Diplomacy is the conduct of relations between states (and other international actors) through dialogue, negotiation and representation — the peaceful instrument of foreign policy; power's intelligence, in Morgenthau's phrase. Where foreign policy decides what a state wants, diplomacy is how it is pursued short of war: the machinery of missions and ministries, and the craft of persuasion.
Definitions to quote:
• Ernest Satow (the classic, from A Guide to Diplomatic Practice): diplomacy is "the applicationof intelligence and tact to the conduct of official relations between the governments ofindependent states."
• Harold Nicolson: the management of international relations by negotiation; the method by which these relations are adjusted and managed by ambassadors and envoys.
• Joseph Nye: diplomacy as communication with a purpose — one of the instruments of smart power.
Functions of diplomacy (the standard list): representation; negotiation; protection of the sending state's interests and nationals; reporting and information-gathering (lawful observation); promotion of friendly relations (trade, culture, science); and — the lawyer's addition — treaty-making and legal advocacy (the Vienna Convention on Diplomatic Relations, 1961, codified these in Article 3 — Unit 6).
Techniques of diplomacy (the negotiating craft — the syllabus keyword):
1. Negotiation — the core: preparation (interests, BATNA, fallbacks), presentation, bargaining (package deals, constructive ambiguity, sequential concessions), deadlock-breaking, and implementation;
2. Persuasion and argumentation — appeal to interest, precedent, law and legitimacy;
3. Confidence-building and protocol — the small courtesies that make adversaries talkable;
4. Good offices and mediation (third-party techniques — Unit 6);
5. Deadlock management — adjournment, formula-and-details method, single negotiating textss;
6. Signalling — démarches, summonses, recalls, expulsions: the escalation-and-de-escalation grammar of state displeasure;
7. Multilateral coalition-building — caucus, group coordination (NAM, LDC, LLDC caucuses where Nepal lives).