What other effective means? The USA already imposed direct sanctions on Germany to try and stop Nord Stream 2 from being built, a very hostile move that supposedly resulted in 'incomprehension' in the German Foreign Office. It didn't work.
Nowhere near (re-)opening: we don't really know this. The Greens are loud and extreme (saying they don't care how much pain Germans suffer) but we don't know what's going on behind the scenes. USA spies on all the European countries all the time and obviously Russia too, so they presumably have better insight into the true state of German decision making than we do here on HN. It's possible they got some intel that was interpreted as meaning that they were getting close to re-opening NS1 or open NS2 and decided to act before that was possible.
There's also some evidence that this may have been planned for a long time, in which case it would again make no sense to be Russia.
Way back in 2015 an underwater robot laden with explosives was found next to the NS pipelines by Swedish special forces:
https://www.pipeline-journal.net/news/explosive-laden-drone-...
Who was opposed to NS in 2015? Only the USA. But it gets worse :( In August the US Navy entered the area right next to where the explosions happened and then switched off their identification transponders:
https://www.ndr.de/nachrichten/schleswig-holstein/US-Navy-ze...
(auto translation) "A total of 4,000 US soldiers, helicopter pilots, marines, doctors and strategists are on their way east. At around 6 a.m. on Wednesday morning, the association had already passed the Danish island of Bornholm, when the Americans switched off their automatic ship identification systems (AIS) and could no longer be located without further ado."
It seems to me like this is going to immediately turn into another COVID lab leak problem where the media and governments go into overdrive to bury the most obvious and straightforward explanation. Give it 24 hours and linking to the articles I just showed you will be banned on Twitter/Facebook and anyone saying "the USA is the most obvious suspect" will be banned from YouTube. Then maybe in three years suddenly it'll become acceptable to talk about.