"Gigantic risk for the US and would eventually be found out" This is predicated on the assumption that the US intelligence community would leak it anytime soon

"Gigantic risk for the US and would eventually be found out" This is predicated on the assumption that the US intelligence community would leak it anytime soon (within the current presidency). That seems like a very poor assumption. If it's never proven they did it, there's no real risk because people who don't want to believe will invent other explanations. You see it happening in this thread already - it's not the country that literally said they had ways to ensure NS2 would never activate, no, it must be the country that built it. 4D chess! "These pipelines weren't deliving gas anyway" No, but that could have been changed very quickly if wanted. All three pipelines were pressurized. NS2 was all new equipment, ready and waiting to go. "The US would prefer energy markets to be stable and not have sky-high prices" The US has consistently and strongly opposed European dependence on Russian natgas under (at least) two different presidents. Neither of them seemed to care much about the question of what to replace it with. At any rate such an operation would be signed off by Biden and highly classified, so it's not like "the US" would have an opinion on what matters more anyway, just a senile old man.