In international arbitration doubts regarding an arbitrator’s impartiality can undermine the integrity of the proceedings, compromise the enforceability of the award, and damage the arbitrator’s professional reputation. Personal connections, professional networks, prior work experience, and past collaborations may often matter. This raises a critical question: where does the professional familiarity end and unacceptable bias begin? Based on practical examples and own experiences the panelist will explore the real-world dilemmas—from institutional perspective to the impact of geopolitical tensions and to concerns over personal connections.