Sasha's not Ukrainian, he was born in Russia and moved to Australia when he was 2. edit: just checked Wikipedia, actually he was born in the Soviet Union in what is now Belarus, so we were both wrong. I'm sure I've heard him refer to himself as Russian though. Actually, so did Val and Maks before the war. I remember a photo with Val, Maks, Gleb, Sasha and Artem or Pasha captioned something like 'Russian bros'. Sad times indeed.
I'm sure I read somewhere that Ukraine doesn't allow its citizens to hold dual citizenships, so Nikita can't have an Italian one unless he gave up his Ukrainian one.
Surely his diabetes would exempt him though? Even in a non-combat role, surely it would be more trouble than it would be worth for them to have someone around who could drop dead if insulin supplies are delayed or power outages prevent it from being stored correctly or whatever?