They clearly meant via the use of either sanctions or other political / legal means, which is exactly what happened because Nord Stream 2 never opened.
I think that's far from clear, verging on very naive. They spent the existence of both pipelines trying doing exactly what you described but could not stop them. Clearly they meant bomb it. And, no, I'm not saying they did. As my other comment indicates Russiais just as if not more likelythe culprit.
It is a tweet posted in February 7th by ABC News:
Pres. Biden: "If Russia invades...then there will be no longer a Nord Stream 2. We will bring an end to it."
Reporter: "But how will you do that, exactly, since...the project is in Germany's control?"
Biden: "I promise you, we will be able to do that."