Intelligence and diplomatic officials in the United States and Europe suspect that pro-Ukraine saboteurs may be responsible for explosions in September that severely damaged the Nord Stream natural gas pipelines, an attack that could erode support for Ukraine among the Western nations that have come to its defense against Russia.
As the weeks wore on, no evidence to support that claim materialized, according to multiple officials familiar with ongoing investigations and intelligence reviews. But officials in several countries said Ukraine could have been motivated to attack the pipelines to stiffen Western resolve in the face of Russian aggression, and their suspicions soon turned to Kyiv.
There is still no forensic evidence from the blast site that concretely ties the sabotage to any country, officials have said. Intelligence agencies in the United States and Europe have not intercepted communications of Russian or Ukrainian officials taking credit for the attack or suggesting that they’re trying to cover up their governments’ involvement.
But recently, more information shared with officials in Washington and Europe suggests that a pro-Ukraine group, perhaps operating without Kyiv’s direct knowledge, may have carried out the attack, according to officials familiar with the matter who spoke on the condition of anonymity to discuss sensitive information with significant diplomatic implications.
A senior Western security official said governments investigating the bombings uncovered evidence that pro-Ukraine individuals or entities discussed the possibility of carrying out an attack on the Nord Stream pipelines before the explosions. The official referred to “signals” that such an operation was discussed or considered. The official emphasized that these communications were only discovered after the attack as Western spy agencies began scouring intelligence data for possible clues.
The information was offset by other intelligence suggesting the possibility that Russia was responsible. Separate intelligence, for example, showed that Russian naval vessels were detected at or near the locations of the attack in the weeks leading up to the explosions.
The official considered it unlikely that Ukrainian President Volodymyr Zelensky or members of his inner circle would have sanctioned such an operation, noting that they have been careful to avoid jeopardizing the Western support that has been a lifeline for Kyiv.
U.S. officials have regarded the recent intelligence pointing to Ukrainian saboteurs cautiously.
“My understanding is that we don’t find this conclusive,” a senior Biden administration official said.
In Washington and Europe, some said they were worried a Ukrainian-linked attack would weaken NATO support for Ukraine, particularly in Germany, where many citizens remain sympathetic to Russia and skeptical about arming Kyiv. The pipeline attacks have heightened anxieties about the vulnerability of the energy sector across the continent.
“This was an attack against critical infrastructure for Europe, but there are ongoing investigations and inquiries, and it wouldn’t be right to speculate who is behind that until the investigations and inquiries have been concluded,” NATO Secretary General Jens Stoltenberg said at a news conference in Stockholm on Tuesday.
The Nord Stream bombing provoked a significant and continuing NATO response. “We have doubled our military presence in the North Sea and the Baltic Sea,” Stoltenberg said. “We have also increased the cooperation between NATO countries to exchange information and to strengthen preparedness to better stop further such attacks in the future.”
Spurred by the attack, the alliance is also working on a plan to improve underwater security at an annual summit this summer.
The mystery over who blew up the pipelines has persisted in part because it is not clear who had the technical capabilities to pull off the operation.
Some officials continue to say only a nation-state would have the requisite expertise and tools to carry out a complex underwater sabotage operation. But others counter that given the relatively shallow depth of the damaged pipelines — approximately 80 yards at the site of one explosion — a number of different actors could theoretically have been behind the attack, possibly with the use of submersible drones, divers or surface ships. The list of suspects isn’t limited only to countries that possess crewed submarines or deep-sea demolitions expertise, these officials have said.
Speaking alongside Stoltenberg, Swedish Prime Minister Ulf Kristersson cited an ongoing investigation when he declined to comment on an article in the New York Times, which first reported the recent intelligence suggesting a pro-Ukraine group had carried out the attack.
The Ukrainian government denied any involvement in the sabotage.
“Ukraine absolutely did not participate in the attack on Nord Stream 2,” said Mykhailo Podolyak, a top adviser to Zelensky, questioning why his country would conduct an operation that “destabilizes the region and will divert attention from the war, which is categorically not beneficial to us.”
Podolyak said that in September, when the Nord Stream explosions occurred, Ukraine was focused on a counteroffensive in the Kharkiv region. The adviser said an attack on the pipelines would have distracted from the war and Russia’s attacks on Ukraine, and given Moscow a talking point to try to pin sabotage attacks on the West.
The Kremlin has blamed, at various points, Ukraine, Britain and the United States for the explosions.
White House spokesperson John Kirby didn’t comment directly on who might be to blame for the attack, telling reporters, “We need to let these investigations conclude, and only then should we be looking at what follow-on actions might or may not be appropriate.”
Podolyak argued that Russia not only has the capability to commit the pipeline attacks and obscure responsibility by blaming unidentified pro-Ukraine groups, but also a motive to drive a wedge between Kyiv and its Western backers.
Investigators have also been mindful of the possibility that Russia or another government could have planted evidence to sow confusion.
But Ukraine has been linked to clandestine attacks involving unconventional methods, such as bombings and assassinations, that appear designed for political effect more than battlefield gains.
Western officials say Ukrainian actors are responsible for a car explosion in August that killed the daughter of Alexander Dugin, a Russian nationalist and ideological ally of President Vladimir Putin. Some officials said that Dugin was the intended target and that Kyiv was admonished over the attack by its Western allies.
Drone strikes attributed to Ukraine have hit targets in Russia, including air bases near Moscow.
Ukraine’s special services were behind a spectacular explosion on Crimea’s Kerch Strait Bridge in October, a stunning blow to a symbol of Putin’s ambitions to control Ukraine.
German news reports on Tuesday raised more questions about potential Ukrainian links to the Nord Stream attack. German authorities reportedly had made a “breakthrough” in their investigation, according to a joint investigation by multiple German media outlets, and had identified a small team of saboteurs using a yacht rented from a company in Poland that was “apparently owned by two Ukrainians.”
Germany’s Federal Prosecutors Office didn’t respond directly to the press reports, but confirmed in a statement that from Jan. 18 to 20 of this year, “the federal prosecutor had a ship searched in connection with a suspicious ship rental. There is a suspicion that the ship in question could have been used to transport explosive devices that detonated on” the pipelines, the statement said.
“The identity of the perpetrators and their motives are the subject of ongoing investigations,” the prosecutor’s office continued. “Reliable statements on this, especially on the question of state control, cannot be made at this time.”
David L. Stern in Kyiv, John Hudson and Karen DeYoung in Washington, and Kate Brady in Berlin contributed to this report.