In June 2025, the European Commission (EC) concluded that the Adria pipeline had sufficient capacity to cover the entire demand of Slovakia and Hungary. Nine months later, after both countries had drawn on emergency stocks, they told the EC that tests were still needed to determine whether it could continuously cover the combined needs of their refineries.
Nothing in EU oil law had required that question to be answered in advance. That is the gap the revision of the Oil Stocks Directive should close.
Druzhba deliveries stopped: what happened
On 27 January 2026, crude deliveries through the southern branch of the Druzhba pipeline stopped. Hungary and Slovakia depend on the pipeline for most crude processed at both MOL’s Danube refinery and Slovnaft’s Bratislava refinery, which can together process around 14.2 million tonnes per annum (mtpa).
Slovakia declared an oil emergency on 18 February and authorised 250,000t of crude from state reserves. Hungary ordered the same amount released the next day. Their joint Council note on 13 March said that both countries’ stocks consequently fell below 90 days.
The alternative was seaborne crude landed at Omišalj and pumped inland through Adria. However, replacement supply remained “subject to the delivery capacity of the Adria oil pipeline”. Test results were still needed to determine whether the pipeline could provide continuous supply sufficient for both refineries’ combined needs; testing details remained under discussion.
The Commission remained confident. On 26 February, it reported no immediate security-of-supply risk and said additional cargoes at Omišalj would maintain supplies, consistent with its June 2025 assessment.
The disagreement was not about whether Adria existed. It was about what it could sustain. EU oil law provided no common ex ante method for settling that question.
Directive 2009/119/EC: what it verifies
Directive 2009/119/EC requires Member States to hold 90 days of net imports or 61 days of consumption. Stocks must be “available and physically accessible”, with arrangements for identification, accounting and control. Physical accessibility means arrangements for locating and transporting stocks. Annex III prevents double-counting and applies a flat 4% deduction to crude for naphtha yield, the only explicit conversion adjustment in the stock-counting rules.
The directive can therefore establish how much emergency crude exists, where it is held and whether arrangements exist for release and transport. It does not require a Member State to establish, before disruption, whether the shared chain that turns crude into needed products still works when a critical route fails. Article 20 requires contingency plans, but not such a test; Article 18 allows EC preparedness reviews.
Once crude qualifies as available and physically accessible, the rules do not discount it because conversion depends on a contested common route or constrained refining capacity.
Nameplate is not crisis capacity
Croatian statements have put Adria’s annual capacity at between 11mtpa and 15mtpa, but MOL says that no more than 2.2 million tonnes have ever moved through the relevant section in a year. MOL and JANAF publicly disagreed after joint tests in September 2025, when MOL said the required rate could not be sustained beyond one or two hours, while JANAF said it could meet both refineries’ full annual needs.
A ten-month test series launched in March 2026 shifted the question to stable, sustainable throughput. It also went beyond the pipe, covering port capacity, unloading speed and crude blending. MOL acknowledged that continuous peak-capacity testing had to await restoration of its damaged AV3 distillation unit. Refinery availability was part of the chain too.
By June, the Commission concluded that the disruption had “showcased the technical feasibility of the Adria pipeline”. Slovakia had maintained oil security, increased non-Russian flows and replenished emergency stocks. That does not remove the regulatory gap. The answer was demonstrated through a live disruption rather than a common ex ante resilience test.
Gas law already asks the security question
EU gas law uses a different security logic. Regulation 2017/1938 requires infrastructure to withstand the loss of the single largest gas infrastructure, while meeting exceptionally high demand. Risk assessments examine internal bottlenecks, cross-border flows and infrastructures that depend on a common upstream or downstream element, which cannot be operated separately and are treated as one.
That is the principle, not the formula. Gas is a network flow; oil involves crude grades, refinery compatibility, product yields and terminals. Copying N-1 arithmetic would be wrong, but borrowing its logic is not: identify shared bottlenecks before a crisis and test whether the regional chain still performs when a critical link is unavailable.
One narrow amendment to the Oil Stocks Directive
The Oil Stocks Directive does not need higher stock levels, mandatory refineries or a new EU capacity-licensing regime. It needs one addition to mandatory contingency planning under Article 20.
Where emergency supply depends on shared alternative infrastructure, the plan should include a regional stress assessment covering loss of the relevant common node, sustainable transport capacity, crude compatibility, realistically available refining throughput and product yield, and the ability to move products to market. The result should be tested against the combined needs of states relying on that node. Article 18 already provides a mechanism for Commission review.
The single market and global oil market remain the first line of defence. This test is for the narrower case where a physical bottleneck prevents substitution from arriving in time, particularly for landlocked, pipeline-bound refineries.
The Commission is consulting on the revision and, according to an internal consultation note seen by S&P Global, the crisis exposed “concrete operational failures”. No equivalent regional emergency supply infrastructure stress test appears in Commission materials that are publicly available or have so far been reported.
The 90-day rule should stay. What should change is what it is allowed to prove. In June 2025, the Commission assessed Adria as sufficient. In March 2026, Hungary and Slovakia were still seeking a common answer to what it could sustain continuously. By June, the Commission concluded that the disruption had demonstrated technical feasibility. Europe should not need a live supply crisis to answer that question.
A reserve should count as resilience only to the extent that the system can still turn it into supply after a critical link fails.
About the author: Ivo Hlaváček, Ph.D., was formerly a Slovak ambassador and director-general at the Slovak Ministry of Foreign Affairs. He has held senior advisory and supervisory board positions in the energy sector. He writes on energy security, geopolitics and international law, with a particular focus on energy markets, critical infrastructure, supply routes and the strategic dependencies they create.
