It turns out that the country behind the September 2022 bombing of the Nord Stream natural gas pipeline was almost certainly Ukraine—and US government officials have known it all along. The Washington Post reported this today based on intelligence leaks from the Discord Papers:
Details about the plan, which have not been previously reported, were collected by a European intelligence service and shared with the CIA in June 2022....The highly specific details, which include numbers of operatives and methods of attack, show that for nearly a year Western allies had a basis to suspect Kyiv in the sabotage.
....European officials in several countries have quietly suggested that Ukraine was behind the attack, but resisted publicly saying so over fears that blaming Kyiv could fracture the alliance against Russia. At gatherings of European and NATO policymakers, officials have settled into a rhythm as one senior European diplomat said recently, “Don’t talk about Nord Stream.”
The European intelligence made clear that the would-be attackers were not rogue operatives. All those involved reported directly to Gen. Valery Zaluzhny, the country’s highest-ranking military officer, who was put in charge so that Ukraine’s president, Volodymyr Zelensky, wouldn’t know about the operation, the intelligence report said.
Details of the Ukranian operation that were shared by the intelligence source are strikingly similar to evidence gathered by German law enforcement:
For instance, the Ukrainian individual that informed the European intelligence service in June said that six members of Ukraine’s special operations forces using false identities intended to rent a boat and, using a submersible vehicle, dive to the floor of the Baltic Sea then damage or destroy the pipeline and escape undetected. In addition to oxygen, the team planned to bring helium, which is recommended for especially deep dives.
German investigators now believe that six individuals using fake passports rented a sailing yacht in September, embarked from Germany and planted explosives that severed the pipelines, according to officials familiar with that investigation. They believe the operatives were skilled divers, given that the explosives were planted at a depth of about 240 feet, in the range that experts say helium would be helpful for maintaining mental focus.
Investigators...have linked Ukrainian individuals to the rental of the boat via an apparent front company in Poland. Investigators also suspect that at least one individual who serves in the Ukrainian military was involved in the sabotage operation.
Ukraine certainly makes more sense as a saboteur than either Russia, which had little reason to bomb its own pipeline, or the United States, which had already been mostly successful at persuading Germany to halt imports of Russian gas.
One interesting aspect of this is that it's yet another example of Ukraine's remarkable wartime proficiency. Just as Russia's performance in the war has been surprisingly poor, I don't think anyone expected Ukraine to be as capable and skilled on the battlefield as they have been. That the pipeline bombing, a complex and sophisticated undertaking, was conducted in secret and without a hitch, is further testimony to the Ukrainian military's fundamental competence.