This is a final exam. I would like somebody to write 5 pages for each question following the instructions below. Your answers should be from your own words after reading the course readings I have attached.

Unit Learning Objectives

After reading this unit, you will:

· Have knowledge of where to find evidence of International Law and of how these laws are made (i.e. its sources)

· Have knowledge of some of the key principles guiding the operation of International Law and understand how to interpret these principles

· Identify the relationship among the various sources of International Law, and assesstheir strengths/weaknesses.

Unit Plan and Summary

This unit discusses the sources of international law. After outlining the distinction between 'hard' and 'soft' international law, the unit discusses the primary and secondary sources of hard international law, and identifies the key principles guiding the operation of these sources. The unit concludes with a discussion of the relationship among the primary sources of international law.

Outline

1. Sources of International Law

1. Primary Sources: Treaties, Customs, General Principles

2. Secondary Sources: Judicial Decisions & Legal Opinions

2. The Hierarchy of Sources

3. Soft International Law

Readings

· Epps, Valerie. “ Sources of International Law .” In International Law, 5-29. 4th ed. Durham, NC: California Academic Press, 2009.

· Abbott, Kenneth W, and Snidal, Duncan. “ Hard and Soft Law in International Governance .” International Organization 54, no. 3 (2000): 421–456. doi:http://dx.doi.org/10.1162/002081800551280..

Key Concepts

· Adoption and Accession

· Customs (Customary Rules of International Law)

· Desuetude & Abeyance

· Effective Date

· General Principles of Law

· Hard and Soft International Law

· Hierarchy of Sources

· Opinio Juris Sive Necessitatis

· Pacta Sunt Servanda

· Peremptory Norms (Jus Cogens)

· Provisional Application

· Obligatory and Permissive Rules

· Ratification

· Registration & Publication

· Reservations

· Rebus Sic Stantibus

· Treaties and Conventions

· Usus

Sources of International Law

In unit 1, we noted that unlike domestic legal systems, there is no world government or global legislative body to make laws in international relations. The United Nations (UN) General Assembly, the most universal international organization (and the closest thing to a global legislative body) can pass resolutions, but these resolutions are generally not legally binding and do not have the force of law. If there is no global legislature to make laws, where does international law come from? Where do we look for evidence of international law?

The word 'sources' of international law refers where to find evidence of international law. The Statute of the International Court of Justice (ICJ, Article 38 [1]) lists the following as the primary sources of international law. 1

1. International Conventions and Treaties

2. International Custom

3. General Principles of law

The ICJ also lists the following as subsidiary or secondary sources of international law:

4. Judicial Decisions

5. Opinions of Legal Scholars

This list, however, is not exhaustive because modern international law has evolved in ways unforeseen when the original version of Article 38[1] was drafted. 2  Newer sources include the rules and regulations developed by international institutions, and the increasing use of informal agreements. The term 'soft law' describes these newer sources to distinguish them from the 'hard law' sources listed in Article 38[1]. The following discussion examines the 'hard' sources of international law.

Primary Sources of International Law

International Treaties and Conventions

A treaty is an explicit agreement between two or more parties specifying rights and obligations between those parties. The term 'convention' is a synonym for 'treaty' and describes a treaty negotiated under the auspices of an intergovernmental organization such as the UN. 3  Treaties constitute states' explicit acceptance of rights and duties among themselves. There are different ways of classifying treaties. One way is by reference to what they do:

Codification Treaties (law-affirming treaties)

These types of treaties affirm, formalize and make explicit rights and duties contained in existing customary rules of international law by putting them in written form (i.e., codifying the rules). Examples include the Vienna Conventions on Diplomatic Relations (1961 & 1963), which codified existing customary rules regarding consular relations and diplomatic immunities.

Legislative Treaties (law-making treaties)

These treaties create new rules where none existed before, specifying new rights and duties that the parties to the treaty are expected to observe. Examples include regional trade and economic treaties such as the North American Free Trade Agreement (NAFTA, 1992).

Treaties can also codify and legislate. Examples include the UN Charter (1945) and the third UN Convention on the Law of the Sea (UNCLOS III, 1982), both of which codified existing customs and created new rules.

Another way to classify treaties is by reference to the number of parties to the agreement:

· Bilateral Treaties have two state parties;

· Multilateral Treaties have three or more parties.

The Treaty Making Process

The treaty-making process normally involves several steps:

· Adoption: fixes the terms of a treaty draft, usually the outcome of a negotiated agreement. Once adopted, no subsequent changes to the treaty text can occur except under the terms of the treaty. Adoption of bilateral treaties is by mutual consent and multilateral treaties by either unanimous consent or the consent of two-thirds of the parties to the agreement.

· Signature: after adoption, parties sign the agreement indicating their acceptance of the treaty's terms.

· Accession: a state that did not participate in drafting a treaty may become a party to that agreement (i.e., accede to it) by signing the agreement. Accession requires the consent of at least one other state party.

· Ratification: is a formal act or announcement by a government that it will abide by the treaty provisions. Unit 3, where we examine the relationship between international law and domestic (or municipal) law, discusses in detail the exact processes for ratifying treaties, which vary among states.

· Reservation: is a rejection, or special interpretation, of particular treaty provisions. A state may express reservations before ratifying a treaty. Reservations modify a state's treaty obligations, and require acceptance by at least one other state before the treaty binds the reserving state.

· Effective Date: Most international treaties specify a date and a required number of ratifications for the treaty to come into effect (i.e., to create legally binding obligations). 4

· However, states may bring a treaty into effect before the required number of ratifications, a process known as provisional application. 5

· The final step involves registration and publication of the treaty by the UN. 6

There are several reasons why treaties require ratification and registration/publication. First, signing an international agreement is not sufficient to create binding international laws. Binding obligations are normally only created after treaties come into effect through ratification (the provisions of treaties codifying existing customary rules are legally binding even if treaty is not in effect). Second, because treaties are normally binding only after ratification, prompt ratification by the signatories ensures a degree of reciprocity, which minimizes problems that may arise where states that initially ratify a treaty disproportionately carry the burden of compliance. Third, registration and publication increase transparency and reduce uncertainty about the treaty contents. 7  Publication also enhances a treaty's legitimacy by ensuring its wider international recognition.

Operation of Treaties – Some key principles

The Vienna Convention on the Law of Treaties (adopted in 1969, entered into force in 1980) 8  specifies some key principles guiding the operation of treaties, including the conditions for the validity of treaties and the circumstances for the legal termination of treaties.

Validity of Treaties

The following are the conditions under which a treaty is valid (or invalid) in international law.

Capacity to contract

Only recognized international 'legal persons' can become parties to a treaty. Unit 5 discusses how international legal personality is established and who/what qualifies as a legal person. For the most part only recognized sovereign states and under certain conditions, international organizations created by and for states (such as the UN), qualify as legal persons in contemporary international law.

Authorized agents

Only authorized agents of legal persons can negotiate and sign treaties.

Fraudulent negotiation

A treaty is invalid if there is evidence of fraud (intended or deliberate deception) in the negotiation of the treaty.

Substantial error

A treaty is voidable if there were substantial factual errors (unintended) during negotiations.

Corruption of state official

A treaty is voidable if an authorized agent of a state is corrupted during negotiations (e.g., through bribery). This provision was included at the insistence of developing countries concerned that corruption of their officials could result in treaties that were not in their best interests.

Consent

For a treaty to be valid, parties to the treaty must enter into it out of their own free will.

Coercion/Duress

The negotiation of treaties is to occur in good faith, without duress, and with the consent of negotiating parties. Under certain circumstances, a treaty is voidable if the negotiating agent of a state is subject to personal duress (e.g., threats, blackmail, etc). However, the existence of duress or coercion is not always sufficient to invalidate a treaty, and a treaty can still be valid once the state under duress gives its assent. For example, the imposition of a peace treaty on a state that is defeated in war (e.g., the Austrian Peace Treaty of 1955 that imposed neutrality on Austria).

Peremptory Norms/Jus Cogens (Latin for Compulsory Law)

This principle limits a state's ability to create its own rules by stipulating that a treaty is void if it violates basic principles of international law or accepted standards of morality. The technical name for Jus Cogens is "Peremptory Norms of General International Law". Article 53 of the 1969 Vienna Convention on the Law of Treaties defines a peremptory norm as "accepted and recognized by the international community of states … as a norm from which no derogation is permitted and which can be modified only by a subsequent norm … having the same character." Although analysts disagree over the content of these norms, most agree they include norms against the unilateral and aggressive use of force, norms upholding self-determination of peoples, and norms against genocide, slavery, apartheid (systematic and institutionalized racial discrimination) and other "crimes against humanity." Some analysts point to the UN Charter as evidence of peremptory norms, because the provisions of the UN Charter supersede any other treaty.

"accepted and recognized by the international community of states … as a norm from which no derogation is permitted and which can be modified only by a subsequent norm … having the same character."

UN Charter

The Charter of the UN came into effect in 1945. As a treaty, it is the single most authoritative document in contemporary international law. If there is a conflict between the provisions of the UN Charter and that of any other treaty, the UN Charter takes precedence. A treaty is voidable if it conflicts with the UN Charter, as specified in Article 103 of the UN Charter.

Termination of Treaties

Pacta Sunt Servanda 9  (Latin for "promises must be kept")

This is one of the most important principles governing treaties and goes to the core of the reciprocity underpinning international legal obligation discussed in Unit 1. All states, once they have ratified a (valid) treaty, are obliged to honour its provisions, and they can only terminate their treaty obligations under specified conditions:

· Terms of the treaty: Some treaties specify conditions and procedures for terminating states' treaty obligations.

· Mutual Consent: State parties may terminate a treaty by mutual consent.

Rebus sic stantibus (Latin for "things remaining as they are")

Also known as the doctrine of "fundamentally changed circumstances," relieves states from treaty obligations only if they can show that circumstances when the treaty was signed have changed so fundamentally that the provisions can no longer be honored or are no longer relevant. 10  As an example of a situation to which rebus sic stantibus might apply, soon after its inauguration in 2001, the US Bush Administration announced its withdrawal from the Anti Ballistic Missile (ABM) treaty signed with the USSR (now Russia). This treaty limited the development of ABM technology and the deployment of such weapons on either side (two sites each). From the US perspective, the circumstances under which the ABM treaty was signed in 1972 (when only five states possessed nuclear weapons) had changed fundamentally. New threats to US security were posed by the proliferation of nuclear weapons and other "weapons of mass destruction" (WMD) including biological and chemical weapons to so-called "rogue states" such as North Korea and Iraq. In response to these new threats, the US government initiated plans to build a missile defence shield to protect the continental United States.

"Supervening impossibility of performance"

Stipulates that a state may be relieved from treaty obligations due to the destruction or disappearance of an object indispensable to fulfilling its obligations. 11

Desuetude and Abeyance

Desuetude describes a situation where one or more parties to a treaty consistently and flagrantly ignore the treaty with no objection from others. In such instances, the treaty has fallen into abeyance and its provisions are no longer binding.

Emergence of new Peremptory Norms (Jus Cogens)

No treaty can violate a peremptory norm. Thus, if new peremptory norms emerge that conflict with a pre-existing treaty, state parties are relieved of their obligations even if the treaty was valid before the new peremptory norm emerged.

State Succession/Extinction

When a state ceases to exist (i.e., becomes extinct) its treaty obligations are terminated. Unit 4 discusses the legal consequences of state succession.

War

The outbreak of war between parties to a treaty relieves them of some (but not all) of their treaty obligations. Units 8 and 9 discuss in detail some of the laws of war, and how war affects treaties.

International Customs

International customs describe what states actually do out of a sense of legal obligation. Unlike treaties and conventions, therefore, customs are unwritten –– the customary rules are expressed in actual state practices. As a result, unlike treaties, identification of customary rules of international law is not clear-cut. There are, however, several ways to identify customs:

Identification of International Customs

· Observe the actual practice of states (official government reports, news reports, etc.) One problem, however, is that a state's actual policies may diverge from its statements.

· Since rules of international law govern state behaviour in relationship with other states, in identifying customs it is necessary to examine not only a state's actions (or inaction), but also the reaction of other states.

· Infer customs from treaties. However, this is not always the case. (e.g., an extradition treaty: does this provide evidence of an existing custom, and if so, why the need for a treaty in the first place?

· If the treaty in question codifies existing customs, or is declaratory of them, then that treaty provides evidence of customary law even against states that are not parties to the treaty.

· Customs may change to conform to an earlier treaty.

· Under certain conditions, resolutions of international organizations (such as the UN General Assembly) can provide evidence of customary law. However, resolutions passed by international organizations are not reliable evidence of customs. Unit 5 discusses this in more detail.

· Examine the decisions of international courts and tribunals. This is one of the most reliable ways of identifying international customs. The Scotia Case (US Supreme Court, 1872) provides an example of identifying customs through judicial decisions (see text Box 1).

Box 1

The Scotia Case ['Berkshire' vs. 'Scotia' US Supreme Court, 1872]

Facts of the case

A collision occurred between a US sailing vessel, the 'Berkshire', and a British steamer, the 'Scotia'. The 'Berkshire' sank. The owners of the 'Berkshire' sued in a US district court to recover losses, claiming that the loss of their ship was the fault of the 'Scotia'. District court ruled against plaintiff (owners of the 'Berkshire'). The case was appealed to a higher court, a US Circuit court, which upheld the lower court ruling. The case was finally appealed to the US Supreme Court.

At the time of the incident (at night), the 'Berkshire' did not display any coloured lights but only white lights fastened about four feet above the deck level. Regulations at the time (maritime customs) stipulated that coloured lights were to be used. The 'Scotia', acting in accordance with the regulations, mistook the white light of the 'Berkshire' for the masthead of a steamer and thus presumed the steamer was some distance away (because it looked smaller). When the incident occurred, the 'Scotia' was in full accord with all the existing rules regarding maritime sailing and steering.

The decision

US Supreme Court upheld the decision of the Circuit Court. The 'Berkshire' was deemed to have violated a customary law of the sea.

Issues

Was the law of the sea prevailing at the time the collision occurred? Yes. The British government had issued regulations regarding maritime sailing. Almost all (3/4) of the maritime nations of the time had agreed to these regulations. Thus the regulations regarding steering and sailing the high seas were generally accepted customary practices, and thus the practice established by a state (the dominant maritime power at the time) had evolved into a legally-binding custom.

(For fuller discussion, see von Glahn, p.18)

Principles Governing International Customs

There are several principles guiding the identification and operation of international customs:

Usus (Latin for 'usage')

There are two key components of usus: Consistent and recurrent action, and passage of time. For a custom to exist, the practices of states must be consistent and recurrent over time. This is important because creating a new custom is a slow process. In many cases, a given practice did not become a legally binding custom for several hundred years. A single action or precedent is often not sufficient to establish a custom. There must be a degree of repetition over time. Another major problem with identifying customs is inconsistency in the practice. If there are major inconsistencies, then it is not a custom. Minor inconsistencies, however, do not prevent the formation of customs. The Asylum Case (text Box 2) helps to illustrate the importance of usus in identifying customs.

The Asylum Case reveals that in trying to ascertain whether a given practice has become a custom the issues to consider include:

a. The number of states that follow the practice

b. The identities of those particular states

c. Whether they follow the practice because of a sense of legal obligation, and

d. Whether there is any competing practice.

The issue is clearer if both states involved in a dispute follow the custom.

Box 2

The Asylum Case [Columbia vs. Peru ICJ 1950]

Facts of the case

This case involved the claim of Columbia to give political asylum to a Peruvian national, Haya de la Torre, who had sought refuge in the Columbian embassy in Lima, Peru. Columbia claimed to have the right to determine whether it was the proper case for asylum and asked the ICJ to make a ruling as to whether a custom existed specifying how and when political asylum could be granted. Peru protested against Columbia's granting of political asylum to one of its nationals. Columbia argued that there was a regional custom among Latin American States governing the granting of asylum.

The decision

The ICJ ruled against Columbia arguing that there was too much inconsistency in the practices of Latin American states regarding the granting of asylum. The Court noted that "The facts brought to the knowledge of the court display so much uncertainty and contradictions...the practice has been influenced so much by political expediency...the court therefore, cannot find that the Columbian government has proved the existence of such a custom.'

Obligatory and Permissive Rules

In addition to usus, when inferring a custom, it is necessary to examine not only what states do (and say) but also why they do it. In the Lotus Case (see text Box 3), the Permanent Court of International Justice (PCIJ), the predecessor to the ICJ, established that there is an important psychological or normative element in the formation of international customs. This is because customs createobligatory rules and permissive rules. Each of these rule types can either impose duties on states thereby constraining their actions or create rights for states, thereby enabling/facilitating certain actions.

· Obligatory Rules (Duties), also known in the Latin as opinio juris sive necessitatis ("of the opinion that it is a necessary law"). 12 Obligatory rules impose duties on states. These customs require states to take particular actions, or refrain from acting. States' base their actions on the conviction that the rule creates a legal obligation to engage in (or refrain from) a certain form of conduct. Examples of obligatory customs include rules regarding diplomatic and consular immunities, and the rights of resident aliens (discussed in Units 5 and 8).

· Permissive Rules (Rights): In addition to creating duties, there are also permissive rules that confer rights upon states (allows them to act in a particular way without making such acts obligatory.) States' base their actions on the conviction that the rule permits a certain form of conduct. Examples include the rules on extra-territorial jurisdiction involving prosecuting foreign criminals outside a state's territory, discussed in Unit7.

Box 3

The Lotus Case [France vs. Turkey PCIJ 1927]

Facts of the case

A French merchant ship, the 'Lotus', collided with a Turkish merchant ship, the 'Boz Kourt' on the high seas, allegedly as a result of negligence on the part of Lt. Demons, an officer on the French ship. Several people on the Turkish ship drowned. France had jurisdiction to try Lt. Demons for manslaughter. The dispute was about whether Turkey also had jurisdiction to try him. Turkey argued that there was a permissive rule in international law that gave it the right to try Lt. Demons, a French national. France argued the opposite: there was a custom imposing a duty on Turkey not to try Lt. Demons.

The decision

The PCIJ ruled in favour of Turkey and against France

Issues

Permissive vs. Obligatory rules:

a. Although there were only a few cases in which states in Turkey's position had prosecuted, the other affected states concerned in those cases had not protested the prosecutions.

b. There was no evidence that there was a legal obligation on the part of Turkey to refrain from prosecuting Lt. Demons. Although most states in Turkey's position had refrained from prosecuting, this was not done out of a sense of legal obligation but for other reasons such as courtesy, political expediency, etc.

(For fuller discussion, see Bishop, pp. 536-551).

Change in and emergence of new customs

Another important issue is the question of how customs change and new ones emerge. The Fisheries Case (text Box 4) shows that the practice followed by a small number of states, even a single state, is sufficient to create a new custom provided the new practice meets the following conditions:

a. It is persistent and recurrent over time (usus)

b. No other practice conflicts with the new practice, and

c. Other states do not object when that practice is first introduced. This latter condition is known as persistent objection.

Persistent Objection:

For any given state to be exempt from a new custom, it must state its objection publicly from the earliest beginnings of the new rule. Dissent expressed after the rule has come into effect is not recognized. If some states claim a new rule and other states do not challenge it, a new custom will emerge. When the two groups are balanced, change is difficult. However, no state is legally bound to observe a custom if it changes later on. New states are bound by generally accepted customs, and cannot claim exemption from them.

Box 4

The Fisheries Case [United Kingdom vs. Norway ICJ 1951]

Facts of the case

The UK objected to Norway's delimitation of northern Norwegian territorial waters under a 1935 Norwegian decree. This decree used a particular technique (straight baselines) to measure the breadth of Norwegian territorial waters (up to 4-miles). The UK argued that Norway's action constituted a breach of international law because it used a technique unrecognized under existing customary rules to measure its territorial sea.

The decision

The Court ruled in favour of Norway against the UK. While recognizing that the delimitation of territorial waters was an international act and could not be unilaterally undertaken by a state, the court upheld Norway's 1935 decree for the following reasons:

a. When the decree was first promulgated, no other state, including the UK, had protested or challenged it.

b. The Norwegians had been consistent. Earlier Norwegian delimitation decrees in 1869 and 1889 were consistent with that of the 1935 delimitation decree (using the straight base-line measuring technique).

c. The Norwegian system of measurement was a valid response to the peculiar features of that country's coast. Even before the dispute with the UK, this method of measurement had been consolidated by a constant and sufficiently long practice. The fact that no government, including that of the UK, had ever protested indicated that they did not consider the Norwegian practice to be contrary to IL.

The Consensual Theory (Regionalism)

Can the opposition of a single state prevent the formation of a custom? How large must the majority be? Should factors such as population/political/military/economic power be taken into consideration? If some states are more important than others are, what makes them more important?

In the Lotus Case, the PCIJ also established consensus (i.e., regionalism) as the basis of customs. This is the Consensual Theory, which suggests that customs are only binding on states that have agreed to them out of their own free will. From the perspective of this Consensual Theory, the only difference between a custom and a treaty is one of form not of content: A treaty represents an express/explicit agreement and a custom represents an implied agreement.

Thus, just as different treaties can be in force between different groups of states, different customary rules can also apply between different groups of states. For example, Latin American countries claimed the 200-mile exclusive economic zone (EEZ) set down in the 1982 Law of the Sea Convention. Although the Convention did not come into effect until 1996, countries in the Latin America region that recognized this as a legal right complied with and recognized this claim, thus creating a new custom. The USA, however, did not accept the terms of the Law of the Sea and refused to recognize the validity of the 200-mile EEZ. As a result, the USA was under no legal obligation to respect other nation's claims. The USA encouraged US tuna fishing vessels to fish in the 200-mile zones of Latin American countries. If any US fishing vessels were apprehended, the US not only reimbursed them for the loss of their boats, but also deducted the amount from the foreign aid it provided to the country involved.

Given these problems with custom, more attempts have been made to codify custom in treaties. Examples include the second UN Convention of the Law of the Sea (Geneva 1959); the Conventions on Diplomatic Relations (Vienna, 1961 & 1963); Conventions on the Law of Treaties (Vienna, 1969 & 1986); and Conventions on state Succession (Vienna, 1978 & 1983). The International Law Commission (ILC) comprised of international lawyers under the authority of the UN General Assembly does the background work on codification.

According to Ian Brownlie, the four key factors in determining whether a custom exists include:

a. duration or passage of time,

b. substantial uniformity or consistency of usage by the affected nations (usus),

c. generality of the practice or degree of abstention, and

d. international consensus about, and recognition of, the particular custom as binding (opinio juris). 13

General Principles of Law

General principles of law, the third major source of international law, are subject to two interpretations. First, general principles refer to principles of domestic jurisprudence applied to international legal issues. Examples include the principles that presume the innocence of an accused person, and grant him/her the right to a fair trial.

In the second interpretation, general principles refer to the transformation of broad moral principles supposedly applicable to all humanity into specific rules of international law. This second and more controversial view is based on the idea that a  natural law (naturalism) or higher morality exists in addition to (or above) the  positive law  (or legal positivism) created by human beings.  14

Natural law emphasizes "what ought to be" – discovering and applying what is morally correct, just and fair. Positive law, by contrast, emphasizes "what is" and considers laws made by human discretion and action to be the only relevant laws. Although law may serve the cause of justice, achieving justice in all instances is not the focus of law. Legal positivists thus emphasize authority and order over justice; the central issue is not what is morally right, but what is feasible (i.e., enforceable), in society. 15

Positive law currently predominates in international law (and in most domestic legal systems). Most norms and rules in international law (treaties and customs) are derived from actual state conduct. However, the influence of general principles based on natural law notions is evident in the peremptory norms (jus cogens) discussed above.

Subsidiary Sources of International law

In addition to the three primary sources (Treaties, Customs and General Principles), there are two subsidiary sources of international law: judicial decisions and the opinions of legal experts.

Judicial Decisions

Judicial decisions form a subsidiary source of international law. International courts and tribunals, such as the ICJ, do not really make international law. They may interpret a rule, apply it, or through their rulings, eliminate an obsolete rule. Unlike domestic legal systems, precedents (i.e., previous court decisions on similar cases) are not as important in shaping the law. Indeed, the statute of the ICJ specifically rejects basing decisions upon precedents.

As noted in unit 1, the bulk of adjudication in international law occurs in the domestic courts of states. These domestic courts may make rulings on issues of international law, and their decisions may reflect the decisions of other courts as to the meaning/existence of a rule. Their decisions may also indicate what the rule is held to mean in the country in question at the time the decision is drafted, for example, the US Supreme Court ruling on the Scotia Case in text box 1).

Writings of Publicists

The writings of private legal commentators (scholars, lawyers, etc) represent a definitely subsidiary source if international law. These writings are used largely to determine varying interpretations of the law, or to provide assistance in the further development of law. In the early period of international law's development, however, the "classical writers" had greater influence in developing legal philosophies that were incorporated into state practices. Unit 3 examines the views of these classical writers.

Soft International Law

In addition to the 'hard' international law sources outlined above, international institutions such as Intergovernmental Organizations (IGOs), and informal agreements between states are sources of 'soft' international law. 16  Soft laws normally do not create binding obligations, and are expressed in resolutions, declarations, and informal agreements. However, although we can distinguish between hard and soft law, there is good reason to question the relevance of this distinction. 17

Hard international law is supposed to be binding whereas soft law is not, but this distinction is not clear-cut in practice, because even though soft laws may not be binding in a strict sense, states and other international actors habitually comply with it. 18  In contemporary international organization, soft law is often preferred for developing cooperative arrangements and elaborating rules and policies to manage international relations, because it has many of the advantages of hard law and avoids many of the disadvantages, particularly the amount of time it takes to make hard law. 19

For example, treaty making as a source of hard law requires ratifications that can cause major delays in implementation. The third UN Convention on the Law of the Sea (UNCLOS III) took nine years to negotiate (1973-1982) and did not come into effect until 1994, when the required sixtieth instrument of ratification was registered. The ratification process tends to postpone the effective date of treaties from two to twelve years after a formal agreement is adopted, with an average of five years. 20

IGOs and public international regimes are part of international law, because they make law, impart organization and structure to rules, monitor compliance with rules, and in some cases adjudicate and implement these rules. Furthermore, some commentators, especially from the Global South, argue that UN General Assembly (UNGA) resolutions are important sources of international law. 21 The traditional view is that UNGA resolutions are non-binding soft laws except when they embody existing customs or treaty rules. However, developing countries with their numerical superiority have challenged this view, because they look to the UNGA as the main vehicle for promoting their values and interests; and they use two arguments to support their position. First, much international law reflects a Western (Eurocentric) bias, because it is based on customs and treaties that were made when most developing countries were European colonies. Second, the UNGA is the UN's main representative and deliberative organ with almost universal state membership. Hence, its resolutions should be taken as authoritative evidence of what most states consider to be international law. 22 To date, there is no consensus on this issue.

The Hierarchy of Sources

The hierarchy of sources refers to the ranking of the various 'hard' sources of international law according to their importance. The key question is what happens when a rule of law derived from one source (e.g., a treaty) conflicts with a rule of law derived from another source (e.g., a custom). The answer is not clear-cut.

The following are some key guidelines on the relationship between treaties and customs:

1. International law differentiates universal or general international law, which binds all states, regional international law, which applies only to states in a particular region, and particular (or bilateral) international law that applies to the two states that ratify a treaty. These sources are hierarchical with general international law taking precedence over regional and particular law; and regional international law taking precedence over particular law.

2. Regional and particular international law may modify universal international law for states that are party to limited membership customs or treaties; but regional or particular rules do not relieve them from their general international law obligations. For example, a general rule of diplomatic immunity prohibits all states from prosecuting foreign diplomatic representatives in their territories. However, two states may sign a treaty permitting each state to prosecute the other's diplomats for crimes committed on its territory. While these two states may prosecute each other's diplomats, they cannot prosecute diplomats of states that are not parties to the bilateral treaty.

3. Normally, a treaty, when it first comes into effect, overrides a custom between the parties to the treaty. However, through desuetude (where one or more parties consistently ignore a treaty and the others do not object) a treaty can end. When this occurs, a new custom may emerge. Thus, treaties and customs are of equal importance; customary rules prevail, however, over time.

4. Although a treaty normally binds only ratifying states, it may also bind other states if its provisions codify a general international custom. If a treaty codifies a custom or is declaratory of it, it can be cited even against states not party to the treaty.

5. A legislative treaty that creates new rules may also become part of general international law if its provisions achieve the status ofopinio juris (i.e., obligatory rules). For example, the UN Charter codifies customs and creates new rules that bind all states, even non-UN members. The UN Charter is the single most authoritative document in contemporary international law.

6. Customs can sometimes be inferred from treaties but this is not always the case because why the need for a treaty in first place? Customs may change to conform to an earlier treaty.

7. Is a state fails to ratify a treaty its provisions will not be binding except where general customs are embodied in the treaty. Thus customs are binding even if no ratification occu