The exact reasons aren't entirely clear, originally they hated NS because it allowed Europe to ignore Ukraine in the gas trade which left them more exposed. By the time of the full scale war I would bet the reason was more "fuck Russia" than anything more carefully reasoned.
Nobody remembers anymore that Pres. Biden himself said, “If Russia invades ... there will be no longer a Nord Stream 2. We will bring an end to it.” [°] Nor that the very next day, a EU parliament member, and now Polish foreign minister Radosław Sikorski thanked the US for the sabotage [^]. Nor that the same day, a competing natural gas pipeline has opened, the Baltic Pipe [_].
None of this matters, because "Ukrainians bombed it". Because WaPo and WSJ said so. In a waterway that is heavily controlled by all kinds of NATO vessels. Where NATO had an exercise 3 months before that, called BALTOPS. Come on.
[°] https://www.youtube.com/watch?v=OS4O8rGRLf8
[^] https://archive.ph/20220927190022/https://twitter.com/radeks...
"Nord Stream sabotage: Berlin issues arrest warrant for Ukrainian man"
https://www.lemonde.fr/en/international/article/2024/08/14/n...
https://www.reuters.com/world/europe/what-is-known-about-nor...