The Implications of Sweden and Finland’s NATO membership for Deterring Russia in Europe

Introduction
NATO's eastward enlargement and Russia's ambitions in Europe have precipitated major crises in the international arena. In this context, Russia's annexation of Crimea in 2014 marked a significant turning point in the conflict with the West, bringing efforts to deter Russia back into sharp focus. This event was preceded by the 2008 conflict over South Ossetia and Abkhazia, which had already drawn international attention to the escalating tensions. The persistence of these tensions culminated in Russia's full-scale invasion of Ukraine in February 2022. The war continues to this day, with parts of eastern and southeastern Ukraine under the control of the Russian army. In response to Russia's actions, NATO has implemented a range of measures. A significant part of this strategy focuses on strengthening countries in Russia's neighborhood, which are more vulnerable and constitute the alliance's front line. A key manifestation of this strategy is the accession of Finland and Sweden to the North Atlantic Treaty in April 2023 and March 2024, respectively.
An essential aspect of this development is that both Sweden and Finland had historically maintained a policy of neutrality, which allowed them to pursue security cooperation while avoiding direct entanglement in West-Russia conflicts and their associated risks. Sweden had upheld this stance since the Napoleonic Wars, and Finland since 1948, to the extent that many scholars considered neutrality a core component of their national identities. However, fundamental shifts in the European security environment prompted a significant reassessment in both nations, convincing policymakers and public opinion that the policy of neutrality was no longer sustainable. This article examines the implications of this strategic reorientation for NATO's deterrence posture against Russia. The central research question it addresses is: What impact does the accession of Sweden and Finland to NATO have on the alliance's ability to deter Russian aggression? To answer this question, the article will also provide a historical background of their neutrality and analyze the specific factors that led to this pivotal change in policy.
 
The Research Method
This article employs a case study methodology. Data was collected using a documentary method, drawing from a variety of sources including scholarly articles, books, and public statements by officials reported in the media. The analysis is guided by the theoretical approach to deterrence developed by Alexander George and Richard Smoke. This framework facilitates a systematic, multi-level analysis by connecting various factors, making it particularly suitable for examining complex, multifaceted cases such as this one.
Discussion and Results
As previously stated, the theoretical framework of deterrence developed by Alexander George and Richard Smoke is applied to answer the research question. The study's hypothesis is that the accession of Finland and Sweden to NATO will enhance the West's deterrent power against Russia by creating new strategic conditions. These conditions include the extension of NATO's security guarantees—specifically Article 5 on collective defense—increased combined military capability, a more favorable geopolitical position for the alliance, and a clear warning to Russia that any hostile action will incur serious consequences. A key novelty of this work, in comparison to other studies in the field, is its specific emphasis on the concept of deterrence in relation to Finland's and Sweden's accessions. It pays particular attention to the consequences this membership has for the evolution of deterrence against Russia in the European theater.
In the deterrence framework developed by Alexander George and Richard Smoke, several factors are critical for effectiveness, and this article adapts these components to the present case study. Regarding defense and security capabilities, the analysis demonstrates that Sweden and Finland's accession to NATO reciprocally enhances the alliance's military strength. Although both nations had significant prior cooperation with NATO, their formal membership sends an unequivocal message about the collective seriousness in countering Russian threats, thereby bolstering the credibility of deterrence. However, it has been suggested that the inclusion of formerly neutral actors, who may have previously maintained reasonable relations with Russia, could potentially have the opposite effect, creating challenges for the perceived unity and resolve of NATO members. Despite this concern, other experts contend that Sweden and Finland have a proven history of managing Russian threats independently, and their membership represents a mutual benefit that strengthens both the alliance and the two nations.
Within George and Smoke's approach, historical and geopolitical contexts, along with the perceptions actors hold of one another, are also vital. From this perspective, the accession of Sweden and Finland provides NATO with a strategically advantageous position, which is geopolitically significant. Conversely, some analysts, citing the security dilemma and considering Russia's historical context and perceptions, argue that this expansion will increase regional tensions. Others, pointing to precedents like Russian threats and the deployment of nuclear weapons in Kaliningrad, reject this claim, viewing the memberships as a necessary step to counter an existing and demonstrated threat.
Conclusion
In light of this article's analysis, it is evident that the accession of Finland and Sweden generally enhances the deterrence capabilities of Western actors against Russia. However, the findings also indicate that the realities of the historical context and Russia's perception of Western actions may inadvertently fuel an arms race and intensify the security dilemma.