I wanted to like this book, I really did. My priors were that Samantha Power is an interesting, intelligent, and well-intentioned person. Which I continue to believe. And I agree with the majority of the comments, that the book is well written.
However, and this is a big however, she reveals what to me seems a huge blind spot, on the order of those exhibited by one of her mentors, Richard Holbrooke.
The blind spot is this. Ms. Power consistently praises the US for its diversity, while she consistently criticizes various other countries for genocide. What is wrong with this? It is certainly not wrong to criticize genocide! What is wrong is to ignore the important link between diversity and genocide. Genocide is an extreme response by governments to minorities in their populations from which the majority differs in some important way. Without those differences -- which can be ideological, religious, political, or racial -- there is no basis for persecution or discrimination of any sort of the minority(ies) by the majority, let alone for the extreme response of genocide. In short, diversity is a necessary but not sufficient condition for discrimination of all sorts, up to and including genocide. This is one lesson of history, and the examples are simply too many to ignore.
In short, Ms. Power appears to advocate diversity within nations as a purely good thing, while history teaches us that such diversity is a best a mixed bag. And so, Ms. Power appears to be asserting that governments can, going forward, constrain their citizens to react differently than citizens of the past have repeatedly done in the face of racial and other differences between them, which is to cluster in tribes and to distrust strangers. In short, she expects that governments are capable of altering basic human nature. That is one VERY optimistic assumption. It is especially problematic when one considers that ALL forms of government, not limited to democracy, provide strong incentives for those in power to cater to the power blocs in their populations in order to maintain control. And one way to do that, a way that is especially prominent in today's political world, is to demonize the opposition, in this case, those who differ in race, gender, politics, and/or religion from the majority.
It seems to me, when discussing policy in diverse populations, one should at least consider the possibility that diversity could be a governance problem, as it turned out to be for the US in Iraq and Afghanistan, for example. And in Bosnia. And in Yemen. This, I imagine, is the basis for support of a two nation solution to the Israeli-Palestinian conflict.
This issue is, of course a very large and contentious one. All the more reason why Ms. Power should have addressed it in her book. Otherwise it is, and unfortunately remains, the 800 pound gorilla in the room.