The title refers both to Milosevic and to the term he himself ironically once used to describe Serbian nationalism. Cohen ably recounts the Serb leader's use of the "serpent" in ascending to power and the conflicted role it continued to play in his post-1996 decline. But the story revolves around Kosovo -- not just the 1999 war and its aftermath but the region's tragic place in Serbia's recent history. In exploring the sad interaction of events in Serbia and Kosovo over the last decade and a half, Cohen is particularly good at sorting out the political alignments and strategies among elites in both places. On the blood-spattered issue of Serbian and Albanian nationalism, he does not disavow the commonplace wisdom that nationalism, at its worst, is a tool of unscrupulous leaders. Yet he cautions well-meaning Western policy engineers that the tool works because popular myths and poorly buried animosities create ready-made material.