The Future of NATO’s Southern Flank

This series—featuring scholars from the Futures Lab, the International Security Program, and across CSIS—explores emerging challenges and opportunities that NATO is likely to confront after its 75th anniversary.

In the future, NATO must see its southern and eastern flanks as interconnected geopolitical spaces. Such a view necessitates adopting a holistic strategy that minimizes intra-alliance confrontations and builds deeper political integration with the southern flank.

The war in Ukraine has reinvigorated NATO. Two Nordic countries, Finland and Sweden, joined the alliance due to fears of potential Russian aggression, already imparting an air of success on NATO’s 2024 summit. However, many important debates about NATO’s future are on the agenda, including the alliance’s southern strategy, which the summit is tasked with formulating. The effectiveness of this strategy will depend on the alliance’s ability to perceive the eastern and southern flanks as interconnected geopolitical spaces.

Historically, NATO’s activity in the south has always lacked a coherent strategy and has been subordinate to the east. Member states have often found themselves supporting different strategies and actors in the south, and Russia’s aggression against Ukraine has further diverted attention to the eastern flank. Yet, this does not make the southern strategy any less important. Despite its geographical limits, the war in Ukraine directly influences the Mediterranean, the Middle East, and Africa. The past decade has shown that NATO’s eastern and southern regions share intertwined security dynamics, driven by Russia’s geopolitical maneuvers and China’s systemic competition.

Russia has long aimed to limit NATO’s access to the Mediterranean and to increase its presence in the region by building up its naval forces. These long-held ambitions are strongly tied to gaining a strategic position in the Black Sea. Putin built a Mediterranean squadron largely drawn from the Black Sea Fleet, which was strengthened by Russia securing critical ports in Abkhazia and Crimea. For Russia, the ability to move maritime assets freely between the Black and Mediterranean Seas has been key in undermining the positions of NATO members in both regions. By the same token, the war in Ukraine led to the shrinkage of Russia’s naval presence in the Mediterranean after Turkey closed the Bosphorus and Dardanelles straits to warships in 2022. The future of Russia’s military footprint in the south will depend on Russia’s interoperability between the two regions.

Despite NATO being a regional alliance and China not being considered as an enemy, the systemic challenges posed by China require NATO to develop a strategy that integrates both the eastern and southern flanks. The possibility of an Indo-Pacific conflict is already reshaping the character of Euro-Atlantic security, with significant implications for U.S. defense and alliance commitments. Such a conflict would strain U.S. resources, leaving the European pillar of the alliance to assume greater responsibility for geopolitical threats. In a similar vein, war in Ukraine has increased alignment between China and Russia, leading to a systemic shift in the threat landscape.

Moreover, China’s economic integration through strategic investments in countries on NATO’s southern flank is part of a larger policy that increases dependency on China in key sectors such as critical infrastructure, minerals, supply chains, and areas such as telecommunications and clean tech. This dependency will need to be addressed by the alliance moving forward, especially as Europe scales up defense production reliant on these investments. Furthermore, the instability and hybrid threats emanating from both state and non-state actors are directly associated with Russia’s and China’s expanded influence along NATO’s southern border. Through private military companies, Russia holds an informal military presence in Libya and the Sahel. Traditionally, the eastern flank is considered to face more conventional threats, while the southern flank is associated with diffuse and nonconventional threats. However, China’s economic might and Russia’s military influence are intertwining these threat areas.

To address this, NATO’s future strategy must integrate its eastern and southern approaches through a cohesive framework. Considering the southern and eastern flanks as a single, intertwined geostrategic space necessitates a holistic strategy—one that avoids previously divided policy domains and favors intra-alliance coherence. There are several considerations for NATO in this regard.

First, geopolitical stability on the southern flank is directly linked to making the current thaw between two members, Greece and Turkey, permanent. This is why Greco-Turkish relations should be situated in a systemic framework that addresses their sovereignty issues. By leveraging recent energy cooperation between the neighbors, the alliance can develop a framework that keeps the power balance intact and limits any risk of escalation due to domestic political pressures. NATO should push for an inclusive solution in the Eastern Mediterranean to free up resources that member states currently dedicate to conflicts with each other, allowing these resources to be used for stronger collective positioning against adversaries.

Second, NATO’s ability to project stability to the south depends on increasing interoperability across both flanks. Operation Sea Guardian is already key to enhancing maritime situational awareness, but further maritime security capacity building among partners will be crucial to limit Russia’s operational capabilities. In line with this, the alliance should start honest discussions on crisis management in Libya, given its strategic importance to countering Russia’s influence and improving regional stability.

Third, the growing influence of China and Russia in the Middle East and Africa, along with systemic risks, impresses upon NATO the need to develop a long-term perspective for these regions. While terrorism and immigration will likely be important elements of the strategy, it should not be confined to them. Overemphasis on security-related approaches has proven futile to NATO’s interests. Countries in Africa and the Middle East are seeking mutually beneficial solutions that promote economic growth and capacity building. Therefore, NATO should prioritize building deeper political and economic relations with African and Middle Eastern states. Such an approach will address heightened perceptions of Western double standards regarding international humanitarian law, particularly highlighted by the ongoing conflict in Gaza, on which Russia and China are capitalizing. This strategy will also help build resilience against China’s strategic investments by reducing dependency and fostering local development.

This holistic approach will have implications on the European defense industrial base. As pressures grows to strengthen the European pillar of the alliance, non-EU members and NATO partners in the Middle East can be part of Euro-Atlantic security discussions. Such an approach can also ease relations between Turkey and the European Union, thereby strengthening EU-NATO engagement.

An active southern strategy will make NATO stronger by reinvigorating the alliance and including southern partners in Euro-Atlantic security discussions. This will put European security in a broader perspective, addressing not only Russia’s eastern aggression but also providing stability in the south.

Yasir Atalan is an associate fellow at the Futures Lab at the Center for Strategic and International Studies in Washington, D.C.