You got proof that the US blew up the pipeline? And by the time the pipeline was blown up, it was already not being used.
As for what Putin wants, he has made it very clear that he thinks certain portions of the old Russian empire like the Baltics and Poland, should be restored to Russia. He actually has troops in Moldova.
And you may think it is inconsequential that Finland, a country that had always tried to remain neutral between Russia and NATO, joined NATO after the Russian invasion of Ukraine. That goes for Sweden too. And Finnish intelligence has always kept a very close eye on what Russia is up to.