50 USC 1702(a)(1)(A) explicitly authorizes the President (under the appropriate circumstances) to "prohibit", among other things, any transactions in foreign ex

50 USC 1702(a)(1)(A) explicitly authorizes the President (under the appropriate circumstances) to "prohibit", among other things, any transactions in foreign exchange with a particular country. If a US person is doing business in said country (necessarily using that countries' banking system) it would be a violation. The conditions that would authorize the imposition of penalties have not been triggered. Yet.