Ref Ukraine

[Tarrel]

You know, one of the most threatening and scary things Russia could do generally in the world, would be to declare "unilateral self-sufficiency":

"We're not going to sell you our oil - we'll keep it for ourselves thanks"
Ditto gas
Ditto grain
Ditto coal, etc, etc.

Then pull the drawbridge up and watch the world go to ratsh*t from their rocking-chair on the porch!

There is a peak-oil principle known as the "Export Land Model", which examines how global oil supplies will pan out during the downslope after the peak. It basically says that countries that currently export oil (and gas) will start to retain more of it for themselves, and the international free trade in such commodities will gum up. The result is that the decline of supply will be a bit of a "postcode lottery", depending on whether you live in a "have" or "have not" country. The potential for conflict also goes up as desperate countries go in and take what they need.

Apologies for going slightly off topic.