With reference to your question concerning ‘Abdu’l-Bahá’s reference to
“unity in the political realm”: this unity should be clearly distinguished
from the “unity of nations”. The first is a unity which politically
independent and sovereign states achieve among themselves; while the second is
one which is brought about between nations, the difference between a state and
a nation being that the former, as you know, is a political entity without
necessarily being homogeneous in race, whereas the second implies national as
well as political homogeneity.
(26 July 1936 to an individual believer) [62]