Historically, Sweden’s largest island, Gotland, has served as the most important strategic location in the Baltic Sea. For centuries, its value was defined by its ability to project power or provide sanctuary in an often-contested maritime region. However, following Sweden’s accession to NATO in 2024, the role of the island has undergone a fundamental transformation. The island transitioned from a defensive outpost for a non-aligned state to the most critical ‘unsinkable aircraft carrier’ for the Alliance on the northern flank. Consequently, Sweden and its Alliance partners are currently engaged in a rapid fortification of the island by integrating significant military infrastructure and high-end capabilities. Yet, as Gotland’s physical defences grow, a new geopolitical shadow looms. The uncertainty regarding future United States (US) involvement in European security creates a risk of emboldening Russian aggression, which makes Gotland’s role as a self-sustaining fortress critical for the stability of Northern Europe.
Gotland’s Strategic Geography
Gotland is situated in the centre of the Baltic Sea, located 300 kilometres from the Russian exclave of Kaliningrad. This position provides a strategic view over crucial sea and air corridors. From Gotland, fighter jets can reach the capitals of Estonia, Latvia and Lithuania in a matter of minutes. Therefore, the geographical setting makes Gotland an anticipated target in a Northern European wartime scenario. While Sweden possesses significant regional influence due to this location, the island is also vulnerable to targeted attacks. Its proximity to Russian military assets necessitates permanent high-readiness forces and early-warning systems to protect the integrity of the Swedish borders and the wider Alliance territory.
Furthermore, the current remilitarisation efforts represent a definitive reversal of Swedish policies adopted after the end of the Cold War. When the Soviet Union dissolved, the changed geopolitical landscape led Sweden to undertake major defence cuts. This policy of disarmament continued until the illegal annexation of Crimea in 2014. As a result, the escalating security situation has resulted in a significant shift in national priorities.
Remilitarisation and Procurement
In terms of regional dynamics, Finnish and Swedish NATO memberships have already reduced Russian naval and aerial freedom of movement in the Baltic region. Because NATO member states now surround the Baltic Sea, Russian access to the Atlantic Ocean is effectively blocked and its reach is confined to the Gulf of Finland. In this context, controlling the island is essential to prevent Russia from using its capabilities in Kaliningrad to sever the maritime and air corridors that connect the Baltic states to the rest of the Alliance. Sweden’s Chief of Defence, Michael Claesson, has warned that the threat from Russia is real and that an attack could happen without significant prior warning.
In June 2025, the Swedish government signed an agreement with the German defence manufacturer Diehl. This agreement involves the procurement of seven IRIS-T SLM (Surface-Launched Medium-range) air defence systems. The total value of the contract is approximately SEK 9 billion, and includes 49 vehicles with multifunction radar, command and control systems for airspace surveillance and targeting, two launchers with missiles, and support elements with vehicles for reloading, reserve parts and maintenance. In addition, Swedish forces have received modern military equipment such as CV90 armoured personnel carriers and Leopard 2 tanks. By building this standalone capacity, Sweden raises the costs of aggression for any adversary and buys necessary time for Allied reinforcements to arrive in the initial phases of a conflict.
Aurora 26
The Swedish-led military exercise Aurora 26 was a major milestone for regional cooperation, as it brought together 18,000 soldiers from 13 countries between 27 April and 13 May this year. The exercise utilised Finnish F-18 fighter jets, Dutch Apache helicopters and British snipers. The Swedish Armed Forces stated that the purpose of Aurora 26 was to strengthen defence capabilities in cooperation with allies and to practice dealing with a rapidly emerging military threat. Aurora 26 differs from previous exercises because it focuses on practicing new operational plans as a formal NATO ally. This involves host nation support and the execution of a Swedish invasion defence. A central focus was placed on logistics and the transport of heavy military capacity to and from the country. On Gotland, approximately 1,300 personnel from the US, Great Britain, Denmark and Ukraine participated in the final phase of the exercise on 11 May.
The Challenge of Political Uncertainty
NATO collective defence is the foundation of Sweden’s strategy to provide protection in a deteriorating security environment. However, there is a growing uncertainty within the Alliance as US President Trump has suggested a reduction in the US military presence in Europe. A reduced American presence would make the security situation in the Baltic Sea more dangerous. Russia might interpret a perceived weakening of the NATO alliance as an opportunity to pursue revisionist ambitions, as Russian strategic culture often prioritises territorial expansion and the establishment of spheres of influence.
Ultimately, if the US fluctuates in its commitment to European security, Sweden must ensure that Gotland is a permanent military fortress that can operate with a high degree of autonomy. The possibility of a US withdrawal from certain European security frameworks necessitates a stronger European pillar within NATO. Sweden and its Nordic neighbours must balance their national defence needs with the requirements of the Alliance. The fortification of Gotland is a geopolitical necessity to ensure that no security vacuum emerges in the Baltic region.
Conclusion
The transformation of Gotland from a demilitarised zone to a NATO fortress reflects the harsh reality of contemporary European security. The island is the pivot point upon which the stability of the Baltic region rests. While the procurement of IRIS-T systems and the success of Aurora 26 have bolstered defences, the long-term security of Northern Europe requires a consistent political commitment that accounts for both regional threats and global political shifts. Treating the seabed and the islands of the Baltic as a strategic frontline is essential for preventing future conflict. Sweden must continue to invest in its standalone capabilities while ensuring that Gotland remains fully integrated into the collective framework of the Alliance.
Recommended readings
Wieslander, (2021): https://www.tandfonline.com/doi/full/10.1080/14702436.2021.1955619
Zarembaite et al. (2023): https://www.atlanticcouncil.org/in-depth-research-reports/issue-brief/navigating-swedens-nato-membership-insights-for-political-and-operational-adaptation/#swedens-geography-and-defense-capabilities
Hånde, (2025): https://hdl.handle.net/11250/3205724