Earlier quoted context omitted.
Russia's greatest leverage was Europe needing their gas, and eventually agreeing to stop supporting Ukraine in order to get the gas turned back on. Now if the pipelines are destroyed, no matter how cold and angry citizens in the EU get, EU leadership has no reason to give in to Russian since that now won't get the gas turned back on. If anything, this points to Ukraine or the US doing it.
Yes, Ukraine's famous Baltic sea combat divers.
(Just reading "green man" :D).