Political leaders employ unofficial diplomatic intermediaries for the same reason that they employ spies – to give themselves an edge. Go-betweens, as Karina Urbach calls them in this study of Hitler’s secret emissaries, bypass formal channels of communication. They engage in negotiations that are deniable and unfettered by public accountability. Thus in recent years British and American governments have engaged in clandestine discussions with terrorist groups such as the IRA and rogue states such as North Korea. Covert contacts are particularly valuable at times of crisis and all government heads resorted to them during the 1930s. Roosevelt used his crony Henry Morgenthau to help achieve US recognition of the Soviet Union. The French prime minister Edouard Daladier tried to secure better relations with the Axis powers through the intercession of the banker Paul Baudouin and others. Chamberlain authorised an egregious civil