Is it permissible to marry a Christian woman who has expressed her willingness to embrace Islam for the sake of marriage, with the intention of bringing her into Islam, knowing that there is no affection towards her, and that the potential husband wishes to return to his country and marry another woman later?

It is better for a Muslim not to marry a Kitabiyyah (a woman from the People of the Book), but rather to marry a Muslim woman who is religious, especially in current times due to the numerous harms and risks associated with marrying Kitabiyyat. Nevertheless, marriage to a chaste Kitabiyyah is permissible, and even desirable if there is hope of her embracing Islam. If the apparent situation of the woman indicates that she will embrace Islam out of a desire for marriage, there is no impediment to assisting her in becoming Muslim, for a disbeliever might embrace Islam for a worldly purpose and then perfect their Islam. So, if she is chaste and there is hope for her Islam, there is no objection to marrying her. If you marry her while intending to divorce her upon returning to your country, the majority of scholars hold this marriage to be valid. Before marriage, consult wise and righteous people and seek Allah's guidance through Istikhara. We also caution that residing in non-Muslim countries entails significant risks to one's religion and morals, so one should strive to reside in Muslim lands.