Maybe the question should be why dos the USA buy oil from Russia and sells oil to places China, India, Netherlands, S. Korea?
Why is it cheaper to buy oil from Russia, have it shipped from the Black Sea, across the Mediterranean, then the Atlantic Ocean than it is to send US oil from Beaumont, TX to Philadelphia or NY?
The answer is US regulations that require shipping between US ports to be done on US flagged and US manned ships (The Hatch Act). The US has only a few Oil Super Tankers and they all run from Valdez to US West coast ports. The costs to transport oil from Beaumont Tx to Philly for example are more on a small ship than to send a super tanker from Rostov on Don on the Black Sea. It's completely stupid.
The other issue I have is that the USA meddled in Ukraine, helped overthrow the elected government in a real armed insurrection, installed a BS government, changed the Constitution and are upset that the ethnically Russian parts of Ukraine voted to leave. We said that it was "illegal'! Then we trained and armed the NAZIs in Ukraine who have terrorized and killed these ethnic Russians for the past 8 years.
But somehow it is Putin's fault for trying to put an end to that. And to try to get the USA to abide by it's promises that Ukraine would never be allowed to join NATO. But the new constitution the US helped to get written requires the Ukrainian government to seek NATO and EU membership. That sounds like the USA going back on it's assurances made when Russia allowed East and West Germany to reunite. part of that deal was that NATO would not expand eastward and no offensive military equipment would be placed to the east.
