Diplomacy, sanctions, sabotage, military interventions.. They're all just a spectrum. Of course it shouldn't be understood as proof the US did it but to ignore that they had a strong geopolitical interest in having NS gone is naive. Would the white house approve it, given that it's partly allied civilian infrastructure, if the risk of getting caught is deemed low? I don't think that's impossible. They spied on those same allies and their top government officals, for instance.

This is a clip of Biden speaking, what does it matter what channel it's posted on?

The only believable explanation for the attack on Nordstream I have heard so far is this threat. That is, the supposed idea is to make Europe wonder if any other pipelines could be targets.