Any Southern European Mediterranean, Slavic, or Baltic individual who is a White nationalist is a useful idiot no different from good goys that want to die for Israel. You are a cuckold who support people who think you are inferior and would never include you in their in-group.
Basically, they see you as useful idiots, and will pretend to be the same race as you in polite company, but deep down they think they are superior and that you are mongrelized bastards. You'd have to be masochistic to have anything to do with that. Ask any 1488er what they actually think of people from Southern Italy, Bulgaria, Russia, or Greece, all that "pan European pro-white unity" will vanish and the truth comes out: they think you are subhuman and they have all sorts of fake Nordicist history and HBDer talking points about "muh Hajnal line" and how Eastern Europe was uncivilized and required German overlords to create a functioning state or how Meds are mongrels in order to justify the racial superiority of Germanics.
If you still want to be a "White nationalist" or a "pro-white" after that then be my guest. In my view, you should have a little self-respect instead of cucking to people that hate you. Even Oswald Mosley, the most pan-European Fascist of the time by far, did NOT include the Slavic people as part of the European race and "our people". They were considered asiatic savages.