Definition
Reciprocity (Hu.: viszonosság elve, Ro.: principiul reciprocității, Gr.: αμοιβαιότητα) = A principle of international law, according to which a certain behaviour or action of a state towards another state, should be returned in kind. Extradition, grant of copyright to foreign authors, reduction of tariffs, visa requirements, mutual recognition of judgements, etc. are all good examples for the above mentioned behaviour.
The principle of reciprocity does not apply in international humanitarian relations, meaning that the obligation to respect international humanitarian law cannot be conditioned by reciprocity.
Useful Links
Legislation
https://treaties.un.org/doc/Publication/UNTS/Volume%201155/volume-1155-I-18232-English.pdf - 1969 Vienna Convention on the Law of Treaties [English]
https://ihl-databases.icrc.org/customary-ihl/eng/docs/home - Customary International Humanitarian Law Database [English]
Online Publications
https://odeenishmaeldiplomacy.wordpress.com/2013/08/19/41-reciprocity-in-international-relations/ - Ishmael O., Reciprocity in International Relations, Notes on Diplomatic Practice [English]
http://www.hscentre.org/latest-articles/principle-reciprocity-hidden-value-humanitarian-conventions/#_ftnref13 – Maniatakis A., Principle of Reciprocity: A hidden value in humanitarian conventions, Human Security Center [English]
http://scholarship.law.cornell.edu/cgi/viewcontent.cgi?article=1509&context=cilj – Paris F., Ghei N., The Role of Reciprocity in International Law, Cornell International Law Journal [English]
Publications
Byers, M., 1999, Custom, power, and the power of rules: International relations and customary international law, Cambridge; New York, Cambridge University Press [English]
Decaux, E., 1980, La Reciprocite en droit international, Paris, Librairie generale de droit et de jurisprudence [French]
Osiel, M., 2009, The end of reciprocity: Terror, torture, and the law of war, Cambridge; New York, Cambridge University Press [English]
By Angalit Toma