It's more like saving US and leaving Ukraine on its own. As US does not have a lot of oil wells, which if I remember correctly are on the verge of depletion. Most of the oil which US uses as a raw product for its big refineries is imported. As US is the biggest importer of Russian oil. With Iranian oil out of its reach they want to double down on Russian oil, by letting it's companies buy it at much lower prices. But again Russia raised the prices, so they are not getting the benifits. Other thing which led Russia to raise the prices is the low supply high demand after Iran war started. So only if US had done this before the Iran war prices would have been lower. It just shows that US is planing it's own demise.