We don't know if the German government knows who did this. So I don't think we can draw any conclusions from the lack of action here, we simply do not have enough information.
What are you talking about? Western companies literally own half of NS2.
>no gas ever has flown through it and none would have almost certainly even if it were still fully intact (one strand is undamaged)
I wonder if intentionally delayed certification of the pipeline by Germany has anything to do with "no gas ever has flown". The point is: NS1 + NS2 was a constant temptation for Germany and blowing it has removed the "wrong" incentive.
By the way, nobody wanted NS2 by the time it was technologocally ready. Funny enough, if Trump wouldn't have been president a deal for CNG anf LNG would have been had a lot easier and earlier.
I call BS. Not only have they invested a significant amount of money into it, they also sell gas to Europe through Ukraine even today. I think they would like to have working pipelines which do not cross any intermediate states, even in offline state.