Russia's Desperation Is Frightening! Ukraine Daily Update! 29 September 2022

Your analysis is faulty, The US has all the motivation to distrupt the flow of gas to Europe.

1. The US sells natural gas to Europe, and so the Nordstream pipeline is a competitor.
2. Russia does not have a motivation, as they can turn of the spigot at the source. They have turned it off, but don't want to destroy their future profits after the war. Further, by destroying the pipeline it will take a long time to fix, or may need to be totally rebuilt. No, it is not in Russia's interest to destroy their pipeline.
3. Sure, Russia lies. But, have you been tracking any of the lies of the US government? Vaxx being safe and effective, Russia collusion, cleanist election ever, policeman killed on J6, armed insurrection, weaponization of the justice system, "inflation reduction act." Politicians lie, and that includes US politicians, and this is something they would lie about.
4. Large explosions recorded by Swedish seismologists. Once again, Russia could simply and inexpensively turn off the gas flow, or dissasemble the pipeline on land. Underwater explosions at depth are expensive and take the right equipment. The US has the equipment, so they have the means of doing it.
5. US politicians threatening to destroy the pipeline if Ukraine was invaded. Biden was one of the people saying it, so it could very well come from the top.
6. Systematic intentional sabotage of food processing plants and refineries by eco-terrorists that are probably in the administration. This has been going on all summer in the United States. It is clear they would do it overseas to force people away from burning carbon fuels, while insisting on wind and solar and forbidding nuclear. It fits the pattern.

There is a 95% chance that it was the US, 4% chance it was another NATO country, and a 1% chance it was some kind of mechanical failure with a large implosion or a rouge Russian sub captain who disliked Putin. There is no chance it was the Russian government.