If the retaliation is "small and subtle" and not really affecting the work balance on a professional level, it is not worth letting the VP go$.$ If the employee is able to remain professional and keep the personal matters aside for the most part, and is still doing an acceptable job as VP$,$ he should be able to stay. If the issues become of professionalism or productivity, it is more worth it to hire another VP or promote an exiting employee who is qualified. While he may be a friend, personal and work lives need to remain separate, especially in these situations. If the employee stays and the power struggle continues, it may affect other employees who notice this negativity or who are looking to be promoted to these positions. These employees may adopt these mannerisms from the employee, or integrate their personal lives further. into the workplace by choosing sides, which would just further the issue.