployability is the essential piece to this vision of a robust future coastal artillery capability, employing relatively cheap and ultimately expendable coastal artillery packages means that the United States may threaten strategic-level adversarial assets (ships) with tactical-level systems (M142 HIMARS platforms). In this, commanders would have the ability to better take calculated risks when employing antiship assets; it is more palatable to risk a $5 million HIMARS platform to deny a littoral battlespace that it is to risk one destroyer that cost upward of $3 billion.

A Coast Artillery Corps element deployed to a small island, be that in the Nansei Islands near Taiwan or the Aleutian Islands between the Arctic and Pacific Oceans, can effectively turn that position into an unsinkable operational asset capable of challenging adversarial strategic assets.

This rediscovered relevance, in combination with the ability to employ relatively low-cost and rapidly deployable land-based antiship missiles, should challenge the current unconscious Army prejudice against the concept of coast artillery and the development of a coherent and cohesive corps to reanimate this long-neglected crucial aspect of future warfare thoughtfully and systematically.

The Army Can’t Miss the Boat

In warfare, land and sea have always been inextricably tied together. This is a lesson the Army has forgotten. In a theater such as the Pacific it is neither the sea nor the ground alone that is important—it is the interrelationship of the two that is crucial. It is mastery of the interplay of land and sea that will prove imperative in the future, as it did in the forgotten past.

Surface-to-ship fires is an essential, and currently poorly developed, element of the MDO construct. MDO cannot be fully realized by a land force that cannot secure its local ingress and egress points for its sea lines of communication.

The employment of fires against moving naval targets requires significant technical proficiency coupled with leadership that understands the maritime implications of target engagement and resulting battle damage assessments. In short, the Army needs a corps capable of accurately employing ground-to-sea fires in support of operational goals in a manner that does not jeopardize strategic priorities.

This would require more than just new weapons and equipment, but also changes to organizational culture, training, and more. As the Army continues to prepare for large-scale combat operations and shed its infantry brigade–focused counterinsurgency culture, it will naturally search for its role in the largely maritime Indo-Pacific region. A central component should be long-range standoff missile capabilities that can target and engage surface, air, and maritime assets from concealed locations.

Re-creating the Coast Artillery Corps—with coherent and developed doctrine, tactics, training, manning, and ethos—seamlessly capable of combined and joint integration, is a necessary organizational step for the future Army. The service must widen its aperture beyond the idea of facing only an enemy ground force in land warfare. It needs to school itself on enemy maritime capabilities, tactics, and strategy. With this goal in mind, it should expand its officer education to include instruction on coastal geography, pathways, chokepoints, and the law of the sea, to name but a few fields.

Failure to recognize the potential promised by embracing the role of destroying ships from shore and forging a modern Coast Artillery Corps risks squandering an unparalleled opportunity for the Army to be a pillar of modern joint defense strategy and undermining its future Pacific relevance. In short, overlooking the military significance and immense potential of modern surface-to-ship fires will ultimately result in the Army missing the boat.

Major Alec Rice is an active duty US Army JAG Corps attorney currently assigned to the National Security Law Division, Office of the Judge Advocate General. He is a former chief of national security law for US Forces Japan and a graduate of the 66th Japan Ground Self-Defense Force Command and General Staff Course.

Major Elliot Pernula is an active duty US Army JAG Corps attorney currently serving as the chief of administrative law for the 3rd Infantry Division. He formerly served as the brigade judge advocate for the 75th Field Artillery Brigade and is a 2022 graduate of the US Army’s Command General Staff Officer’s Course.

The views expressed are those of the authors and do not reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.

Image credit: Sgt. Melanye Martinez, US Marine Corps