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.
