A serious student with a certain background in Tibetan and Chinese history may find this book useful -- perhaps even indispensible. For everyone else, it may prove impenetrable. The two maps are almost totally worthless, and the text assumes a basic familiarity with place names and non-Tibetan figures that is inconsistent with a general survey. My background is in the Near East and Central Asia; where Beckwith referred to place names in those areas, I understood him well, but when discussing Tibet or China, I did not.
The same is true of facts concerning contemporary empires. The Abassid revolution, for example, is mentioned only in passing, without any kind of discussion on its effect on Tibet and Central Asia. Obviously an in-depth discussion of the Abbassids is not necessarily appropriate for a monograph on Tibet, but Beckwith's greatest strength (his focus on Tibet's neighbors to explain events in Tibet) makes it a virtual necessity for this book.
This book is a political and military history. If you want details on Tibetan religion, culture, or literature, you will not find them here. Rather, we have a catalogue of battles, a desciption of waxing and waning influence in the Central Asian power struggles. I concede I may be asking the impossible -- not being a specialist, I don't know if such information even exists. Of course, Beckwith could have so stated.
The book starts and ends abruptly. The formation of the empire is disposed of with a few paragraphs. The disintigration of the empire is noted simply, with no discussion whatsoever of the decline that led to it, or the reasons that the once-mighty empire was irrevocably broken.
The book contains what should have been a helpful table of contemporary rulers. But the Tibetan names used in the text are not always the same as those used in the table, making it confusing and practically worthless for the non-specialist. And the Tibetan succession cannot easily be pieced together from the text alone because of the huge gaps in the narrative where the author focuses on other nations, such as Turgis campaigns against the T'ang.
In a sense, this is not a history of Tibet itself, so much as a history of all the major powers in Central Asia and their relationships with one another during the time period in which Tibet constituted an imperial power. That is useful as far as it goes, of course, but leaves Tibet itself almost as unknown at the end of the book as at the beginning.
I would recommend this book to specialists, except that specialists probably do not need it. I cannot recommend it to non-specialists, because of the many problems with it.