The process of expanding the membership of the North Atlantic Treaty Organization (NATO) has been a consistent feature of US policy towards Russia since the fall of the former Soviet Union. This expansion has contributed to shaping Moscow's perceptions of its security requirements and had a profound impact on relations between East and West. What was proven is that Russia's opposition alone is not sufficient to stop this expansion, as the West has treated this opposition as remnants of outdated Soviet ideology. With the start of the war in Ukraine on February 24, 2022, the Western perspective that NATO expansion is a more logical means of deterring Russia, which has become a dangerous threat to Europe once again, has become even stronger.

In a strategic and historic turn, and in one of the fastest membership processes in the recent history of NATO, Finland has become the 31st member of the military alliance after it submitted its request in May 2022. Alongside Norway, the three Baltic republics, and Poland, Finland will become the sixth NATO member that shares borders with Russia. With Finland becoming the newest member of the alliance, the shared border between NATO and Russia has doubled, as the two countries shared a border spanning 1,340 km, which is undoubtedly a worrying development for Moscow. On April 4, 2023, Finland officially joined NATO, coinciding with the 74th anniversary of the signing of the Washington Treaty that established the alliance in 1949. Moreover, Finland’s membership comes about three months before the NATO Summit, scheduled for July 2023 in Lithuania.

Reinforcing NATO

There is a consensus among strategic and security experts in the West that the full membership of Finland, and later Sweden, in NATO, would represent a significant addition to the alliance, given their geostrategic location, military capabilities, and political orientations that align with other members of the alliance. In this regard, the following considerations should be noted:

1- Finland’s, and later Sweden’s accession, to NATO is a major shift in European security:

This will provide the alliance with an additional advantage that will enhance its material capability. The two countries will become security service providers and will particularly contribute significantly to burden-sharing among allies and the strengthening of NATO's ability to upgrade its planning and develop its defense capabilities.

2- The two countries’ NATO membership is set to enhance the alliance’s deterrence and Europe’s security:

Their accession will significantly complicate Russia’s military planning in the Baltic region. Moreover, Finland, which has compulsory military service, has significantly increased its defense budget by 54% in 2021, and committed an additional USD 2.2 billion in the wake of the war in Ukraine.

3- Western Experts believe that participating Finnish troops will be tasked with defending NATO’s northeastern flank:

Such a task will create an integrated strategic space for the alliance in the North, and help unify the northern European region and cover the entire Baltic Sea, as well as the far North, and most likely the North Pole and the High North.

4- Accordingly, Finland will contribute strategic coastal defense capabilities:

This contribution entails a high-capacity air force, including a large fleet of F-35 Joint Strike fighters starting from 2026, a ground force considered large by today’s standards, long-range artillery systems such as the HIMARS ( High Mobility Artillery Rocket System), in addition to significant capabilities to compete in the Arctic.

5- Both countries are unlikely to send large numbers of troops to NATO:

According to some NATO experts, because of Russia's direct threat to the sovereignty of Finland and Sweden in the Baltic states and the northeastern part of the Scandinavian Peninsula, the governments of both countries are unlikely to agree to send large numbers of troops to missions that are not directly related to confronting the Russian threat. That is because it will be difficult for both states to convince the public to participate in operations outside Europe, especially in light of their disappointing experiences, where they had a presence alongside NATO in Afghanistan, and Finland participated in the European Union Training Mission in Mali, or EUTM Mali.

It is noted here that Finland and Sweden's pursuit of joining NATO did not begin until after Russia's military intervention in Ukraine, which posed a direct threat to both countries. In their view, joining NATO is a purely defensive step taken to protect the eastern wings of both countries and keep Russia away from the Baltic states and Eastern Europe.

6- Variant political and military engagement among NATO members:

Although all NATO members contribute to collective defense, which is a fundamental principle of the alliance, the levels of political and military engagement for each member vary significantly. Unlike the United States, which remains the backbone of the alliance because of its commitment and ability to project significant military power across the entire European/Atlantic theater of operations, many smaller members - including Finland - seek to play a limited role, whether in terms of geographic focus or the size of troops.

Moscow’s Options

 In statements made on April 4, 2023, Russian Defense Minister Sergey Shoygu said Finland's accession to NATO was a "dangerous historical mistake that will weaken security in the wider region and increase the risk of conflict and will force Moscow to take countermeasures." He added that Russia would form twelve units and brigades in its western military zone.

Russian news website Ria Novosti quoted Russian Deputy Foreign Minister Alexander Grushko as saying "If forces and assets of other members of the (NATO) alliance are deployed in Finland, we will take additional steps to reliably ensure Russia's military security." In a related context, NATO Secretary General Jens Stoltenberg stated that the alliance does not intend to immediately enhance its presence in Finland.

The statements of the Russian official and NATO chief reflect the fact that Finland's accession process was fast-paced at a time when the alliance is actively and strongly engaged in supporting Ukraine, leaving little room for difficult discussions between the new member and the alliance on various issues, particularly the practical aspects of defending Finland, strategic planning for any potential war, logistics, and tactics. Specifically, the intention here is to determine the necessity for allies to have the plan to defend the new member, as reliance on NATO's defensive commitment stated in Article 5 of the Washington Treaty alone should not be sufficient, as this article does not automatically deter aggression. That is, once the council of the alliance decides that an attack has occurred and must be responded to under Article 5, the members then make a decision on the appropriate response, and each of them individually decides how to contribute to this response. Since decision-making in NATO is based on consensus, fulfilling the first two thresholds to take action under Article 5 is not guaranteed.

It is worth noting that since the beginning of discussions about Finland and Sweden joining NATO at the start of the Ukrainian conflict, senior Russian officials stated that they will have "technical military" responses to this accession, but they provided no further details. Moscow has previously conducted maneuvers using road-mobile anti-aircraft missiles and deployed S-400 missile systems, anti-ship missiles, as well as hypersonic missiles.

Most estimates by Western experts note that in the current war circumstances, Russia will either have to significantly increase the size of its army, which will be difficult given its current economic conditions, or re-deploy forces from the southern, central, or eastern military zones to the Baltic region, which is unlikely due to existing requirements to defend the Caucasus region. One likely and possible solution for Russia would be to announce new deployments of Iskander ballistic missiles, dual-capable road-mobile cruise missiles, hypersonic missiles, anti-aircraft missiles, anti-ship missiles, as well as tactical nuclear weapons in Kaliningrad and St. Petersburg.

This measure would marginally increase the stockpiles already deployed in the region, which Moscow may now openly acknowledge. It is known that Russia already possesses significant military assets in Kaliningrad, around St. Petersburg, and the Kola Peninsula. These include highly alert and capable ground, air, and naval forces, as well as a collection of dual-capable ballistic missiles and cruise missiles that can operate in the air, sea, and land. In addition, the Kola Peninsula is used as a major hub for Russian naval operations, including operations of its nuclear submarine fleet, in the Arctic and the northern Atlantic Ocean.

In fact, Belarus' announcement on March 28, 2023, of deploying Russian tactical nuclear weapons on its territory is part of Moscow's response to Finland's, and later Sweden’s joining NATO. Belarus shares borders with Poland, Lithuania, and Latvia, and is in close proximity to the Russian enclave of Kaliningrad.

Assessments suggest that Moscow's potential actions are unlikely to significantly alter the strategic balance in the region or significantly complicate NATO's defense planning with Finland and Sweden. The alliance will avoid provoking Russia without cause. Experts conclude that unless Moscow resorts to serious, direct and credible threats, Finland and Sweden will avoid establishing permanent bases for the alliance or deploying nuclear weapons on their territory because they do not possess nuclear weapons, are signatories to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), and have a strong tradition of supporting identification and non-proliferation of nuclear weapons. Finland, for its part, may also avoid a significant increase in NATO's large-scale exercises on its own territory.

To conclude, Finnish policymakers are unlikely to increase Finland’s involvement in NATO’s operations, at least in the short term, given the country’s strategic needs and the potential political and material costs that might be incurred. Finland’s geography and military traditions serve more restrictions. Unlike Sweden, Finland shares a long border with Russia. Additionally, the absence of natural obstacles along the border, other than forests, makes the country particularly vulnerable to Russian threats, which will require it to prioritize defending its territory while also exercising restraint and avoiding provocation at the same time. This only requires a very limited amount of change in its current policies.