Looking to see how many financial Institution maintain clients that are in comprehensively sanctioned countries e.g. Iran, Syria, Cuba, Ukraine (Crimea). Would also like to hear the "risks" of doing" so (e.g. secondary sanctions, human rights, inadvertent/dormant connection with prohibited banks and/or industries) Thank you in advance.

My bank has a policy prohibiting such clients (though there is an exceptions process, if justified).  This is because most of those countries are also sanctioned under our domestic autonomous regimes, but we also want to help our correspondent banks keep within their risk appetites and need to keep our USD clearers.  Given the risks, my question would be, under what circumstances would we want to do such business?