Even if Norway had something to do with, I'm sure they weren't acting alone. The US had consistently been strongly opposed to the pipeline since the start (long before the Russian invasion of Ukraine). And besides, Biden literally threatened to "end it" and said that "there will no longer be a Nord Stream 2" in the months before it was attacked...
What's throw me off of the 'the Cia did it' is that the authors left clues, and the operation wasn't that tight.
It was tight enough, sure. BTW that's way there is no way Russia did it, their opsec is shit and they get caught by osint all the time. But not as clean as what some alleged Cia operations are (like what happened to French assets in Libya, Clinton's e-mail hinted it was an op, yet without the leak nobody's would even think USA was involved). This was sloppier imho.
It still can be US work, but I would be surprised if it were a federal agency.
After Biden literally saying they'd take care of it, all the NATO aligned press started to imply that it was Putin's doing, to blame it on the west.
Anyone suggesting that Putin didn't need to do that (he could just not send gas) is considered a conspiracy theorist at the same level of a flat-earther.