For two decades, Europe believed that liberalised gas markets, diversified suppliers and rules-based infrastructure would guarantee stability. That illusion collapsed with Russia’s war in Ukraine. What followed was the most dramatic gas restructuration seen in modern Europe: supply routes redrawn, LNG capacity rushed into existence, pipeline politics replaced by resilience politics, and gas transformed from an invisible commodity into a central security and economic determinant. For Western and Northern Europe, this transformation has largely stabilised. South-East Europe remains caught between old dependence and new uncertainty, simultaneously integrating into Europe’s gas security architecture and living closer to vulnerability than almost any other region on the continent.
Europe’s gas market today is no longer built on Russian pipeline confidence; it is built on diversification, LNG flexibility, European solidarity mechanisms and emergency resilience frameworks. Gas is now treated as an element of continental survival rather than a comfort commodity. In SEE, however, memory and reality collide. The region has historically depended on single-supplier logic, politically influenced pricing models and infrastructure chains that reflect geopolitics more than rational economics. That legacy has not disappeared. It continues to shape vulnerability and decision-making.
Yet the same crisis that exposed South-East Europe’s risks also forced its strategic awakening. New LNG terminals in Greece, expanded use of the Revithoussa terminal, the emergence of Alexandroupolis, growing regional interest in Ionian-Adriatic corridors, greater North-South integration and reinforcement of interconnectors have begun to rewrite the region’s energy geography. SEE is no longer simply a downstream recipient of whatever pipeline politics dictate. It is becoming a testing ground for whether Europe’s new gas resilience logic truly includes the Balkans or simply stabilises the core while peripheral regions remain structurally exposed.
The central reality today is that SEE and the EU remain deeply interdependent on gas — but increasingly in complex forms. Europe depends on SEE as a transit zone, a flexibility region, a security buffer and a market whose stability affects continental risk exposure. SEE depends on the EU for infrastructure financing, diversification routes, regulatory frameworks, coordinated market confidence and geopolitical cover. Neither can claim insulation. The region’s stability is part of Europe’s stability. Europe’s credibility depends on not leaving its southeastern flank exposed.
Country-level realities illustrate how uneven, fragile and strategically decisive this interdependence actually is.
Serbia remains emblematic of historical dependence layered on emerging adaptation. Long reliant on Russian gas via established routes, Serbia has had to navigate a security environment where continuity could no longer be assumed. Belgrade now finds itself balancing pragmatism with necessity: maintaining supply security, preserving affordability and preventing industrial shock while simultaneously recognising the dangers of single-source reliance. Interconnector development, regional storage capacity relevance and connections toward Hungary, Bulgaria and the Adriatic architecture are no longer optional policy choices; they shape whether Serbia remains trapped in dependency logic or evolves into a hedged, strategically resilient gas actor.
Bulgaria represents one of the most transformative recent case studies. Once deeply exposed to Russian supply disruptions, it was forced abruptly into diversification. The interconnector with Greece and access to new LNG-based gas reshaped its position. At the same time, Bulgaria sits at a politically sensitive midpoint of European gas flows. Decisions taken in Sofia have implications far beyond national borders. Bulgaria is both a vulnerability transmitter when unstable and a strategic stabiliser when aligned. Europe expects Bulgaria to mature into the latter.
Greece, by contrast, has become one of the region’s most proactive energy actors. While electricity reform defined one dimension of its transition, gas has reshaped another. LNG infrastructure development created not just national resilience, but regional relevance. Greece is no longer only an importer; it is increasingly an enabler of SEE diversification. If Alexandroupolis and associated transmission capacity continue to mature, Greece becomes an anchor of supply security rather than a peripheral beneficiary of others’ stability. Its role in the gas map of SEE is no longer marginal; it is foundational.
Hungary remains structurally gas-dependent and politically careful. While physically interconnected and theoretically capable of diversification, its gas policy remains intertwined with its political calculus and pragmatic security priority: secure volumes at stable prices. This pragmatic position shapes regional gas behavior. It sends strategic signals, influences negotiation behaviours and shapes long-term infrastructure logic. Hungary’s direction helps determine whether the region collectively normalises diversification or gradually drifts back into dependency comfort when crisis memory fades.
Romania stands apart as the region’s most structurally advantaged player — and its most underutilised one. With domestic production capabilities and Black Sea potential, Romania has the rare possibility to reduce exposure not merely through diversification, but through indigenous production strength. This could reshape the gas map of SEE entirely. If Romania fully maximises its production opportunity while maintaining European alignment, it becomes a pillar of regional supply security. If it hesitates under political hesitancy or administrative paralysis, a defining chance is lost.
Bosnia and Herzegovina remains deeply exposed, limited in infrastructure and constrained by political fragmentation. Its internal governance challenge translates directly into gas insecurity. Without systemic coherence, gas becomes another instrument trapped inside political division instead of functioning as a strategic national asset.
North Macedonia faces a simple but harsh reality. Without diversified routes and secure interconnections, gas supply risk translates directly into macroeconomic and social risk. Price surges and availability shocks do not enter as theoretical geopolitical debates. They enter as household affordability crises, industrial competitiveness shocks and political stress events.
Montenegro sits at an interesting margin of this discussion. Smaller and less structurally dominated by gas dependence than many neighbours, its strategic positioning lies not in large consumption but in its potential integration role into emerging Southern Corridor and Adriatic diversification frameworks.
Overlay Europe on top of these narratives and the discussion shifts from regional weakness to continental consequence. If SEE remains structurally fragile on gas, Europe’s security framework is incomplete. If SEE integrates fully into diversification routes, LNG-backed supply logic and coordinated resilience systems, the continent stabilises far beyond simple consumption metrics.
The broader strategic transformation is now clear. Europe is moving toward a gas system that is less Russian, more flexible, more expensive structurally than before, but significantly more secure. SEE cannot afford to be the exception. Electricity showed that integration equals stability. Gas demonstrates that vulnerability spreads if not contained.
The future will not necessarily see gas disappear overnight. Even as Europe accelerates renewables, hydrogen prospects and electrification, gas remains part of industrial continuity, heating security and transition balancing. That means SEE’s gas evolution is not a temporary topic. It is a defining strategic question for at least the next decade.
If the region completes diversification, strengthens interconnectors, unlocks Romania’s production, anchors Greek LNG as regional stabiliser, harmonises regulation and normalises European gas behaviour, it will finally shed its reputation as Europe’s energy weak point. If not, it remains a pressure zone where geopolitics, economics and vulnerability intersect too easily.
The fundamental truth is that South-East Europe and the European Union are not spectators in each other’s gas stories. They are co-authors. The way gas is managed, diversified, governed and politically handled in SEE will not merely shape local realities — it will influence continental resilience, market confidence and strategic positioning for years ahead.
As with electricity, the question is not whether SEE can align with Europe’s new gas era. It is whether it chooses to do so while time is still a strategic advantage rather than a crisis-driven necessity. Integration brings security. Dependency brings exposure. The space between those two conclusions is where the region now stands.