Can divorce be avoided by offering expiation if the wife is compelled to do something upon which her husband conditioned her divorce?

If the husband says to his wife: "If you do that, you will be divorced," this is a promise of divorce and not a conditional divorce. Therefore, divorce does not occur when the action takes place. However, if he says: "If you do such and such, then you are divorced," this is a conditional divorce that takes effect when the action occurs, provided there is an intention to enact the divorce. If there is no intention of divorce, then there is a difference of opinion on the matter.