This is an excellent, well-written book about the policies of the US and UK concerning their intervention in Russia after its revolution. I would divide this book into two parts, although they are intermingled in the book:
1) the author's analysis of the various sources to understand what the key decision-makers knew about the situation in Russia and their thoughts about it. He quotes extensively from contemporary memos, letters, etc. and does a better job than other authors I've read to explain the various nuances between various actors' thoughts on intervention. This part of the book is excellent.
2) the second part of the book consists of the author's arguments as to why the Bolsheviks would have been crushed if the US and UK had been willing to make even limited efforts at intervention with removal of the Bolsheviks as its goal. While these arguments are well-written and raise issues worthy of consideration, ultimately I found them unconvincing, or I should say not wholly convincing. In any event, these parts of the book were also well-written and the author makes many good points.
Overall, a highly recommended read for anyone interested in the Russian Civil War, especially the "what if" aspects of it...