What role does emotion play in modern diplomacy? Would the US reaction to 9/11 have been different if George W Bush had not needed to act as a Texas cowboy in order to hide his privileged East Coast upbringing? Would the Serbs have got a better deal in the post-Yugoslavia settlement if Slobodan Miloševic had had less of the dark about him? And would the Cold War have ended peacefully if not for Ronald Reagan’s immense personal charm and ability to fuddle the issues?

All historians worth their salt have accepted the role that emotion and personal politics play in international as well as domestic affairs. Sitting around the table negotiating with other world leaders is, after all, not so very different from being at a company board meeting or (God forbid) discussing an