Or, alternatively, it's a strategic benefit to Russia to plant the idea of US treachery in the minds of the Germans.
I have no opinion and doubt we'll ever know what actually happened. Definitely sabotage, though.
(1) An understanding of the facts of how successful the EU has been at diversifying away from Russian gas and whether NS2's natural demise was all but an inevitability.
(2) How much the repairs will cost.
If the repair costs are low, it's probably Russia, because of the propaganda value.
If NS2's demise was highly likely, again probably Russia because they're leveraging a sunk cost to their benefit which is just smart.
But so many people are making confident assumptions about (1) and (2) in this thread. If you don't know the answer to those questions, stop forming strong opinions!
My opinion was solely that quote is weak evidence.
I don't think that Biden was threatening to blow up the pipeline, but what you've given is a somewhat sugar-coated version of the American approach towards Germany and Nord Stream 2.
Long before the Russian invasion of the Ukraine, the US began sanctioning German companies involved in NS2. The American approach to NS2 has been rather blunt, given that Germany is a close ally that usually toes the line, even to its own detriment.
At the time, I read Biden's statement as a promise that the US would sharpen sanctions on German companies involved in the project if the Germans did not willingly exit the project themselves.
While I don't doubt the factuality of this, I didn't get that from this specific briefing (given that it was with Scholz, who expressed unity with the US's position).
In other words: unless Scholz is saying one thing and doing another, there would be no specific need to threaten German companies with additional US sanctions; Germany's government would (and eventually did) take action on its own.
(I don't mean to sugar-coat the US's foreign policy, which can be succinctly and accurately described as "uniformly nasty until we get what we want.")
I wouldn't read too much into Scholz' expression of unity with the US position. The German government almost never criticizes the US government (with some very rare exceptions, such as in 2003, in the lead-up to the Iraq War). If you ever want to hear German government spokespeople tying themselves into knots, just listen to them try to explain their position on the US prosecution of Assange,[0] or on whether Germany would give asylum to Snowden.[1]
The more sensible interpretation is that Biden was threatening to fully support Germany's plans to become energy independent. And that's, so far, what we've seen the US commit to.