I wanted to give this book a higher score, because there are some really great things about it, but there are some weaknesses too.
The book is at its best when describing peacekeeping actions undertaken by the United Nations. As part of Bunche's staff for much of this time, Urquhart has a firm grasp on and a strong passion for the material, and the material is fascinating.
He does not do as well with the information leading up to that. This may be partly due to a reliance on information from a family cousin for the early chapters, dealing with Bunche's origin and education. The book is at its slowest while this material is being covered.
However, I think there are also some issues with Urquhart's instincts on how to handle that kind of information. This happens most frequently with references to the correspondence between Bunche and his wife. The strain of frequent separation frequently led to mutual recrimination, and sometimes very nasty letters are quoted, and other time they are very supportive, and I feel like it is not understood.
This is even more evident with their references to the children, whom they frequently worried about. At times the letters refer to failure and ruining the children, but no details on what would make them seem ruined. Eventually we learn that one daughter suffered from depression, and eventually killed herself, but there is no clear connection, or explanation of why both girls were ruined, instead of just the depressed one. Similar issues occasionally occurred on other subjects, but it was most prevalent with the family.
That means the book works less well as a biography, where you come to understand the man, and that is unfortunate because it is undoubtedly the best researched, most thorough work on Bunche available.
That being said, there is still much to admire. The United Nations aspects are fascinating, and it is worth learning more about Bunche, a remarkable man, and you do learn more--perhaps just not as much as would have been enjoyable.
There is still a lot of food for thought on issues of diplomacy, balancing personal needs against the greater good (in addition to family issues, his health suffered a great deal in pursuit of his causes), civil rights, black exceptionalism, and often just the difficulty of doing good when it is so easily sabotaged by others for reasons of pride, greed, or ignorance.