No use to go to US reg. To my knowledge they receive the same treatment returning to the US from a foreign place. Still very curious: how FAR 135 ops could operate in this enviroment?
(Recently completed a trip from LCPH to LOWW via Athens/Makedonia/Sofia/Belgrade/Budapest FIR's. The only requirement was a FPL filed in time. Through all these "difficult" countries. Remarkable! I just hope boss won't plan a X-mas dinner in The Big Apple.)