There is a VERY clear difference between ethnicity and nationality. Regardless of oxymoronic semantics, nationality is being of legally being of that countries national, it DOES not mean a synonym for ethnicity. You mean if one is a citizen of a country, you arent of that nations nationality just because you arent of that ethnicity? What are you called then if you are born there and live there? They arent to be called of that nationality because of differing ethnicity?
There is a reason why two words are used for very different uses. Get that throw your head, people of the same nationality can be from half of dozens of ethnicities. For example Iraqi's are all Iraqi nationals despite the several different ethnic groups and such. Nationality does NOT have the very narrow specific meaning of ethnicity.