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.