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.
It is the right of a wife upon her husband that he should not be away from her for more than six months. Some scholars say four months. This is the rule given by the Commander of the faithful, Omar , (Radiya Allahu Anhu) after he knew that the woman can only endure waiting for this period and not more. Based on this, you should not stay away from your wife for this long period without her permission and consent. If she is not pleased with your staying away from her, you should go to her or bring her to stay with you. As for attaining foreign citizenship, if it is for the purpose of living in the land of infidels or migrating there, unnecessarily, that is unlawful. This is because there are dangers for members of your family, your own self and your offspring in living among the infidels in their countries. If your intention of getting citizenship is not for the purpose of living with them but only in order to avoid troubles that a man is normally exposed to from unjust people, there is no objection to that - Insha Allah - because this is in order to avert harm and injustice. In view of the above, you should not stay away from your wife for more than six months except with her permission. There is also no objection in attaining foreign nationality in order to achieve lawful benefits or avert an impending harm. But it is unlawful to live in the land of infidels unnecessarily. We therefore, advice you to fear Allah and to seek His Guidance through Istikharah in all that you do. Istikharah means observing two Rak'ahs and reading the Istikharah invocation as reported by A-Bukhari and Muslim . Allah knows best.