I think (as the previous reviewer with his concern about the Georgian diaspora appears to have done) it is easy to forget how ground-breaking and important the whole of Tom de Waal's book is, and just get wrapped up in the details. The group of writers doing serious research into the Caucasus who present their findings in a neutral, clear and reliable way is minute, and he is at their centre. He wears his huge knowledge very lightly and most readers would gain no idea from this small, excellent book how much serious work has gone into it.
His previous books have focussed on specific parts of the region (Chechnya and Nagorny-Karabakh), but this time he has taken on the whole South Caucasus and thus given a secure foundation for anyone wanting to find out about the region, or to do further research into it. Almost all other works that I know are either biassed (pro-Soviet, anti-Russian, pro-American), good but spread too thin (Charles King's the Ghost of Freedom) or just rubbish. His patient debunking of myths and establishing of narrative may not seem a glorious task, but it is necessary, and extremely useful to anyone coming to the Caucasus for the first time.
Nationalists from all three (or six?) countries of the region will hate it, since it skewers their favoured myths and gives fair hearing to the complaints of the opposite side. But if the countries' politicians really wanted to help build a war-free future, they should translate this into Abkhaz, Armenian, Azeri, Georgian, Mingrelian, Ossetian, Russian and Svan and use it as a textbook in every school and university they have.