Diplomacy can be regarded as the management of official relations between the governments of States. Whereas the terms diplomacy and foreign policy are often used interchangeably, diplomatic relations are an instrument of foreign policy. Diplomatic negotiations are used to the accomplishment of foreign relations. The purpose of diplomacy is to strengthen the State and to serve in its relations with others. One of the functions of diplomatic relations is to minimize frictions and conflicts with other states through negotiations.

There are three kinds of diplomacy. The first is bilateral, and concerns diplomatic relations between two states (i.e. diplomatic representation of the sending state in a receiving state). The second is multilateral, which  involves diplomatic relations regarding regional or global issues and is used with a plurality of States through an international organization or at international conferences. And the third is ad hoc diplomacy, which involves other forms of diplomacy than the two aforementioned types. For example, one can think of special missions to which States resort in order to entrust a diplomatic officer with the task to carry out one or many diplomatic assignments in a foreign State even though this officer does not belong to a permanent mission accredited to a country. In Academia, diplomatic studies is regarded as a new discipline, a sub-area of international relations.

The main instruments are international organizations and international alliances. Diplomacy itself is an essential and primary tool of foreign policy. Foreign policy is implemented with the help of the instrument of diplomacy.

Diplomatic law, which is part of public international law, regulates diplomatic relations between states and international organizations. It also governs legal aspects of diplomatic immunity, and diplomatic privileges. Diplomatic law is also concerned with topics such as the security of diplomatic correspondence and diplomatic bags and the inviolability and immunity of diplomatic missions and their grounds. Immunities and privileges are granted to diplomats in order to fulfill their mission and carry out their functions in an effective manner. Consular law is, for example, is concerned with legal aspects of consular relations, and privileges and immunities of consular officers and consular posts.

This Research Guide is intended as a starting point for research on Diplomacy. It provides the basic materials available in the Peace Palace Library, both in print and electronic format. Handbooks, leading articles, bibliographies, periodicals, serial publications and documents of interest are presented in the Selective Bibliography section. Links to the PPL Catalogue are inserted. The Library's subject headings (keywords) Diplomacy, Diplomatic Law, Diplomatic and Consular Immunities and Diplomatic History are instrumental for searching through the Catalogue. Special attention is given to our subscriptions on databases, e-journals, e-books and other electronic resources. Finally, this Research Guide features links to relevant websites and other online resources of particular interest.