Is a Muslim husband obligated to force his Christian wife to wear the hijab and niqab and to observe modesty when going out and meeting non-mahrams?

A husband must command his wife to wear the hijab, whether she is Muslim or a woman of the book, because her exposure brings harm upon him. He must advise her to wear the شرعي (Shar'i) hijab. If the woman refuses to wear the hijab, she is considered disobedient to her husband and in violation of Allah's law. In this case, the husband must divorce her, whether she is Muslim or a woman of the book; this is to avoid evil and protect the family from harm. It is mentioned in the "Didascalia" of the Orthodox Christians that the hijab is obligatory for Christian women, as it protects them from the gaze of evildoers.