The biggest "if" of the Russian war on Ukraine is, and has always been, if Europe and the rest of the free world have the will to defend themselves, their interests, and their values. Ukraine does.
If the EU wants to be taken seriously, it has to hurt Russia in a material way. Half of Russia's seaborne oil leaves via the Baltic and half of those shipments are on the shadow fleet. Shut that down. That will plunge Russia into deep financial crisis, which is what it deserves.