This is a fascinating mystery. There's at least 4 parties that you can make arguments for/against:
Russia
For: Plunge Europe into an energy crisis to force concessions in Ukraine
Against: It looks a lot like a glass cannon to me. Meaning, Europe will now change their behavior to remove dependence on Russian energy.
USA
For: They've been against the Nords from the beginning and could pull something like this off
Against: Big escalation, huge potential blow back from Europe, and economic fallout is bad for the midterm elections
Ukraine
For: Removes a large source of Russian leverage over Europe
Against: Doesn't seem like they could pull it off and it risks the support from Europe they do have
Random European Country
For: Lots of them don't like the dependence on Russian energy and many of them have the means
Against: Huge escalation with Russia and risks discord amongst the EU
Russia
For: Plunge Europe into an energy crisis to force concessions in Ukraine
Against: It looks a lot like a glass cannon to me. Meaning, Europe will now change their behavior to remove dependence on Russian energy.
USA
For: They've been against the Nords from the beginning and could pull something like this off
Against: Big escalation, huge potential blow back from Europe, and economic fallout is bad for the midterm elections
Ukraine
For: Removes a large source of Russian leverage over Europe
Against: Doesn't seem like they could pull it off and it risks the support from Europe they do have
Random European Country
For: Lots of them don't like the dependence on Russian energy and many of them have the means
Against: Huge escalation with Russia and risks discord amongst the EU