A former Ukrainian special forces officer has gone on trial in Hamburg over the 2022 Nord Stream explosions, with his lawyers arguing that Russian energy infrastructure used to finance aggression cannot automatically enjoy protection as a civilian installation.

The first criminal trial arising from the destruction of the Nord Stream gas pipelines has opened in Hamburg, confronting German judges with allegations against a former Ukrainian military officer and a dispute over whether Russian energy infrastructure constituted a legitimate wartime target.

Serhii Kuznietsov, 50, is accused of organising an operation that destroyed three of the four Nord Stream pipeline strands in the Baltic Sea in September 2022. German prosecutors have charged him with offences involving explosives, damage to infrastructure and participation in a war crime.

At the opening hearing on 14 October, Kuznietsov’s lawyers sought to have the proceedings dismissed, challenging both the evidence against their client and the prosecution’s classification of the pipelines as protected civilian infrastructure.

According to the account of the opening proceedings, the defence argued that the installations served Russia’s strategic interests and had been used to exert economic and political pressure on European countries.

Kuznietsov denies involvement in the explosions. His lawyers maintain that the prosecution has not established that he participated in, let alone directed, the operation.

German prosecutors allege Ukrainian involvement

The explosions occurred on 26 September 2022, approximately seven months after Russia launched its full-scale invasion of Ukraine.

Underwater detonations near the Danish island of Bornholm ruptured sections of Nord Stream 1 and Nord Stream 2, releasing large quantities of natural gas into the Baltic Sea.

German investigators allege that a group of Ukrainians used a rented sailing yacht, the Andromeda, to transport divers, explosives and equipment to the pipelines.

According to the prosecution, the operation involved military-grade explosive devices and was organised with the knowledge or direction of Ukrainian state authorities.

These allegations remain to be tested in court. Ukrainian officials have denied state involvement, and no German judicial finding has established responsibility on the part of Kyiv’s political or military leadership.

The defendant was arrested in Italy in August 2025 and subsequently extradited to Germany following lengthy legal proceedings.

As EU Today reported following the Italian Supreme Court’s ruling, Kuznietsov’s defence had challenged the legality of his transfer and questioned the evidence underpinning the German investigation.

His appearance in Hamburg now moves the case from extradition disputes to direct examination of the prosecution’s allegations.

Can a gas pipeline be a military target?

The central legal controversy concerns whether the Nord Stream infrastructure was entitled to protection as a civilian installation during an international armed conflict.

Under international humanitarian law, civilian objects are generally protected against attack unless their nature, location, purpose or use makes an effective contribution to military action and their destruction offers a definite military advantage.

Kuznietsov’s defence argues that Nord Stream had served Russian strategic interests by generating energy revenue and providing Moscow with leverage over European governments.

Defence lawyer Nicola Canestrini has described the pipelines as an instrument of Russian economic coercion rather than infrastructure serving an exclusively civilian purpose.

German prosecutors reject the proposition that those circumstances automatically justified their destruction. They maintain that the operation involved attacks against civilian infrastructure and therefore constituted a war crime.

The legal assessment is more complicated than determining who owned the pipelines.

Financial benefits to a belligerent state do not necessarily make every commercial installation a military objective. Equally, civilian ownership or use does not automatically exclude infrastructure from becoming a military target if the conditions established under the laws of armed conflict are satisfied.

The operational circumstances in September 2022 could become important. Nord Stream 1 had already ceased delivering gas, while Nord Stream 2 had never received German certification to begin commercial operations.

The court will therefore have to consider both the pipelines’ strategic significance and their actual contribution to Russia’s military operations at the time of the explosions.

Defence raises questions about state secrecy

Kuznietsov’s lawyers have also argued that his military status restricts his ability to discuss information that could be covered by Ukrainian state secrecy obligations.

According to the opening-day court reporting, the defence contends that these restrictions undermine his ability to challenge the prosecution’s case.

The proceedings also raise questions concerning the legality of his extradition from Italy and the precise offences for which his transfer was authorised.

These are separate from the underlying question of responsibility for the explosions. A procedural objection could affect the conduct of the trial without resolving the factual allegations.

Berlin faces an uncomfortable political dispute

The case has implications for relations between Germany and Ukraine, although criminal responsibility must be determined independently of diplomatic considerations.

Germany remains a major supplier of military and financial assistance to Kyiv. At the same time, German prosecutors are pursuing allegations that Ukrainian personnel damaged infrastructure in which German companies had invested heavily.

The pipelines themselves remain politically contentious. As EU Today previously examined, the owner of Nord Stream 2 has separately challenged the EU’s plans to eliminate Russian gas imports, demonstrating that the commercial and legal consequences of Europe’s former energy relationship with Moscow remain unresolved.

The Hamburg trial will not determine the legality of Russia’s invasion, nor will it establish Ukrainian government responsibility merely because a former officer stands accused.

It will examine the evidence against Kuznietsov and the circumstances in which the destruction of infrastructure connected to an aggressor state can constitute a criminal offence.

Further hearings are scheduled, with the evidentiary proceedings expected to begin on 27 October. The outcome will depend on whether prosecutors can establish the defendant’s alleged role and overcome the legal challenges raised by his defence.