AsalamuAlaikum,
I would say no brother:
Allah says:
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 Allah is that (believer) who has At-Taqwa [i.e. one of the Muttaqun (pious). Verily, Allah is All-Knowing, All-Aware. [Quran 49:13]
The Prophet (peace and blessings of Allaah be upon him) said:
“O you who believe, verily your Lord is One, and your father [Adam] is one. There is no superiority of an Arab over a non-Arab or of a non-Arab over an Arab, or of a white man over a black man or of a black man over a white man, except in terms of taqwa (piety). Have I conveyed (the message)?” They said: “The Messenger of Allaah (peace and blessings of Allaah be upon him) has conveyed (the message).”
[Narrated by Ahmad, 5/411, Bayhaqi and Bazzaar; classed as saheeh by al-Albaani in Ghaayat al-Maraam, 313; it was also narrated from Shaykh al-Islam Ibn Taymiyah that its isnaad is saheeh, in al-Iqtidaa’, 69]
The Prophet (peace and blessings of Allaah be upon him) said:
“Those who boast about their forefathers should desist or they will be less significant before Allaah than the beetle that rolls up the dung with its nose. Allaah has taken away from you the arrogance of Jaahiliyyah and its pride in forefathers, so a person is either a pious believer or a doomed evildoer. All the people are the children of Adam and Adam was created from dust.”
[Narrated by al-Tirmidhi, 3890; classed as hasan by al-Albaani in Saheeh Sunan al-Tirmidhi, no. 3100; and in Ghaayat al-Maraam, 312, it was said that al-Tirmidhi and Shaykh al-Islam Ibn Taymiyah classed it as saheeh]
When one sits and reads through the Quran and the Sunnah we see countless examples of sticking together as Muslims. As one Ummah. One Community.
Which is against nationalism or splitting up into different countries.