There are plenty of sanctions that could've been imposed against Russian aggression without direct impact on Europe.
The sanctions were passed specifically in order to stop this pipeline. The reason Russia wants this pipeline is in order to bypass Ukraine, so that they can cut off gas supply to Ukraine without pissing off the rest of Europe.
This is a gift to Putin, and makes Russia stronger and NATO weaker.
Trump stood up to Putin and Merkel, and Biden caved to them. I don't think it's because Putin "has something on him", but we all know that if Trump had done anything similar you wouldn't be making excuses for him...