If NATO is required to respond to Russian aggression against its Baltic members, U.S. naval forces could provide flexibility and help support and contain the fight.
In light of Russia’s aggression in Eastern Europe, it is essential that the United States consider the operational challenges it would face in defending the Baltic NATO member states. Russia could present NATO with an ambiguous attack or even a fait accompli, much as it did in Georgia and Ukraine. Absent clear and unambiguous warning, it is unlikely the alliance could provide a successful defense to Lithuania, Latvia, and Estonia.1 Such a failure not only would put the Baltic at risk but also would threaten the legitimacy of NATO itself, because if NATO fails to protect its Baltic members, this would delegitimize Article 5 and the entire raison d’etre of the alliance.2
To reinforce the Baltic states and roll back Russian aggression, the United States and NATO would have to surge forces quickly over considerable distance. In short, Russia enjoys a time, distance, and decision-making advantage, which creates a strong first-mover advantage in a Baltic scenario. There is a role for U.S. naval deterrence, and four naval defense scenarios demonstrate ways U.S. sea power can mitigate these challenges.3
Baltic Deterrence Scenario
Deterring aggression is a fundamental mission of the U.S. Navy and is of increasing importance with the reemergence of great power competition.4 There are two strategic modes of deterrence:
• Deterrence by punishment, which presents the adversary with the prospect of prohibitive costs
• Deterrence by denial, which aims to affect the adversary’s decision-making calculus by lowering the probability he will achieve his objective5
U.S. sea power can play a role in deterring crises indirectly by conveying the credible intent to punish versus deny. Given the imbalance in local forces, U.S. sea power is unlikely to convince Russia not to initiate an attack in the Baltics; thus it contributes little to deterrence by denial. Nor can it prevent Russian land forces from accomplishing their operational objectives. The utility of U.S. naval forces before such a conflict is to act as tripwires and, by their presence, demonstrate enough of a U.S. stake in Baltic defense to proscribe a Russian attack.
By putting U.S. service members at risk, we demonstrate our commitment to the Baltic states. This greatly complicates the Russian calculus regarding a potential conflict because it now risks war with the United States. Such a tripwire force contributes to the credibility of the U.S. deterrence commitment.
Baltic Defense Scenarios
Based on observation of recent Russian military doctrine and activities, as well as open-source analyses of Russian strategies, four possible scenarios necessitating defense of the Baltics present themselves:
• The fait accompli: In this scenario, Russia invades one or more of the Baltic states, rapidly seizing territory and presenting NATO with a fait accompli. While NATO may invoke Article 5, the alliance lacks good options for recapturing the territory of allies short of a protracted conflict.
• The high-end fight: In this scenario, rather than capture the Baltics, Russia cuts them off from reinforcements. Russian units in Kaliningrad and Belarus deny access through the Suwalki Gap between Poland and Lithuania, while elements of Russia’s Sixth Army threaten Baltic states from the east.
• The jab and grab: Based on the Georgia and Ukraine crises, this scenario involves a minor Russian incursion—not in a city, but in a less significant piece of terrain—to challenge NATO’s credibility and test its response.
• The gray-zone leverage: In this scenario, Russia leverages sympathetic compatriot communities in vulnerable Baltic states to agitate for secession or to set up the annexation of a city or territory with a large ethnic Russian population.6
The role of U.S. sea power is examined in each scenario.
Sea Power for the Fait Accompli
U.S. sea power initially will have few available assets in the Baltic, and the Navy may not be deployed into the Baltic Sea—especially in the early stages of conflict, before Russia’s antiaccess/area denial capability has been degraded—since this scenario assumes a large-scale Russian gamble to occupy the Baltic. Given the steep costs Russian air and coastal defenses present for the United States in the Baltic, requiring time for buildup of assets and enablers, national leadership could choose to look elsewhere first for both kinetic and nonkinetic responses.
However, once Article 5 is invoked, the battlespace could expand to the North Atlantic and Mediterranean. If that happens, a potential task for the U.S. Navy could be to attack Russia’s naval assets in the Mediterranean and its military presence in Syria. This would remove Russian elements from the Mediterranean and secure NATO’s southern flank.
U.S. sea power would deploy first to secure the Atlantic sea lines of communication (SLOCs) and join allies to interdict Russia’s Northern Fleet in the Norwegian Sea should it be deployed. U.S. forces would engage in antisubmarine warfare (ASW) in the Greenland-Iceland-United Kingdom-Norway Gap and in the Eastern Mediterranean. This would involve offensive mining of choke points to bottle up Russian naval forces.
NATO allies would have to decide whether to enter the Baltic in force or to effect sea denial at a much lower cost. Partners such as Sweden and Finland typically plan for sea denial strategies. Indeed, all the states in the region are likely to have a sea denial strategy rather than a focus on sea control. Given the above, U.S. Navy tasks in theater initially will focus on securing the Atlantic SLOCs; providing joint fires; containing Russian surface and submarine forces in their northern bases on the Kola Peninsula; dispatching and covering U.S. Marine Corps reinforcements to northern Norway; and providing sea lift for the Army into Europe.7
Depending on NATO’s strategy, it also is possible the U.S. Navy’s ballistic missile defense (BMD)-capable Aegis destroyers would be more useful for long-range air and missile defense than for their offensive capabilities. Even if NATO chose to wait for force generation prior to initiating conflict, these Aegis-BMD platforms likely would have more utility in the antiballistic missile mission than in the joint fires mission. Similarly, submarines with special modules could be charged with entering the Baltic to insert naval special forces—SEALs—for targeting and reconnaissance behind enemy lines.
Should NATO lose the initial fight for the Baltic, sea power will be vital. Sea control ensures U.S. (and Canadian) reinforcements can flow—the most critical factor to ensuring alliance cohesion—enabling a collective and sustained war effort and the potential for inflicting heavy losses on the adversary. Keeping forces in contact in the North and Norwegian seas could help counter a Russian perception that the conflict is over simply because they have achieved their objectives. Therefore, the demonstration of sea control is a way to change the Russian strategic cost-benefit calculus. Furthermore, it supports European political will as it demonstrates U.S. resolve while forces are being generated in or lifted into the European theater.
Sea Power for the High-End Fight
In this situation, the Navy will carry out the same missions as in the fait accompli scenario, but the battle likely will result in steady attrition of NATO air power and Russian air defenses. The U.S. Navy may be called on to enable “forced entry” into the Baltic to support operations against Kaliningrad or even St. Petersburg. Policy failure frequently leads political establishments to engage in escalation, and the United States may use its Navy to expand the fight horizontally against Russia. As a consequence, the Navy might find itself engaging Russian forces elsewhere besides the Baltic and northern European theater.
If so, U.S. Navy capacity could become an issue. Between fulfilling the ASW mission, escorting carrier groups, and providing joint fires and local air defense, the Navy may not have enough forces for everything. ASW is a must for both homeland defense and protecting SLOCs. In other words, the United States will have to make a choice between fighting locally and fighting globally.
Horizontal escalation is not the complete solution for the United States in the high-end fight, but it is an attractive option. Initially, the U.S. Navy could be tasked with denying the Russian Navy the ability to sortie from its homeports, but if the fight in the Baltic goes poorly, it is possible the United States will look to capture Russian territory—such as the Kuril Islands—to trade. Russia no doubt expects a U.S. counterattack in sparsely defended regions and is modernizing defenses to make horizontal escalation more costly. Still, defending Russia’s vast periphery is an aspirational goal at best given the limited resources at its General Staff’s disposal. The United States has capable allies and partners in the Pacific, Mediterranean, and Black Sea. If they are convinced they must support offensive operations, Russia would be overmatched in these theaters by U.S. sea power combined with regional allies.
Russia cannot sustain a protracted conventional fight in the Baltics; it eventually will begin to incur significant losses, especially once its air defenses are neutralized. In response, Moscow may look to kill a high-value target—e.g., an aircraft carrier or large-deck amphibious warship—in a bid to force a conversation on war termination. Similarly, if faced with defeat in Kaliningrad, Russia might escalate to nuclear first use against a U.S. Navy ship.
Unlike the United States, which has all but enshrined as dogma a no-first-use nuclear doctrine, Russia has never rejected the possibility. Still, the prospect of nuclear escalation over the Baltic should be viewed as a last resort. Russian doctrine indicates a willingness to use nuclear weapons in local or regional conflicts, but this is largely a deterrent posture to prevent the West from intervening in Russia’s near abroad, i.e., the countries adjacent to its borders. The more likely possibility is that Russia uses nuclear weapons to support a war termination strategy if its forces appear likely to be defeated.
Russian “red lines” for nuclear first use thus remain unclear. They could include loss of any sovereign territory, to include Kaliningrad and the Kuril Islands, or just Russia proper. While it is difficult to imagine Russian use of nuclear weapons as a first resort, it is likely Moscow would deliberate nuclear options if faced with conventional defeat or perceived existential threat.
This is a story of potentially catastrophic success: as NATO approaches conventional victory, it also nears the prospect of nuclear escalation. In a nonstrategic nuclear attack, a U.S. carrier or destroyer could be a lucrative target for tactical nuclear weapons at sea. Moscow may well see BMD-capable destroyers as “strategic” or may choose to use nuclear weapons to attack symbolic or key enabling assets. The objective would be to force conflict termination on Russian terms, without inflicting monumental civilian casualties and long-term catastrophic environmental damage.
By crossing the nuclear red line, Russia could split Europe from the United States and force a “gut check” of the political will to continue combat operations. The United States would have to consider whether to retaliate with nuclear weapons, to escalate, to ignore the strike and proceed with combat operations, or to conduct a similar strike elsewhere. The prospect of a nuclear exchange confined to Europe also could divide NATO. This scenario is well within the realm of possibility, given that Russia maintains a diversified force of nonstrategic nuclear weapons.
Sea Power for the Jab and Grab
In this scenario, NATO will face a difficult choice. The alliance could either invoke Article 5, but with no prospect of successfully prosecuting a conflict at the outset, or accept “salami slicing,” ultimately rendering collective security guarantees—which are at the heart of the defensive alliance—meaningless.
The United States has two courses of action: do nothing or do something, such as engage in warfighting to retaliate immediately or punish Russian behavior by other means short of direct military confrontation, including retaliatory cyber attacks. NATO could lose more by declaring Article 5 than by punishing Russia through non-military/nonkinetic means with the hope they would prove coercive.
The jab and grab illustrates Russian advantages in the fight. Russia can achieve limited objectives vis-a-vis NATO without having to take much territory or necessarily be the initiator of a conventional battle. For these reasons, this scenario might be the most likely one Russia would chose to destabilize NATO.
Sea Power for the Gray-Zone Leverage
In this scenario, Russia leverages sympathetic compatriot communities in the Baltic states to agitate for secession or to set up the annexation of a city or territory with a large ethnic Russian population. This population then would receive military support from Russia short of conventional or traditional warfare, although conventional weapons—armor, artillery, or surface-to-air missiles—could be employed. Alternately, Russia acts through surrogates, militias, or unmarked special operations forces to maintain a veneer of distance from an ongoing conflict, leaving the nature of the hostility ambiguous enough to confound a conventional response. This allows Russia to obtain some of its goals without a formal declaration of war, putting the burden of such a declaration on NATO.
While the United States surely would be aware of unrest in the Baltic states, it would be unlikely to divert high-value assets, such as a carrier strike group, to the region in response to what seems to be domestic unrest. Even so, a strike group might be considered overkill. In terms of showing support and commitment versus putting key assets at risk, the United States is likely to err on the side of caution. Practical considerations also will get in the way, as U.S. naval assets are unlikely to be on-scene and ready to respond in a rapidly developing irregular contingency. Russia owns the advantage here, shaping the battlespace and establishing a pretext for unrest while keeping the U.S. Navy at arm’s distance. This greatly frustrates U.S. response options.
Should an aggrieved state choose to respond—and should NATO choose to accept Russian parameters for the conflict—the conflict would remain framed as a Baltic state against unconventional forces. Responding NATO forces could choose to act in a similarly unconventional fashion or employ conventional forces with just enough strength to defeat the irregular actors. In either case, the objective is to avoid drawing the sponsor state (Russia) openly and conventionally into the fight.
In this gray-zone space, the role of the U.S. Navy is predominantly clandestine, relying on special operations forces. Navy SEALs and special warfare combatant-craft crewmen can be inserted quickly and covertly to conduct direct action, foreign internal defense, or security force assistance operations in an irregular (or light conventional) Baltic contingency. They can help Baltic countries repel the adversary’s irregular forces. The intention is to maintain the political fiction of substate conflict, responding with enough force to place the onus on the aggressor to decide whether to escalate. Doing so allows NATO to maintain credibility without invoking Article 5 and jeopardizing a conventional crisis—assuming the aggressor opts to deescalate. Should a Baltic state call for Article 5 consultations, it would present a new set of options for the United States and NATO. A NATO invocation of Article 5 involves a public recognition of the aggression, thus piercing the veil of ambiguity.
We should not think of sea power in a vacuum, but instead examine the Navy’s critical role in a battle to defend the Baltic states as part of a joint and combined fight. If maintaining a land access to relieve and defend the Baltics is not viable (which most likely it would not be), sea power is one of the few alternate, albeit risky, options for having U.S. forces support the conflict. Sea power could help keep the battle geographically contained, but it also could provide the option for horizontal escalation, which the joint force would otherwise be without. Often Baltic scenarios ignore the fact that all the states involved are littoral to the Baltic Sea, and—while Russia would prefer the contest to be entirely a land battle, where it holds distinct advantage—NATO’s earliest response is likely to come from the air and sea. In other words, by using sea power we negate the Russian advantages and play more to our strengths.
Ultimately, Russia has great asymmetric advantages in terms of its ability to bring forces to bear against the Baltic states. In that context, U.S. sea power could provide flexibility and contribute to prosecuting a conflict against Russian aggression in several ways.
• Horizontal escalation: The U.S. Navy’s most valuable contribution to deterring Russia is in its ability to escalate conflict regionally and globally. While local geography and Russia’s military capabilities present a challenge to the U.S. Navy’s ability to fight in the Baltic Sea, it is possible to hold at risk Russian forces in the Eastern Mediterranean, Black Sea, Norwegian Sea, and even the Pacific to greater effect.
• Tripwire forces: The U.S. Navy could rotate forward-deployed patrol craft or littoral combat ships to the Baltic Sea to serve as tripwires and demonstrate our commitment to the Baltic states. While there are considerable drawbacks to this approach, it could be used to increase Russia’s risk of punishment for aggression against the Baltic allies.
• Gray-zone capabilities: The Navy’s vast experience in irregular warfare and maritime security could be used to great effect in a scenario where Russian aggression is ambiguous.
• Demonstrated capability: The intent to use any of the U.S. Navy’s capabilities—especially power projection, sea control, and all-domain access—to support a deterrence strategy must be clearly communicated to Russia. The challenge remains in making the threat of punishment credible. While much of this responsibility to forge a comprehensive strategy resides at the level of national policy, U.S. Navy leadership has a role and can be active in demonstrating U.S. Navy capabilities through visible exercises and operations.
The greatest advantages of U.S. sea power are its global posture, scalability, sustainability, lethality, flexibility, and maneuverability, all of which can greatly contribute to countering Russian aggression. The Navy’s capacity to surge, as well as to sustain meaningful presence at a distance, allows the force to modulate a response where and when it choses. Furthermore, its precision-strike capabilities can hold at risk Russian assets locally, regionally, and globally. Whether NATO is required to respond to Russian aggression in the context of Article 5 or in some other capacity, U.S. sea power can play a prominent role.
Author’s note: The author acknowledges the significant assistance of Alexander Alden, Michael Kofman, Alarik Fritz, Joshua Tallis, and Scott Truver from the Center of Naval Analyses in the development of this essay.
2. Article 5, The North Atlantic Treaty; Washington DC; 4 April 1949. The principle of collective defense is at the heart of NATO’s founding treaty. It remains a unique and enduring principle that commits members to protect each other and sets a spirit of solidarity within the alliance. Article V states, in part: “The Parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all and consequently they agree that, if such an armed attack occurs, each of them, in exercise of the right of individual or collective self-defence recognised by Article 51 of the Charter of the United Nations, will assist the Party or Parties so attacked by taking forthwith, individually and in concert with the other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area.” The critical point of Article 5 is not the speed by which the NATO’s North Atlantic Council can declare it, but the fact that there is no automaticity associated with it.
3. Although defending the Baltic NATO would be an “all-hands” effort, with all branches of the various armed forces combined into a unified force, this essay looks only at the contribution of the U.S. Navy. It is not intended to downplay the importance of the joint planning process or the centrality of NATO or the United States in enacting a strategy of mutual defense. On the contrary, by focusing exclusively on the U.S. Navy role, Navy warfighters should be encouraged to think about how to more effectively use the U.S. Navy to support the larger effort.
4. Chief of Naval Operations ADM John Richardson, USN, “A Design for Maintaining Maritime Supremacy,” November 2015.
5. Glenn H. Snyder, Deterrence and Defense: Toward a Theory of National Security (Princeton: Princeton University Press, 1961, 14-16.
6. See John Chambers, “Countering Gray-Zone Hybrid Threats: An Analysis of Russia’s ‘New Generation Warfare’ and Implications for the US Army,” Modern War Institute, USMA, 18 October 2016. “The gray zone is an operating environment in which aggressors use ambiguity and leverage non-attribution to achieve strategic objectives while limiting counter-actions by other nation states. Inside the gray zone, aggressors use hybrid tactics to achieve their strategic objectives. While hybrid threats have historically been associated with irregular and conventional warfare, their use in the gray zone leads to a dichotomy between two types of hybrid threats that can mainly be attributed to the need for ambiguity and non-attribution in the gray zone.”
7. The military realities of significant Russian military and naval power adjacent to Norway could neutralize our ability to use Norwegian bases to contain Russian forces, thereby allowing the Russian Northern Fleet easier access to attack NATO shipping crossing the North Atlantic.