We are here concerned with the extent to which international law permits a state to exercise its jurisdiction over persons or things in its territory and sometimes abroad. This issue is an aspect of the sovereignty of states, as reflected in the principles of the equality of states and non-interference in another state's domestic affairs. Domestic jurisdiction takes two main forms: prescription (the making of law) and enforcement (implementation of the law by the judiciary and the executive). Having been developed over the years, mostly by judgments of domestic courts, the principles are fairly well established. Conflicts of jurisdiction in civil matters are generally resolved by applying conflict of laws rules. Disputes over jurisdiction occur more often in the enforcement of laws of a regulatory nature. The main problem today is when the assertion of jurisdiction by a state adversely affects the commercial or economic interests of foreign nationals.

International law leaves a fair measure of jurisdictional discretion to states, which can assert jurisdiction if this can be justified by a permissive rule of international law.