I read Breaking Rockefeller by Peter Doran recently. John D. Rockefeller was perhaps the richest person ever, adjusting for inflation. Rockefeller was from Ohio and got into the oil business in the late 1800s. Recall that nearby Pennsylvania was the capital of the oil world at that time. Rockefeller gradually monopolized the industry.
Doran called Rockefeller’s tactic “cut and crush”. Rockefeller either drove the competition out of business or forced a sale to him. The Cut and Crush tactic worked as follows: Rockefeller cut prices on oil such that buying from his company, Standard Oil, was compelling wherever the competition did business. Oil extraction and refining is capital intensive. Standard Oil had strong capital resources and could afford to lose money almost indefinitely. The competition, on the other hand, usually operated with much less substance. The competition could not afford to lose money, and either went out of business, or agreed to sell to Standard Oil.
My point in mentioning this tactic is that maybe the Western countries supporting Ukraine should reverse themselves? Instead of banning oil purchases, we ought to start buying oil products again from Russia. Prices should fall, and while Russia will still get revenue, it will make oil less profitable.