In addition, civil wars, human rights abuses, famine, terrorism, air hijackings, drug smuggling, and nuclear proliferation are just some of the pressing concerns that have become internationalized. It is evident that the globalization of so many social and economic issues has caused significant changes in the practice of domestic law. Thus, those individuals who are interested in the practice of the law cannot ignore the newfound importance of international law. With so many nations and cultures to be considered in the spectrum of international law, and the lack of an effective international law enforcement body, it is surprising that many countries are willing to adhere to the principles of mutual cooperation. In fact, many states incorporate agreed principles of international law into their own domestic laws.
Customary law is essentially the law of civilized nations.
Specifically, these issues are founded on the general principles common to civilized countries of the world. For illustration, consider these examples of customary law. First, most countries recognize that other nations exist as independent states. As a result, the customary law of sovereignty precludes that these independent states must co-exist with each other. Secondly, civilized nations accept the freedom of the seas.