There are a few other potential reasons for the invasion, and the US, EU, and whomever relies on Russian oil will continue buying it. There's no other option at the moment.

The US and Russia have been meddling in Ukraine over the last decade, and since the 90s, the US disregarded NATO expansion agreements. Perhaps, Russia is after Ukraine's agricultural lands and fed up with US foreign policy in the region. If Russia implanted miltary bases around the US border, I don't think the US would act kindly towards its neighbors.