In historical terms, the Old Diplomacy is not really that old--many of its concepts and methods date to the mid-nineteenth century--while the practices of New Diplomacy emerged only a couple of generations later. Moreover, "Diplomacy 2.0" and other variants of the post-Cold War era do not depart significantly from their twentieth-century predecessor: their forms, particularly in technology, have changed, but their substance has not. In this succinct overview, historian Kenneth Weisbrode reminds us that to understand diplomatic transformations and their relevance to international affairs is to see diplomacy as an entrepreneurial art--and that, like most arts, it is adapted and re-adapted with reference to earlier forms. Diplomatic practice is always changing, and always continuous.