Is it permissible for a man to divorce his second wife to appease his first wife, and what is the ruling of Islamic law on that?

It is not permissible for a woman to ask her husband to divorce his other wife, due to the Prophet's (peace be upon him) saying: "It is not lawful for a woman to ask for the divorce of her sister to empty her plate, for she will only get what is decreed for her." Divorce is disliked or forbidden if there is no need for it, and some scholars consider it forbidden in this case, because it causes harm and destroys a benefit without cause. However, if there is a need for divorce, such as the husband fearing for his children's welfare if he does not divorce the second wife, then it is permissible. A man must fear Allah and not rush into a second marriage so as not to harm anyone.