Diplomacy, the conduct of inter-state relations, is an old business, and has remained surprisingly constant across three millennia and five continents. Despite vast changes in its social and economic context, its goals and methods have remained strikingly similar over time, so as the shape of the character of the people active in it. Perpetually, it has the same core activities: representation, negotiation, observation, reporting, analysis and policy advice. Its meat and drink is politics, trade promotion, economic relations, and consular protection. But nowadays, its scope has widened to cover the whole range of government business in a global society. The diplomat operates in a field of tensions, between war and peace, depending on the relations between the sending and receiving state. He must be adaptable to both. Psychologically, he is always located somewhere along this spectrum, part man of peace, seeking a productive balance of interests, part man of power, seeking national advantage in the global struggle. He is by nature ambiguous: a voyager between two worlds, an interpreter between alien cultures, a man who can see both points of view and find common ground. He is a front-line officer who risks being shot in the chest or in the back. Internet: <http://www.diplomat21.com/diplomacy/necessity.htm> (with adaptations).