If you know the way the US often imposes sanctions, it entails prohibition of both buying and selling from sanctioned parties. I work on many sales and procurem

If you know the way the US often imposes sanctions, it entails prohibition of both buying and selling from sanctioned parties. I work on many sales and procurement systems in the US that call services such as Amber Road or Descartes that scan the government provided lists of sanctioned parties before a PO or SO can be placed, delivered, or billed. Russia not selling its gas to an adversary is a simple sanction of this kind.