I'll start with a couple of concessions as to why this book isn't perfect, but hopefully I can then explain why it still gets 5 stars.
First, before reading this book I didn't know much about the Yugoslav wars, at most it was a footnote to other areas of knowledge - NATO strikes showed that international intervention could work for example. What this means is that when I say 'I now kind of understand what happened in Yugoslavia', what I mean is 'I now kind of understand what this book told me about Yugoslavia.' From a little google-ing The Death of Yugoslavia appears to be authoritative and trusted (and it certainly appears credible when reading it) but my knowledge of the period is now based primarily on this book. Take from that what you will.
Second, and this almost put me off picking up the book, it was written while the Yugoslav wars were still ongoing. This means by the end Milošević is still president, Mladic is a free man, etc. As the Kosovo war was to come in the late 90s it is also only briefly touched on. This did leave me with some questions, however the book does such a good job of explaining the situation on Yugoslavia that as a reader you're now fully equipped to Google the rest - you've got the context.
So why, given what could be a deal-breaking shortcoming, is this still a five star book? Because it's great, that's why.
The authors give a balanced, nuanced view of the conflict and its tiggers often giving the actors themselves the ability to explain their actions - either through snippets of speeches or direct interviews. This is backed up by the authors narration and analysis of events, meaning that you the reader know the 'facts' as to what happened, but also the rationale each player had for their actions. In a conflict so comprised of old wounds, new tensions and ideas of race/ethnicity/religion this is invaluable.
The Death of Yugoslavia is also immensely readable. While the names of people, places and organisations at first appear impenetrable the authors structure the narrative in such a way that you're never far away from a reminder who so-and-so is or which side they're on (and there's a glossary of people and acronyms included! INVALUABLE).
I read this book because I wanted to understand what happened in Yugoslavia, knowing only that there had been 'some sort of civil war' and maybe a genocide there. Now I know what happened there and I enjoyed learning it. What more can you want?