As has aptly been said: When stable communities—whether Tribes, or City-States, or States of a modern type—are permanently contiguous, customs hardening in time into law never fail to regulate their intercourse. Ubi societas, ibi jus; wherever developed communities are brought in contact with each other, juridical relations must sooner or later be formed not mainly by agreement, tacit or express, but by the very necessity of the case, and partly from the same causes as those which working internally create States. 1 In other words, International Law means rules of the conduct of States in their mutual dealings. Obviously, it is not necessary that there should be only one set of rules, or one system of international law, at a time, for the conduct of all the States of the world. And several systems of international law could, and in fact did, exist simultaneously in different parts of the globe. Even the modern, so-called European, International Law is not a collection of unanimously approved rules.

Islam has elaborated its own system of public international law. Before describing it in detail, it might be useful to define precisely what I mean by the term Muslim International Law. It is to note by the way that throughout this book I have used “Muslim Law,”“Islamic Law” and “Fiqh” as synonymous terms. Muslim International Law may be defined as: That Part of the law and custom of the land and treaty obligations which a Muslim de facto or de jure State observes in its dealings with other de facto