We NEED russian gas and oil. They need to sell it to us. So no neither side CAN sanction it for now. The best we can do is a huge, rapid expansion of import capacity from other countries.
We NEED russian gas and oil.
No, it's just a "want" (based on price point) like the other commenter said. Europe has other needs, like long-term security and stability. If these become threatened, it can easily (enough) find ways to offset the rise in prices caused by climbing down from Russia's teat.
They need to sell it to us.
On that point you are absolutely correct.