Russia wanted to cause panic and meltdown on EUs energy markets, but to no avail. Russia tried to sabotage gas supply by fiddling with turbines for months, but was in the end out of options, and EU gas prices were still too far from panic and collapse. Blowing up underwater gas pipes the same day that a gas pipe from Norway started to work - too good to be coincidence.
> Russia controls the pipeline, and could choose to turn it off
No, Russia cannot just turn off the gas without a force majeure cause (and even declaring the war to Ukraine, which will never be an option, is not a force majeure enough). Otherwise there are contractual obligations to fulfill, and enormous penalties in case of breaching contract.
penalties they could simply just ignore if they choose to. After all, they forced the sale in rubles, despite this not being part of the initial agreement of gas sales.
blowing it up seems just too much of shooting-self-in-the-foot for russia, unless russia can confidently lay the blame onto the west (particularly, the US) as the culprit.
And Russia immediately laid the blame onto the West, and never stopped. Maybe we are now looking at the part of that continuous effort.