Russia required all male Russian immigrants in USA and Canada to register
at a Russian Consulate during WWI. Not sure if they did the same during
the Russo-Japanese War. These can be located through the American Society
of Germans >from Russia Historical Society. Under Russian law you were
elligible for Russian military service if a grandparent had been a Russian
citizen. This was the same rule for eligibility to vote in some recent
Russian elections. Not sure if it is still the law.
Steven C. Perkins