This is a pretty shocking look at Kissinger's record over a period of roughly 10 years (late 60s to late 70s), during which time he held titles such as US National Security Advisor, Chairman of the Forty Committee and Secretary of State. Specifically, the book accuses Kissinger of:
-deliberate mass killing of civilian populations in Indochina
-deliberate collusion in mass murder ... in Bangladesh
-personal suborning and planning of murder of a senior constitutional officer in a democratic nation - Chile - with which the US was not at war
-personal involvement in a plan to murder the head of state ... of Cyprus
-incitement and enablement of genocide in East Timor
-and last of all, involvement in a plot to kidnap and murder a journalist living in the US Capital
The evidence against Kissinger is in the form of extracts from autobiographies of the key players and material eventually released from Justice Department records. Nobody has sued Hitchens for this book, and they obviously can't now; either Kissinger's people treated the entire work as contemptible, or there might just be a few stones that they wanted to leave unturned.
Either way, if you're a Hitch fan, or someone who's interested in this period or the abuse of power, I thoroughly recommend this entertaining book. It's also a very good history lesson if you're too young to remember 50 years ago.