If you look at present day Arabs, you will find many of them have ancestral connections with North Africans, Turks and Persians. Now, they are known as Arabs just because they are nationals of countries terms as Arab nations. So, the recognition of a person as an Arab is only due to his nationality in an Arab nation and not because of his ancesters.

Thus, a person is an Arab because of his nationality...a nation is not considered an Arabic nation because of its people's race.