Three criteria for stepping inStep in when at least one of these holds:
• The work suffers: deadlines, quality, clients. A tester and a developer haven't handed each other tasks for a week — that's no longer “their relationship.”
• Third parties suffer: the team is being pulled into camps, juniors are used as couriers for grievances, meetings feel like a minefield.
• Boundaries are crossed: insults, humiliation, getting personal. Here you step in immediately, no exceptions: stay silent, and the whole team hears that this is acceptable.
If none of them holds, stay out. Adults have the right to dislike each other and quietly do good work.
The overprotection trap: a manager who rushes to resolve every argument trains the team to resolve nothing on its own — and every little thing gets escalated to him.
The first move when in doubt isn't a public showdown but a short conversation with each person separately: the facts and “how does this look to you?” If the conflict isn't deep, offer to let them settle it themselves, with a deadline: “talk it through, just the two of you; if it's not settled by Friday, the three of us will sit down.”