The current German practice of stating only the name of the city, and not of the country, of one's birthplace, is not a tradition. It was instituted only recently - and not for all countries.
And stating only, e.g., "Mariupol" instead of "Mariupol, Ukraine" could by all means be construed as a political statement (namely one denying or at least casting doubt upon the validity of the Ukraine's existence as a sovereign nation).
Regards,
That says a lot about Germany then.
Interesting perspective about Ukraine too.