Actually there is a very good wikipedia page "United States sanctions against Iran" https://en.wikipedia.org/wiki/United_States_sanctions_agains... about this, if you want more info.
I trust Oracles lawyers to know the law better than a wikipedia page.
http://www.oracle.com/us/products/export/export-regulations-...
Nationality of individuals is primarily relevant for deemed-export under ITAR/EAR; not the OFAC sanctions on Iran.
Quoted from GitHub CEO Nat Friedman on Twitter:
> The restrictions are based on place of residence and location, not on nationality or heritage. If someone was flagged in error, they can fill out a form to get the restrictions lifted on their account within hours.
Wording like this appears on the treasury documents, Google cloud and Oracles official documentation on sanctions.
I'll just link the Oracle one because ironically the one that google uses is really difficult to find:
http://www.oracle.com/us/products/export/export-regulations-...