My response is…
Never forget that “culture eats strategy for breakfast” (Peter Drucker, I believe). Interpersonal problems may reflect more than the personal issues of one or more employees. Your people interact based on their Identity (who am I?), their Relationships (who are we?), and the flows of work and info among them (what will we do together?). The dynamics of power and fear can amplify negative values and behaviors in the workplace. That can and will hurt productivity and effectiveness.
Ignoring the problem makes you a part of the problem. So tell your people what you expect. Tell them that whatever their differences, they must be able to interact respectfully, and work together effectively. Provide learning and a process to address serious complaints in a neutral and confidential way, such as an ombuds program. Measure the levels of engagement and trust in your workplace, along with your productivity and success. Acknowledge progress and challenges. Remove those who ultimately can not or will not change.