The principle of reciprocity occupies an important position in the jurisprudence of international relations in the Islamic legislation either in the case of peace or war. This study includes a clarification of this principle. Further, several Quran verses and Prophet Narrations that reinforce this principle at the individual and international levels are presented along with highlighting and controls to this principle. Then the study discussed some of controling the applications of this principle in terms of international relations in Islamic Fiqh, including: motive for fighting in Islam, and Al'shour (tithe tax), slavery, non-reciprocity of treachery and disloyalty, the treatment of captives, hideousness against the killed /dead, and diplomatic immunity. This study recommended to the importance of activating
Moayad H. Mousa , Abdullah I. Kelane
Reciprocity, International Relations.