As it is said by Prophet Muhammad (Sallallahu Alaihi wa Sallam) no Arab has priority over a non-Arab, non-Arab on Arab and black over a white and so on. Except for the person who is Muttaqi (afraid from Allah) but nowadays Arab countries only call Arab countries as Ikhwan (brothers) and have their separate organizations like Arab League and so on. Why is it so?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Limiting brotherhood to Arabs is an extremism and a pre-Islamic act. In fact, the Prophet (Sallallahu Alaihi wa Sallam) fought this and made it clear that there is no superiority of an Arab over a non-Arab or a non-Arab over an Arab as there is no merit of a black over a white or a white over a black except by piety.
So, all peoples are equal as Allah Says (interpretation of meaning): {O mankind! We have created you from a male and a female, and made you into nations and tribes, that you may know one another. Verily, the most honourable of you with Allâh is that (believer) who has At-Taqwa (piety) [i.e. one of the Muttaqûn. …} [49: 13].
The Muslim must call people to unite considering the Holy Qur'an and the Sunnah their only judge and the tie by which they are all linked together. In fact, the relation that brings Muslims together is belief not country or colour, … etc.
Allah Says (interpretation of meaning): {The believers are nothing else than brothers (in Islâmic religion). ….} [49: 10].
The Prophet (Sallallahu Alaihi wa Sallam) also said: "A believer to another believer is like a building whose different parts enforce each other" . The Prophet then clasped his hands with the fingers interlaced (while saying that). [Reported by Imams al-Bukhari and Muslim ].
So, all Muslims should fight against such confessional feud and sectarism. Similarly, our non-Arab brothers should not think that all Arab Muslims are calling for Arabism. In fact, those who call for such sectarism are a group who do not know the reality of Islam.
Indeed, they disguised themselves from Islam, although they call themselves Muslims, they have given a distorted picture of Islam which caused some people to disregard Islam.
Allah knows best.