Customary international law are those aspects of
international lawPublic international law concerns the structure and conduct of sovereign states; analogous entities, such as the Holy See; and intergovernmental organizations. To a lesser degree, international law also may affect multinational corporations and individuals, an impact increasingly evolving beyond...
that derive from
customCustom in law is the established pattern of behavior that can be objectively verified within a particular social setting. A claim can be carried out in defense of "what has always been done and accepted by law." Customary law exists where:...
. Along with general principles of law and
treatiesA treaty is an express agreement under international law entered into by actors in international law, namely sovereign states and international organizations. A treaty may also be known as an agreement, protocol, covenant, convention or exchange of letters, among other terms...
, custom is considered by the
International Court of JusticeThe International Court of Justice is the primary judicial organ of the United Nations. It is based in the Peace Palace in The Hague, Netherlands...
,
juristA jurist or jurisconsult is a professional who studies, develops, applies, or otherwise deals with the law. The term is widely used in American English, but in the United Kingdom and many Commonwealth countries it has only historical and specialist usage...
s, the
United NationsThe United Nations is an international organization whose stated aims are facilitating cooperation in international law, international security, economic development, social progress, human rights, and achievement of world peace...
, and its member states to be among the primary
sources of international lawSources of international law are the materials and processes out of which the rules and principles regulating the international community are developed. They have been influenced by a range of political and legal theories...
.
For example,
laws of warThe law of war is a body of law concerning acceptable justifications to engage in war and the limits to acceptable wartime conduct...
were long a matter of customary law before they were codified in the
Hague Conventions of 1899 and 1907The Hague Conventions were two international treaties negotiated at international peace conferences at The Hague in the Netherlands: The First Hague Conference in 1899 and the Second Hague Conference in 1907...
,
Geneva ConventionsThe Geneva Conventions comprise four treaties, and three additional protocols, that establish the standards of international law for the humanitarian treatment of the victims of war...
, and other treaties.
The vast majority of the world's governments accept in principle the existence of customary international law, although there are many differing opinions as to what rules are contained in it.
The
Statute of the International Court of JusticeThe Statute of the International Court of Justice is an integral part of the United Nations Charter, as specified by Chapter XIV of the United Nations Charter...
acknowledges the existence of customary international law in Article 38(1)(b), incorporated into the
United Nations CharterThe Charter of the United Nations is the foundational treaty of the international organization called the United Nations. It was signed at the San Francisco War Memorial and Performing Arts Center in San Francisco, United States, on 26 June 1945, by 50 of the 51 original member countries...
by Article 92: "The Court, whose function is to decide in accordance with international law such disputes as are submitted to it, shall apply...international custom, as evidence of a general practice accepted as law."
Customary international law "... consists of rules of law derived from the consistent conduct of
StatesA sovereign state, or simply, state, is a state with a defined territory on which it exercises internal and external sovereignty, a permanent population, a government, and the capacity to enter into relations with other sovereign states. It is also normally understood to be a state which is neither...
acting out of the belief that the law required them to act that way." It follows that customary international law can be discerned by a "widespread repetition by States of similar international acts over time (State practice); Acts must occur out of sense of
obligationAn obligation is a requirement to take some course of action, whether legal or moral. There are also obligations in other normative contexts, such as obligations of etiquette, social obligations, and possibly...
(
opinio juris); Acts must be taken by a significant number of States and not be rejected by a significant number of States." A marker of customary international law is consensus among states exhibited both by widespread conduct and a discernible sense of obligation.
The International Court of Justice (case of USA vs Nicaragua in 1989) held that the elements of an international customary law would be
Opinio Yuris (Past Judge Decisions or works of the most highly qualified publicists) which is then proven by existing state practices.
A
peremptory normA peremptory norm is a fundamental principle of international law which is accepted by the international community of states as a norm from which no derogation is ever permitted.There is no clear agreement regarding precisely which norms are jus cogens nor how a norm reaches that status, but...
(also called
jus cogens,
LatinLatin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for "compelling law") is a fundamental principle of international law which is accepted by the
international communityThe international community is a term used in international relations to refer to all peoples, cultures and governments of the world or to a group of them. The term is used to imply the existence of common duties and obligations between them...
of states as a norm from which no
derogationDerogation is the partial revocation of a law, as opposed to abrogation or the total abolition of a law. The term is used in both civil law and common law. It is sometimes used, loosely, to mean abrogation, as in the legal maxim: Lex posterior derogat priori, i.e...
is ever permitted. Examples include various
international crimesInternational criminal law is a body of international law designed to prohibit certain categories of conduct commonly viewed as serious atrocities and to make perpetrators of such conduct criminally accountable for their perpetration. Principally, it deals with genocide, war crimes, crimes against...
; a state which carries out or permits
slaverySlavery is a system under which people are treated as property to be bought and sold, and are forced to work. Slaves can be held against their will from the time of their capture, purchase or birth, and deprived of the right to leave, to refuse to work, or to demand compensation...
,
tortureTorture is the act of inflicting severe pain as a means of punishment, revenge, forcing information or a confession, or simply as an act of cruelty. Throughout history, torture has often been used as a method of political re-education, interrogation, punishment, and coercion...
,
genocideGenocide is defined as "the deliberate and systematic destruction, in whole or in part, of an ethnic, racial, religious, or national group", though what constitutes enough of a "part" to qualify as genocide has been subject to much debate by legal scholars...
,
war of aggressionA war of aggression, sometimes also war of conquest, is a military conflict waged without the justification of self-defense usually for territorial gain and subjugation. The phrase is distinctly modern and diametrically opposed to the prior legal international standard of "might makes right", under...
, or
crimes against humanityCrimes against humanity, as defined by the Rome Statute of the International Criminal Court Explanatory Memorandum, "are particularly odious offenses in that they constitute a serious attack on human dignity or grave humiliation or a degradation of one or more human beings...
is always violating customary international law.
Other examples accepted or claimed as customary international law include the principle of
non-refoulementNon-refoulement is a principle in international law, specifically refugee law, that concerns the protection of refugees from being returned to places where their lives or freedoms could be threatened...
,
immunityDiplomatic immunity is a form of legal immunity and a policy held between governments that ensures that diplomats are given safe passage and are considered not susceptible to lawsuit or prosecution under the host country's laws...
of visiting foreign
heads of stateA head of state is the individual that serves as the chief public representative of a monarchy, republic, federation, commonwealth or other kind of state. His or her role generally includes legitimizing the state and exercising the political powers, functions, and duties granted to the head of...
, and the right to
humanitarian interventionHumanitarian intervention "refers to a state using military force against another state when the chief publicly declared aim of that military action is ending human-rights violations being perpetrated by the state against which it is directed."...
.
See also
- Customary International Humanitarian Law
Customary international humanitarian law is a body of unwritten rules of public international law, which govern conduct during armed conflict.-Customary international law:...
- Crime against humanity
Crimes against humanity, as defined by the Rome Statute of the International Criminal Court Explanatory Memorandum, "are particularly odious offenses in that they constitute a serious attack on human dignity or grave humiliation or a degradation of one or more human beings...
- Genocide
Genocide is defined as "the deliberate and systematic destruction, in whole or in part, of an ethnic, racial, religious, or national group", though what constitutes enough of a "part" to qualify as genocide has been subject to much debate by legal scholars...
- Human rights
Human rights are "commonly understood as inalienable fundamental rights to which a person is inherently entitled simply because she or he is a human being." Human rights are thus conceived as universal and egalitarian . These rights may exist as natural rights or as legal rights, in both national...
- Public international law
- International humanitarian law
International humanitarian law , often referred to as the laws of war, the laws and customs of war or the law of armed conflict, is the legal corpus that comprises "the Geneva Conventions and the Hague Conventions, as well as subsequent treaties, case law, and customary international law." It...
- International human rights law
International human rights law refers to the body of international law designed to promote and protect human rights at the international, regional and domestic levels...
- Refugee Law
Refugee law is the branch of international law which deals with the rights and protection of refugees. It is related to, but distinct from, international human rights law and international humanitarian law, which deal respectively with human rights in general, and the conduct of war in...
- Rule of law
The rule of law, sometimes called supremacy of law, is a legal maxim that says that governmental decisions should be made by applying known principles or laws with minimal discretion in their application...
- Rule according to higher law
The rule according to a higher law means that no written law may be enforced by the government unless it conforms with certain unwritten, universal principles of fairness, morality, and justice...