Is it permissible for parents to refuse to marry their daughter to a righteous, religious, and suitable young man merely because of a difference in nationality, even though they are aware of their daughter's strong desire for this marriage?

The questioner should make abundant supplication, as Allah has commanded it and promised to answer. The guardian is not permitted to reject a suitor who adheres to Islamic law, and the suitor being from another country is not a religious impediment. If the parents do not agree, the matter can be raised before the Sharia court for the judge to solemnize her marriage. If the questioner chooses to honor her parents and forgo marriage to someone they do not desire, Allah may grant her someone better. Therefore, she should entrust the matter to Allah the Almighty, for He says: "And perhaps you hate a thing and it is good for you; and perhaps you love a thing and it is bad for you. And Allah knows, while you know not." The father disowning his daughter does not negate her lineage; this is something he cannot deny, and there is a severe warning for those who disavow their child.