“The supreme art of war is to subdue the enemy without fighting”
~ Sun Tzu
Why didn’t Russia deploy amphibious forces to the shores of Odesa in the spring of 2022? At that point, Russians confronted the failure of the drive to Kyiv and challenges along a long front. A potential landing might have turned a flank or presented hard choices to Ukrainian leaders. Unarmed with first-hand evidence of Russian decision-making but well-served by hindsight, the authors assess that the amphibious flanking attack didn’t happen because it was infeasible. Ukrainian maritime defenses were unexpectedly effective. Sustaining forces ashore would be precarious. Isolated Russian troops ashore would be more liability than asset, and so the expected payoff from any landing was low. Russian commanders faced an acute area denial challenge. Amphibious warfare strategy, it seems, is in need of some exploration because, after a deterrence failure in February 2022, Ukraine used tools of sea denial to deter the Black Sea Fleet from an amphibious landing in March.
This snapshot raises a question and points to an answer. What can you do with amphibious forces given current area denial, especially sea denial, measures; particularly in Europe? Those tools of sea denial mean that fouling the waters is easy but clearing them is hard. Because of this, sea denial is easier today and sea control is growing more challenging. Threats to large landing ships make traditional amphibious assaults—called forcible entry operations in the American vernacular—riskier. Simply using amphibious forces to do ground operations in a new patch of land is too hazardous. On the other hand, a divergent model has promise to contribute to sea control.
Concepts designed for the Indo-Pacific have value in Europe
Specifically, deploying multiple, distributed, mobile cohorts of NATO marines ashore will support a broader effort. To gain and maintain sea control will be long, resource intensive, and entail a complex mix of complementary measures. In Europe, NATO can marshal potent amphibious tools, but will need new employment models to use them effectively. The traditional model expects a methodical sequence of actions to set conditions for landing. A new “outside-in” model uses small landing forces preemptively to establish sea and archipelagic denial. This is most valuable for deterrence, but counts also as insurance in case that deterrence fails.
Four factors have the most impact on how allied amphibious forces can operate in today’s operational environment:
- First is the spread and variety of threats to maritime transit. Ukraine’s successful strikes on Russia’s Black Sea Fleet and the Houthis’ parried attempts to disrupt Red Sea commerce illustrate the same point. The latent potential to strike ships at sea is widespread. Beneath the surface and out of view, sea mines, torpedoes, and other nefarious but subtle instruments of destruction or disruption abound.
- Second, an accident of geography places many key geopolitical flashpoints of today along narrow waterways. Any list of potential triggers for major armed conflict between defenders of the current order and its challengers includes territory adjacent to narrow or enclosed waterways such as the Mediterranean, Black, or Baltic Seas. Regardless of where an adversary might strike, be it in Lithuania, Taiwan, or the contested territories of the South China Sea, maintaining sea control will be critical to defense. Consider that Finland relies on maritime transit for 90% of its imports and exports.
- Third, NATO’s two newest members, Finland and Sweden, have mature and hardened capabilities to frustrate aggressive maritime harassment and targeting. Integrating such skills is a key advantage of their accession.
- Fourth, sophisticated defenses against aircraft and missiles are possible but costly. What we’ve seen in the past year in the skies over Kyiv, Tel Aviv, and the Red Sea is that air and missile defense is feasible but not simple. Also, past inhibitions are eroding. When it comes to defense, the adage remains true that you defend nowhere when you defend everywhere. However, a federated network of formations that are capable of sensing and shooting—or sharing critical information in a timely manner—can increase defensive depth and the likelihood of successful defense.
Sea control
Sea control has always been a high bar. Worse, the height can change with little warning. The diffusion of technology and waning inhibitions on use produce the current variability. An economist observing military planners might fault them for treating sea control—a continuous variable—as if it were binary. Such planners fail to see the shifting height of the bar and so underestimate the difficulties in clearing it. Sea control is hard precisely because sea denial is not. The threats are many. Munitions such as missiles and mines can be fired at depth from conventional or irregular forces. Vessels piloted improperly can themselves block maritime chokepoints. This can happen inadvertently, as seems true in Baltimore harbor recently or as in the Suez Canal blockage of 2021. Or perhaps even a press release regarding intent to deploy mines or strike targets might be sufficient to foul a key passageway. Despite the threats, the imperative to sustain maritime transit is critical to American interests and those of its friends and partners.
An Operational Approach: Use landing forces from the outside-in
Countermeasures must be complementary and coordinated. In the twentieth century, the most serious threat to maritime transit was the submarine. Through trial and error, twice during World War I and World War II, the U.S. Navy and partners relied on a concentration of maritime forces, convoys, to protect shipping. Today, a different concentration of defensive and offensive measures may be required to ensure transit at chokepoints and narrow seas. Defense against aircraft, missiles, mines, sabotage, and undersea attack will require a blend of capabilities that will be complex and intensive. In an active conflict, such multi-domain combined arms cooperative efforts will be possible only in specified places and times. Like a convoy, these teams will assemble and separate. When an adversary is determined to contest it, sea control will be episodic. Sea control may be a continuous variable, but it’s also likely to be continuously varying.
Amphibious forces ashore will be critical enablers within that contemporary integrated convoy system. Dispersing mobile, connected cohorts of allied marines on islands and coastlines inside the contested zones but within friendly territory will provide important advantages. Positioning these forces on site in advance of conflict while retaining the ability to re-deploy before conflict is likely to have an even greater impact in that they could also create a deterrent effect.
An “outside-in” distribution model would place amphibious ships outside the range of the most potent threats while NATO marines operate a network of small outposts supported by rudimentary and mobile staging bases within friendly territory. The “outside-in” model treats landing ships more like other aircraft carriers. They should remain offshore within a combined-arms protective anti-access, area-denial bubble of their own. From those landing ships, allied landing forces would go out and return, just as carrier-based aircraft do. Unlike such aircraft, landing forces would have longer time on station. Dry land provides that benefit to intermediate and advanced outposts. The outposts would be mobile and recoverable, with tasks to secure key terrain, sense adversary activities, shoot or sustain when directed, and share information with the allies in that area. The task to share—materiel, expertise, communications, some limited hardship, and most especially intelligence—has proven to be a potent resource the United States can offer to its friends in Ukraine. With the accession of Sweden and Finland to NATO, building robust and rapid information sharing across the Baltic Sea region at the tactical level will be critical to deterrence and to warfighting should deterrence fail.
Can such outposts continue to function in an active conflict? Will the rationale that led Russian leaders to defer landing in Odesa apply here? The cases are not symmetrical. Protection of allied maritime transit will be defensive and rely on a logic of conventional deterrence by denial. If deterrence fails, the network of outposts would be vulnerable but also formidable. One promising approach to limit vulnerability will be to coordinate activities in time across the full range of diverse capabilities. At designated locations and within constrained windows of time, say for example for five hours every day and a half, allied forces might concentrate active defensive measures to “green light” allied sea control. This may include an overwhelming combination of missile strikes, electronic attack, unit repositioning, long range strikes, merchant ship movement, spoofing, and other activities. Because such activities rely on overmatch and coordination with civil authorities, these periods of concentrated active defense “convoy cycles” could be declared in advance. Military planners are accustomed to organizing activities in sequence according to phases. Given the threats to maritime movement and air traffic, it may be wiser to plan for cycles of concentrated active defense.
Maritime movement in an acute active conflict might represent some version of the children’s game “Red Light, Green Light.” When the light is red, the players remain still and inconspicuous. When the light is green, all players rush to make progress. One key difference applies to this version of the game. Here, the players themselves make the lights turn green, but only for a while.
Counter-arguments
This vision, projecting NATO marines onto coastal and island territory of friends menaced by an aggressor, raises some doubts. Some skeptics believe that it invites defeat in detail. In 1962, Indian leaders thought that penny packets of armed outposts would deter Chinese incursion along a disputed border. The People’s Liberation Army overran the outposts serially and easily. The difference here is that the proposed landing force bases will be off-center from the principal adversary objectives, they will be connected, and they will be maneuverable. Furthermore, as the defense of Kyiv at the Hostomel airfield shows, small units can be effective at counter landing operations. The skeptics are right that the forward units will be under serious threat in a shooting conflict. They underestimate the benefits offered.
A second objection might be that NATO marines are too versatile, ready, and valuable for this mundane work. Marines from many European allied nations represent the most well-trained and ready forces. Critics would say that to commit such agile units to fixed site security—when other forces could do the same job just as well—is a mistake. Nonetheless, using capable forces for such work has value in signaling and sharing. The commitment of these forces will be a credible indication of resolve in a crisis. Further, the tactical sharing between local friendly units and the landing forces will be constructive if the crisis turns to active conflict. Stand-in forces, employed early and placed in strategically relevant positions, demonstrate commitment to deterrence and capability to defend if conflict is unavoidable.
Employment of distributed, disaggregated forces within range of the enemy is risky. Massed amphibious formations near to shore can be struck. Distributing smaller formations across the theater complicates adversary calculations and spreads their capabilities, capacity, and attention. Disaggregation–separating amphibious forces from their ship–risks the freedom of maneuver typically attributed to amphibious formations. Sustaining these forces ashore will also be a significant challenge. However, disaggregating within the confines of Allied nations enables multiple options to re-constitute; access to national transportation capabilities including road, rail, small boat, and air support maneuverability and re-deployment. The situation in the Baltic Sea region has improved on this score. Finland and Sweden joining the Alliance enables friendly forces to move more freely than ever before. Turning on the “green light” reduces these risks.
Are allied marines best suited to the role of reserve?
If you commit such forces to advanced base activities, it is worth exploring whether or not you have expended your reserve.
Three considerations apply:
- The advanced forces must be recoverable. This may be challenging or time consuming but should be feasible with organic lift and a hefty treatment of “green light” applied to adversary disruption capabilities.
- The landing forces in question are relatively small. The most robust is the U.S. Marine Expeditionary Unit. This is particularly versatile and capable, but its ground force contingent is battalion sized. That is a meagre reserve in a theater-wide conflict.
- Given the high stakes and nuclear considerations of any crisis between the North Atlantic Alliance and Russia, withholding a conventional reserve force from deterrence activities seems unwisely stingy.
A Scenario
Imagine a future crisis in Europe involving a major regional power and a NATO member.
The aggressor declares an intention to annex territory of this ally and positions military forces accordingly. Allied forces bolster defense in the territory in question, and also activate a defense in depth. One facet of that defense in depth is the positioning of mobile landing force bases to secure maritime key terrain and observe adversary capabilities. These mobile, dis-aggregated, forward deployed forces coordinate across all domains to create temporary conditions of sea control through which the Allies reduce the aggressor’s ability to foul the waters. This likely comes in the form of a large-scale operation that will certainly take intense planning, coordination, and communication. But that combination of allied power projection, front-line defense tied to an extended defense in depth presents the aggressor with an Odesa option.
In this case, deterrence operates from positioning and partnership. The aggressor confronts an infeasible operation likely to fail.
Author note: The views expressed represent the personal opinion of the authors and do not reflect the U.S. government, the U.S. Marine Corps, the Naval Striking and Support Forces NATO, or any other entity.
Feature image credit: MOD
Nathan Storm
Nathan Storm is a U.S. Marine helicopter pilot who graduated with honors from the NATO Defense College. He deployed twice from the east coast as part of Marine Expeditionary Units, twice as part of the Marine Corps’s stand in force in the Indo-Pacific and currently serves in Europe alongside Allies at Naval Striking and Support Forces NATO.
Barret Bradstreet
Barret Bradstreet is an infantry officer in the U.S. Marines assigned to Naval Striking and Support Forces NATO. He served overseas in the Indo-Pacific, the Middle East, and Europe.
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Barret Bradstreet#molongui-disabled-link
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Barret Bradstreet#molongui-disabled-link
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Barret Bradstreet#molongui-disabled-link
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Barret Bradstreet#molongui-disabled-link
