You may recall that Trump warned them not to rely on an enemy for their energy supply and they laughed at him. Russia presently supplies about 55% of Germany's Nat Gas Supplies. LNG shipments from the US are at capacity and it will take years for port infrastructure and new ships to increase shipments to Europe to even begin to supply them with their needs.
Link: https://www.zerohedge.com/energy/gazprom-halts-gas-shipments-europe-critical-pipeline