“The origins of diplomacy date back at least to the Bronze Age in the Near East. Caches of documents from the Euphrates kingdom in the mid–eighteenth century bc and from Akhenaten’s Egypt four centuries later reveal a regular exchange of envoys with neighboring states, prompted by the need for trade and the danger of war. This was hardly a fully fledged diplomatic “system.” Envoys were not resident ambassadors and they were not protected by agreed rules of immunity—but it was a recognizable form of diplomacy.”