Nationalism
Islam forbids nationalism of any kind and in his last speech the Prophet SAW stressed this point.
"An Arab has no superiority over a non-Arab, nor does a non-Arab have any superiority over an Arab; a white has no superiority over a black, nor does a black have any superiority over a white; [none have superiority over another] except by piety and good action. Learn that every Muslim is a brother to every Muslim and that the Muslims constitute one brotherhood."
There is no Arab nationalism, Turkish Nationalism, Iranian Nationalism or Pakistani Nationalism in Islam.
Only he who fears Allah i.e. Mutaqqi is given preference.
The Caliphs asked the Arabs soldiers to intermarry among the local people after the conquests which resulted in cementing the relations between different peoples in Africa, Arabia, Turkey, Central Asia and India.
The enemies of Islam use their secret agents to make the tribes and sects fight with each other. Lawrence of Arabia is a case in point who raised the standard of Arab Nationalism.
Even now, the tribes in Afghanistan ie. Pashtuns, Tajiks, Uzbeks and Shias are being made to fight with each other. The sects in Pakistan and Iraq are fighting with each other. the Arabs and Berbers are fighting in Algeria. They have created a similar situation in Sudan among nomadic and agricultural people.
All of these nationalism are wrong and not allowed in Islam.
The Prophet SAW said
"O People, no prophet or apostle will come after me, and no new faith will be born. Reason well, therefore, O people, and understand words which I convey to you. I leave behind me two things, the Quran and my example, the Sunnah, and if you follow these you will never go astray."