Public International Law (PIL) rests upon two core concepts enmeshed in each of its underlying regimes: those of sovereignty and non-intervention. These privileges are allotted only to recognized States as qualified by the standards set forth in the Montevideo Convention of 1933. Article 1 of the Convention articulates that “the state as a person of international law should possess the following: a) a permanent population; b) a defined territory; c) government; and d) capacity to enter into relations with other states”.1 Non-intervention of States into the affairs of other States is a far-reaching principle with only two exceptions: Security Council authorization under Chapter 7 of the UN Charter, and self-defense. Sovereignty is a more detailed principle as States strip away particular aspects of their sovereignty with each treaty and agreement signed. Beyond governing States, PIL also regulates international organizations and the relationships among these organizations, States, and individuals.
The sources of PIL are international conventions, international custom, the general principles of law recognized by civilized nations, and judicial decisions and the teachings of the most highly qualified publicists of the various nations.2 While States may decide which conventions to ratify, international customary law applies to all State regardless of consent. To qualify as international custom, a law must be a consistent and general practice among States and must be adhered to by those States out of a sense of legal obligation rather than political action or diplomacy.
The legal regimes within PIL which most relate to humanitarian action are International Humanitarian Law (IHL), International Human Rights Law (HRL), and Refugee Law.