Commentary by Mark F. Cancian Sean Monaghan and Daniel Fata

NATO will hold a leaders’ summit in Vilnius, Lithuania, next month. In preparation for that summit, the CSIS International Security Program conducted a study on Baltic security. This commentary summarizes the results of that study. CSIS will publish the full report on July 6.

Russia’s invasion of Ukraine has radically changed NATO’s security environment. The renewed sense of threat is perhaps most acute among the three Baltic members―Lithuania, Latvia, and Estonia―which have long been vulnerable to Russian aggression.

Ahead of the NATO leaders’ summit in Vilnius, Lithuania, next month, the CSIS International Security Program assessed defense and deterrence in the Baltic region. The study considered Russian threats, NATO responses, the requirements of effective deterrence, and progress toward the goals set at last year’s historic 2022 summit in Madrid. It concluded that the Baltic states are in a particularly dangerous situation and, despite having taken extraordinary measures for their security, need help from the entire NATO alliance.

Decisions made in Madrid and NATO’s new strategic concept have set the alliance on the right course for dealing with the new environment. However, implementation of the Madrid commitments has been uneven. NATO leaders will need to ensure the decisions taken in Madrid to reassure allies and strengthen deterrence are on a clear path to implementation.

Europe’s Changing Security Environment

Russia’s war of aggression in Ukraine has transformed the European security environment by dramatically reviving the possibility of cross-border invasion. The Baltic countries are at the forefront of this security shift. The summit host nation of Lithuania faces particular challenges given its location between the Russian enclave of Kaliningrad and Russia-aligned Belarus and the need to keep the Suwałki Gap open―a 40-mile (65 km) corridor linking Poland to Lithuania and the other Baltic states.

NATO and Europe have responded strongly and with remarkable unity to the Russian aggression by providing massive aid to Ukraine, increasing defense budgets, deploying forces to Eastern Europe, and imposing unprecedented sanctions.

The United States has shown a solid commitment to NATO and European security by providing over $75 billion of assistance to Ukraine and deploying over 20,000 additional troops to Europe. However, the United States must balance its efforts in Europe with countering a rising and belligerent China in the Indo-Pacific―what its National Defense Strategy calls the “pacing challenge.” As a result, Europe will need to step up to strengthen deterrence in the Baltic region.

Americans need to keep in mind the stakes involved. The Baltic states vividly remember that, under Soviet rule, free elections ended, national culture was Russified, forced collectivization of agriculture impoverished farmers, religion was suppressed, and over 100,000 citizens were deported to Siberia.

Threats to Baltic Security

If the Russian invasion of Ukraine were not enough, Putin’s veiled threat to the Estonian city of Narva last year shows that the primary threat to the Baltic states comes from Russia. Despite the hopes of the West and many of Russia’s people, postwar Russia is unlikely to become a liberal democracy at peace with its neighbors. Instead, Russia will likely be authoritarian, revanchist, suspicious of the West, and a major military power.

Although Russia’s military has lost heavily during the war in Ukraine, it will rebuild when the war ends. Indeed, Russia has already mobilized its citizens and is taking near-term steps to expand its forces permanently. Estimates vary widely on how long it will take to reconstitute fully, but that reconstitution will happen sooner or later. Russia already has more active military forces now than it did before the war.

One result of the Russian attack on Ukraine is that the world can now see how Russia plans and conducts military operations. Future attacks will likely have five elements: shock and awe, decapitation of national leadership, missile strikes against fixed military targets, deep heliborne insertions, and deep attacks by armored columns. A Russian attack will be swift, violent, and aimed at rapid and complete victory. There will be little time for defending troops to prepare and get into position.

In looking to the future, NATO should hope for the best but prepare for the worst. During the Cold War, NATO adopted the maxim that it should prepare for the Soviet Union’s “maximum intentions and capabilities.” Prudence, combined with an unpredictable and dangerous Kremlin, requires NATO’s leaders and military planners to make the same assumption today. As an Estonian general put it recently: “The times aren’t going to be easier for us in the near future. . . . Russia’s threat is not getting smaller.”

The Military Status of the Baltic States

The Baltic states are taking strong measures to defend themselves. All three Baltic states have increased their military budgets substantially as the threat from Russia has increased. For example, Lithuania’s military budget has tripled since 2008. As a percentage of GDP, all three Baltic countries exceed NATO’s 2 percent goal for military spending, a level only seven other NATO members have achieved. Now all three have agreed to go further and spend 3 percent of GDP on defense.

All the Baltic countries have reinstituted conscription, which only four other NATO countries currently have in place. As a percentage of the population in uniform, the Baltic countries are far ahead of most of the rest of NATO. Lithuania, for example, has 0.82 percent of its population in uniform, whereas the United States and Germany have only 0.41 and 0.22 percent, respectively. Since joining NATO in 2004, Lithuania has increased the number of personnel in uniform by 70 percent.

Gaps and Geostrategic Vulnerabilities in Deterrence and Defense

The Baltic states have several major geostrategic vulnerabilities:

  • They lack strategic depth as a result of their small size. Whereas Ukraine has been able to defend in depth and use that depth to buy time for strengthening its defenses, the Baltic countries have no such option. Vilnius, for example, lies only 18 miles (30 kilometers) from the Belarusian border, where Russian forces are now based. For reference, Russia penetrated 152 miles (244 kilometers) into Ukraine in its attempt to capture Kyiv.
  • NATO reinforcements must travel long distances to get to the new frontline, as much as 10 times as far as during the Cold War.
  • The Suwałki Gap, running between Russia’s Kaliningrad enclave to the north and Russia-friendly Belarus to the south, constitutes a major vulnerability and the modern equivalent of the Cold War Fulda Gap. Russian missiles and artillery on both sides of the gap would create a gauntlet of fire in wartime for any NATO attempt to reinforce the Baltic states by land. Russia might even take the high-risk/high-payoff action of trying to close the gap with ground forces.

The inherent vulnerabilities and the small size of the Baltic countries and their militaries mean that, despite their extraordinary efforts, the Baltic states cannot defend the region without the help of the entire alliance.

Made in Madrid: NATO’s Commitments to Strengthen Defense and Deterrence

Russia’s 2014 aggression in Crimea and the Donbas indicated that the future might not be as peaceful as NATO had once hoped. In response, the defense budgets of NATO’s European members have risen by a third. Forward-deployed multinational battle groups were established in Poland, Lithuania, Latvia, and Estonia, putting more boots on the ground.

Russia’s invasion of Ukraine last year accelerated this process. At the Madrid summit, NATO members agreed on a new strategic concept—the alliance’s capstone policy document—that returned NATO to a Cold War–style strategy of forward defense through combat-ready forces deployed as far east as possible. To implement this new concept, the member states made several commitments to enhance defense and deterrence:

  • identifying Russia as “the most significant and direct threat to Allies’ security and to peace and stability in the Euro-Atlantic area”;
  • inviting Sweden and Finland to join the alliance;
  • setting a goal of expanding the battalion-sized battle groups (around 1,000 troops) to full brigades (up to 5,000 troops);
  • developing massive reinforcement forces (up to 300,000 troops ready at one month’s notice) and pre-positioned equipment in the Baltic region to speed deployment in a crisis; and
  • enhancing command and control, including establishing division-level structures.

However, implementation of the commitments NATO made at Madrid is lagging behind the rhetoric. Although allied defense spending continues to rise and NATO has implemented a robust exercise program to reassure allies and deter Moscow, divisions on defense spending continue, with most members not meeting the 2 percent goal. Progress on scaling up the existing Enhanced Forward Presence missions, strengthening regional plans, and generating reinforcement forces appears sluggish. One example is Germany’s ongoing struggle to deploy a full brigade in Lithuania despite having Europe’s largest economy and one of Europe’s largest militaries.

From Madrid to Vilnius: Closing NATO’s Deterrence Gap in the Baltics

Deterring a war is far better than fighting one, and the strongest deterrence comes from credible, forward-deployed forces. Other strategies might be less expensive and easier to implement but entail a high level of risk in the current environment. “Tripwire” strategies, for example, can be attractive in theory but dangerous in practice, as they rely on brinksmanship. The threat of retaliation may not be credible, and in the case of the Baltic countries, retaking territory is much harder than defending in the first place. Strategies relying on reinforcement need time to work, but time may not be available in a crisis. “Deterrence by detection” failed in Ukraine.

By focusing on the ability to deny a Russian fait accompli, NATO’s new strategic concept and the commitments made at Madrid set NATO on the right path for the future. Baltic officials often describe this approach as “repel, don’t expel.” In other words, defeat a Russian invasion; don’t rely on a counteroffensive after an initial withdrawal.

Yet slow progress in implementing the Madrid summit’s ambitious goals has rattled some allies and raised questions about NATO’s ability to carry through. At Vilnius, NATO leaders need to take action in several areas to enhance defenses and build credibility:

Provide the needed resources. The Defense Investment Pledge made by allies at the 2014 Wales summit was intended to be fulfilled “within a decade.” At Vilnius, member states need to start discussing what comes next since the decade ends in 2024. NATO will need a more aggressive push toward the 2 percent of GDP goal if member states are to provide the resources required by the new commitments and operating strategy. Many voices, including the Baltic countries, have advocated a higher goal—2.5 percent or even 3 percent. At the least, 2 percent should be a floor.

Build “robust in-place combat-ready forces.” For the Baltic states, implementing the new policy of forward defense to deter Russian aggression is critical for national security and indeed national survival. This requires decisions on several unresolved issues:

  • The nature of the forward-deployed brigades: Specifying “a brigade” is not enough. Decisions are needed regarding how large the brigades will be, which nations will provide the troops, how the brigades will absorb the existing battle groups, and where the brigades will get support troops.
  • The stationing of the brigades: Although it is easier to keep the bulk of the brigades at their home stations, they need to be forward deployed in peacetime to be a credible deterrent and meet the demanding timelines of a crisis.
  • The type and location of pre-positioned equipment: Pre-positioned equipment speeds force deployment but requires extensive peacetime preparation.
  • The divisional command structure: The lines of command are becoming unclear as Baltic states stand up their own division headquarters to replace NATO’s existing division headquarters. Building division headquarters capable of wartime operations requires equipment and trained personnel that the Baltic countries currently lack.
  • Enhanced exercise plans: New kinds of multinational capabilities need new kinds of NATO exercises.
  • The Suwałki gap: NATO needs to develop concepts for keeping the gap open in wartime and then make the appropriate peacetime preparations.

Refine and implement the new force model. At the Madrid summit, NATO committed to increasing its response force of high-readiness units from 40,000 to over 300,000 personnel through a new force model. While the initiative’s ambition is laudable, it got off to a bad start, with some allies surprised at the plan’s scale. At the Vilnius summit, NATO will reveal the status of this new force model one year from its conception. There are few signs that NATO will generate the massive forces required to meet the one-year deadline set by NATO’s secretary general.

Establish timelines and periodic reporting. The commitments need a clear timeline with assigned organizational responsibilities and designated milestones so that NATO can track progress. All future NATO summits and defense minister meetings (held quarterly) should include a status report from the secretary general on these actions.

Adapt the plan over time: Plans require continuous evaluation and adjustment. NATO, therefore, needs to periodically assess whether the new commitments are adequate in light of the evolving threat from an unpredictable Kremlin.

The Madrid summit put NATO on a new course to strengthen defense and deterrence in the Baltic region. The 2023 Vilnius summit is an opportunity to keep NATO on track to meet Madrid commitments.

Mark F. Cancian (colonel, USMCR, ret.) is a senior adviser with the International Security Program at the Center for Strategic and International Studies (CSIS) in Washington, D.C. Sean Monaghan is a visiting fellow with the Europe, Russia, and Eurasia Program at CSIS. Daniel Fata is a senior adviser (non-resident) at CSIS and former U.S. deputy assistant secretary of defense for Europe and NATO policy.

This commentary is based on a report funded by a grant from the Embassy of Lithuania.

Commentary is produced by the Center for Strategic and International Studies (CSIS), a private, tax-exempt institution focusing on international public policy issues. Its research is nonpartisan and nonproprietary. CSIS does not take specific policy positions. Accordingly, all views, positions, and conclusions expressed in this publication should be understood to be solely those of the author(s).

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