The European Commission’s Staff Working Document SWD(2025) 435 represents the first comprehensive fitness check of the EU’s modern energy-security architecture, assessing how the Gas Security of Supply Regulation and the Electricity Risk-Preparedness Regulation functioned under the stress of the 2021–2023 energy crisis and how they will need to evolve in a structurally different energy system. While the document is formally focused on EU Member States, its findings are directly relevant to Southeastern Europe, a region that is physically, commercially, and operationally embedded in the EU energy system but remains institutionally fragmented between EU members, accession candidates, and Energy Community contracting parties.
For Southeastern Europe, the document is not a theoretical regulatory exercise. It is effectively a forward-looking map of how the rules governing cross-border gas flows, electricity security, emergency coordination, infrastructure resilience, and sector coupling will tighten over the coming decade, and how countries on the EU’s periphery will be expected to align in practice even before full membership. The analysis embedded in SWD(2025) 435 clarifies why SEE can no longer be treated as an external appendage to EU energy security, but as an internal stability buffer whose weaknesses increasingly translate into systemic risk for the wider European market.
The starting point of the Commission’s assessment is that the core objectives of the EU energy-security framework remain valid. Ensuring continuity of supply, preventing unilateral crisis responses, and embedding solidarity across borders are still considered essential. What has changed is the operating environment. Gas demand is structurally declining but remains critical for power balancing and industry. Electricity systems are becoming more weather-dependent, more digital, and more exposed to cascading failures. Infrastructure has become not only a physical asset but a strategic and cyber-vulnerable one. In this context, the experience of Southeastern Europe during the crisis years is implicitly woven throughout the document, even when the region is not named explicitly.
One of the most important findings for SEE concerns regional risk planning. The Commission concludes that the introduction of mandatory regional risk groups and joint risk assessments under the gas security framework materially improved preparedness and reduced the temptation for purely national crisis measures. This matters for Southeastern Europe because the region’s gas and power systems are, by design, cross-border systems. Serbia’s gas security cannot be separated from Hungary, Bulgaria, and Bosnia and Herzegovina. North Macedonia’s electricity stability is structurally linked to Greece and Bulgaria. Montenegro’s system stability depends on regional hydrology and interconnections with Serbia, Bosnia and Herzegovina, and Italy. The fitness check implicitly validates the regional logic that SEE planners have long argued for but often lacked political backing to implement consistently.
During the crisis, the EU framework constrained unilateral export bans, forced transparency on storage and demand-reduction measures, and created predictable coordination channels. For Southeastern Europe, this experience underscores a critical point: alignment with EU-style regional risk planning is no longer optional if the region wants stable access to cross-border flows in stress conditions. The document signals that future revisions of EU security legislation will deepen these regional obligations, not dilute them, and that neighbouring systems will be expected to operate on compatible assumptions, data standards, and crisis scenarios.
Gas infrastructure flexibility is another area where the document has direct SEE relevance. The Commission identifies reverse-flow capabilities, interconnectors, and shared use of storage as decisive in avoiding physical shortages during the crisis. This assessment directly intersects with Southeastern Europe’s historical vulnerabilities. Much of the region entered the crisis with legacy, single-direction pipelines and heavy reliance on a limited number of entry points. While emergency measures and ad-hoc arrangements mitigated the worst outcomes, SWD(2025) 435 makes clear that future security policy will be less tolerant of structural rigidity.
For SEE governments and utilities, this reinforces the strategic logic of bidirectional interconnectors, regional storage access agreements, and operational harmonisation with EU transmission system operators. It also reframes gas infrastructure investment not as a contradiction to decarbonisation, but as a risk-management tool in a system where gas remains the marginal stabiliser for power systems with high renewable penetration. The document hints that future EU rules may increasingly integrate gas security planning with hydrogen readiness and low-carbon gases, a development with significant implications for Southeastern Europe’s pipeline networks and storage assets.
Electricity security emerges in the fitness check as the weaker leg of the current framework. The Commission is explicit that electricity risk-preparedness has lagged gas security in terms of maturity, enforcement, and integration with long-term adequacy planning. This finding is particularly significant for Southeastern Europe, where electricity systems are undergoing rapid change. Hydropower-dependent countries face increasing climate variability. Thermal fleets are ageing and exposed to carbon costs. Renewable capacity is expanding faster than grid reinforcement in several jurisdictions.
The document stresses that electricity security can no longer be treated as a short-term emergency issue. Instead, it must be embedded in long-term system adequacy, cross-border capacity planning, and operational coordination. For SEE, this implies that participation in ENTSO-E planning processes, regional adequacy assessments, and coordinated outage planning will become increasingly binding in practice, even for non-EU members. The fitness check’s emphasis on spillover effects between gas and electricity systems is particularly relevant in a region where gas-fired generation often serves as the primary balancing resource for renewables and hydropower volatility.
A recurring theme in SWD(2025) 435 is the need for better cross-sector integration. The Commission acknowledges that existing frameworks still treat gas and electricity security largely in silos, despite clear interdependencies. For Southeastern Europe, this observation reflects lived experience. Gas supply disruptions translate rapidly into power-sector stress. Drought conditions affect hydro output and increase gas burn. Heatwaves simultaneously raise electricity demand and constrain thermal generation. The document’s call for integrated risk scenarios aligns closely with the region’s structural realities and suggests that future EU guidance will require more sophisticated modelling that captures these feedback loops.
Administrative capacity and reporting burdens are addressed in the fitness check in a way that is particularly relevant for SEE regulators and ministries. The Commission recognises that while reporting and simulation requirements improved preparedness, they also created complexity and duplication. For Southeastern Europe, where institutional capacity is often thinner than in core EU Member States, streamlined and standardised processes could materially improve compliance and effectiveness. At the same time, the document signals that simplification will not mean lower expectations on data quality or transparency. On the contrary, better data sharing and digitalisation are presented as prerequisites for more efficient oversight.
Beyond the core gas and electricity regulations, the fitness check situates energy security within a broader resilience framework. Critical infrastructure protection, cybersecurity, and the resilience of essential entities are highlighted as increasingly central to supply security. For Southeastern Europe, this has far-reaching implications. Transmission grids, substations, compressor stations, and digital control systems are not only technical assets but strategic targets in a more volatile geopolitical environment. Alignment with EU standards in these areas will increasingly shape access to cross-border support mechanisms, emergency assistance, and financing.
Perhaps the most important signal for Southeastern Europe lies in the document’s forward-looking conclusions. The Commission states explicitly that while the objectives of the current framework remain valid, adaptation is unavoidable. Decarbonisation, electrification, sector coupling, and geopolitical fragmentation will require new instruments, revised obligations, and deeper coordination. For SEE, this means that the window for passive alignment is closing. Energy security rules developed in Brussels will increasingly define the operational conditions of the regional market, regardless of formal membership status.
In practical terms, SWD(2025) 435 positions Southeastern Europe as both a beneficiary and a test case of the next phase of EU energy security policy. The region stands to gain from deeper integration, more resilient infrastructure, and clearer crisis-management rules. At the same time, its structural vulnerabilities, investment gaps, and institutional asymmetries make it a focal point for the very risks the Commission is seeking to mitigate. The document implicitly recognises that EU-level energy security cannot be achieved if neighbouring interconnected systems remain weak links.
For policymakers, utilities, investors, and system operators in Southeastern Europe, the message of the fitness check is unambiguous. Energy security is no longer a national or even regional issue; it is a system-wide condition governed by shared rules, shared data, and shared responsibilities. The evolution of the EU framework outlined in SWD(2025) 435 suggests that the region’s strategic choice is not whether to align, but how quickly and coherently it can do so while preserving flexibility for its specific economic and structural constraints.
Seen through this lens, the document is less a retrospective assessment and more a strategic warning. The next energy crisis may not resemble the last one, but the Commission’s analysis makes clear that preparedness, regional solidarity, and system resilience will define which parts of Europe absorb shocks and which amplify them. For Southeastern Europe, integration into the EU energy-security architecture is no longer a future aspiration. It is becoming a present-day requirement embedded in the physics, economics, and governance of the continental energy system.