What is the religious ruling on a young man who cancels his promises of marriage and residence in his fiancée's country after the death of his brother, and insists on residing in his own country, justifying this by pleasing his mother and his Lord, knowing that his fiancée has refused other marriage opportunities because of him, and she insists on residing in her country for practical reasons, and he is capable of finding solutions that satisfy all parties?

If the marriage has not yet taken place, and what was issued by the young man was merely a promise, then, according to most jurists, it is not obligatory to fulfill it, unless the one who was promised incurred a cost, in which case it becomes obligatory to fulfill it. If what he issued was a condition, then the preponderant opinion is that it is obligatory to fulfill it. If you fear that this matter will be a cause for future disagreement, then it is permissible to annul the engagement, while severing all ties with him, and to ask Allah to replace him with someone better for you, as Allah Almighty says: "But 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."