When in Doubt , Study what Prophet Did:
Prophet Muhammad is an immigrant who migrated from the City of Makkah to Yathrib. After the Prophet’s migration, muslims called Yathrib as Madina or Madinatu An-Nabiy (or the City of Prophet Muhammad). At his first days in Madina, Muhammad declared the City as a city that welcoming immigrants from all over the world. The City’s residents comprised of the immigrants (muhajereen) and the natives of Yathrib, who helped the immigrants (ansar). They were united as one nation (ummah). All tribes regardless their religious affiliations would be included as the residents of the city of Madina. Prophet Muhammad approved the constitution of Madina that states, “Yathrib will be a safe place for the people of this constitution. A stranger (individual) who has been given protection (by anyone party to this constitution) will be treated as his host (who has given him protection) while (he is) doing no harm and is not committing any crime. Those given protection but indulging in anti-state activities will be liable to punishment.”
Muhammad and his companions built a welcoming city for immigrants and introduced a brand-new concept in the Arabian Peninsula. Immediately after the Prophet declared Madina as a welcoming city for all its residents, he broke the concept of Arabian tribalism that based on blood and changed it with a concept of a “nation”, or ummah. He ordered that the immigrants (muhajereen) and their helpers (ansar) would be united as brothers and sisters. Some helpers even shared their properties, such as houses and farms. A few immigrants such Abd Ar-Rahman bin Awf refused to get any shared property or farm. He only asked his “new brother”, Saad ibn Ar-Rabi, an assistance to show him the way to local market. At that time Saad is the richest man in the City. However, just in a few years, Abd Ar-Rahman achieved his “Madinah Dream” and became one of the wealthiest man in Madina too.
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PS: I respect people's personal opinions about who should get citizenship, it is your 100% right to agree or disagree.... my own personal views are based on Madina's concept of Immigration
The concept of Immigration is also very prominently applied in Western Countries