Is it permissible for a husband to prevent his wife from working in a mixed-gender environment, even though she stipulated working in the marriage contract? And is it permissible for him to outwardly approve of her work, then secretly attempt to prevent her employment?

If the husband agreed to his wife working before the marriage contract, and the work adheres to Islamic guidelines (modesty, hijab, no free mixing, no neglect of the husband's and children's rights), then he has no right to prevent her. However, if any of these conditions are violated, he has the right to prevent her, because in that case, the work would contradict Islamic rulings or his personal rights. Such matters should be discussed frankly, unless the situation reaches an impasse between them, in which case a stratagem may be permissible to avert a greater harm. The husband is advised to show wisdom and gentleness, and the wife is advised to obey her husband, as this is among the most emphasized duties.