What is one characteristic of customary international law?

Customary international law is primarily characterized by its formation from the consistent and general practice of states, which is followed by them out of a sense of legal obligation. This means that customary international law arises organically from the behavior of states over time, reflecting a uniformity and acceptance of certain practices as legally binding.

The process involves two main elements: the actual practice of states (state practice) and the belief that such practice is legally obligatory (opinio juris). This distinguishes customary international law from written laws or treaties, as it does not need to be codified in formal documents to be recognized and enforced among nations.

The other options do not accurately represent the nature of customary international law. Unlike codified laws, customary international law can exist without written statutes. It is not limited to treaties; treaties are a separate source of international law. Furthermore, customary international law is not enforced solely by local courts, as its applicability often extends to international jurisdictions and can be recognized by various legal entities worldwide.