I recall a story about oil from an embargoed country being pumped into empty wells in an unembargoed country, so that it could be pumped from there and safely traded on the market.

Does that ring a bell?

Buy low amd sell high. They will always do this for a country that needs something.

Interesting, it reminds me gas from Russia. I have heard that in Europe, gas from Russia is called gas from India. As people say in English you can't make this up.

Any time the state interferes in the market, there is an opportunity for the “black” market. Bans, taxes and regulation are usually the culprits. In the US cigarette smuggling and black marketing was a favorite. Trucks brought full truck loads of them in the Southeast, where tobacco was grown, and go to the high tax states and sell them at just under the taxed price. Lots of money in one truckload! Now they are trying to do it to oil. Lol

China buys most of Irans oil exports and pays a discount price. Ditto Russia.

China can defy the wests sanctions because the west dare not impose sanctions on China. China is now financing military aggression toward the west via proxies Russia and Iran and making a substantial profit at the same time. Sun Tzu would be proud.

Who said that all you need is free markets? Naive Libertarians...

No- the real world has always involved the nation and its power projection as significant factors in the wealth of the nation!