What is the Sharia ruling on dealing with a non-Muslim wife who prevents the children from embracing Islam, despite a prior agreement to that effect, given the laws of the country that side with the wife?

The fundamental principle is that a Muslim man should marry a Muslim woman to achieve harmony and raise children in an Islamic manner. However, it is permissible, though disliked (makruh), to marry a chaste woman from among the People of the Book, especially in their lands, due to the concern of increasing their numbers and the fear of apostasy. In such a case, the child is definitively considered Muslim. If the child chooses the mother's religion after reaching puberty, he is considered an apostate, which highlights the great responsibility of the father in protecting his child from deviation. The father should strive to separate his son from the mother and divorce her.