Consent plays a pivotal role in the development of international law. It can be used as an instrument of protecting the sovereign equality of nations and jealously guard one’s interest (Guzman, 2011). Given the heterogeneous interest of nations, however, it can also be an impediment for the development of international rules (Guzman, 2011). Positive law theorists emphasized that a state must give its consent to be effectively bound by the international law, but the naturalists support the idea that international law can exist without the will of the nations (D’Amato, 2010). State consent has the potential to increasing compliance of nations with international laws and bolster legitimacy or/and constituency, and help to tackle frequent, or rather haphazard deviation from the international obligations.

Though there is no direct reference of ‘source’, the generally recognised authoritative statement where international laws fountain from is the Statute of the International Court of Justice. It would be pertinent to single out and discuss each source of international law that are enshrined under Article 38 Paragraph (1) of the Statute to scrutinise whether the concept of consent is fake in the realm of international law. There are live debates whether or not certain conducts, like a unilateral declaration of governments and Resolution passed by the General Assembly, constitute sources of international law and has a normative effect. This piece, however, stepping aside these discourses, try to limit its focus on sources of international law envisaged by Article 38 of the ICJ Statute.

1. International Conventions, Whether General or Particular, Establishing Rules Expressly Recognised by the Contesting States

Treaties are principally dependent on the consent of the Contracting Parties, and they cannot give rights and impose obligations on third states (pacta tertlis nec nocent nec prosunt). But there are some exceptions to the rule pacta sunt servanda. Firstly, when the intention of the State Parties is to accord right(s) to or impose obligations on a third party, and if the latter accepts the treaty, the agreement will be binding on the third state. Secondly, Treaties that declare the crystallised international customary law are applicable to the non-state parties, too. But the non-parties are subject to the rule not because of the treaty but the customary rules (Shearer, 2014). Thirdly, ‘multilateral treaties creating new rules of international law may bind non-parties […] or de facto applied to them as standard setting instrument’ (Shearer, 2014, p. 406) and the application of certain multilateral conventions may extend to non-parties. (Treaties that create erga omnes may bound third states and The application of the Geneva Drug Convention (1931) which is replaced by the Single Convention on Narcotic Drugs (1975) as amended in 1975, extends to non-State Parties) (Shearer, 2014). Fourthly, non-signatory states may be bound by the agreement if the treaty is ‘establishing a special international regime and an international organisation.’ (Wallace, 2002) Even though, Wallace (2002) argues that Article 2 Paragraph (6) of the United Nations Charter binds a non-member state, that is not the case, rather this provision dictates the UN to persuade non-member states to act in accordance with the principles that are fleshed out in the Charter. 

In relation to the first two scenarios, the consent of the state is vital, but in the latter two, states may fall under the jurisdiction of an agreement without their will. 

The unilateral statement that meant to exclude or modify the legal effect of a certain specific provision of a treaty—Reservation, is a caveat to states to be part of a treaty system and insulate its interests. Reservation is an epitomise of the manifestation of the role of state consent while crafting an international law. 

2. International Custom, As Evidence of a General Practice Accepted As Law

The establishment of customary international laws involves three activities of states. A State can (1) freely subject itself to the customary rule (consent), (2) can keep silent (acquiescence) or (3) consistently object the application of the rule. As the manifestation of state sovereignty, nations can give recognition for the application of customary rules. One of the scenarios that scholars agree upon in relation to the development of customary international law is acquiescence-state’s silence. This silence may be interpreted as implied acceptance, or being indifferent towards the issue (Crawford, 2012). A state can be bound by the crystallised international customary rule albeit it has not expressed its consent as long as the rule fulfils the opinion juris and ‘state practice’ requirements. The binding force of the customary rule, in acquiescence, emanates from the silence of the state (implicit consent) and it may not be opposable to that state. The purpose of interpretation of silence as acceptance is the difficulty of proving consent (Wallace, 2002). But consent would be difficult only if the state keeps silent. If it protest or accept the rule, it would not be difficult to infer the intention. However, I opined that even the silence should not be interpreted as an acceptance.

The silence, however, should not amount to acceptance, but if so, the rule becomes a binding law without the explicit approval of the state and makes the positivist concept of consent futile.

Despite the existence of International customary law, a state cannot be bound by it if it has been contesting the application of the rule since its inception. This idea is more fortified when ICJ expressly underpinned it in the Anglo Norwegian Fisheries case: ‘…the ten-mile rule would appear to be inapplicable as against Norway inasmuch as she has always opposed any attempt to apply it to the Norwegian coast.’ 

The dissention shall be made during the whole life of the customary rule and if it is abandoned at a certain point of time, the protest will remain without a tooth. Therefore, ‘…the persistent objection rule reinforces the principles of state consent in the creation of custom’ (Crawford, 2012). In the majority of the cases, the persistent objection is considered as an expression of intention not to be bound by the newly emerging customary rule. But some scholars are trying to annul the concept of consent even from the realm of customary rule formation.

‘…custom at present no longer maintain its original ‘consensual features’. This proposition can be advanced on two grounds. First, no one could deny the current community-oriented configuration of international relations (which are much less individualistic, and more social values oriented). At present, it is extremely difficult for an individual state to eschew the strong pressure of the vast majority of members of the community. Second, there is no firm support in state practice and international case law for a rule on ‘persistent objector’. The only explicit contention in favour of this contention is set out in two obiter dicta of the ICJ (in Asylum and Fisheries) and in the pleadings of the UK and Norway in fisheries.’ If the rule is a matter created for the common goods (e.g. for climate change and preservation of fish stock) states can even be bound by the customary rule if they oppose let alone in acquiescence.

Despite the lack of consistent case law, it is generally accepted that the state can relieve itself from the customary rule obligations if it persistently protests against the rule from the outset (Evans , 2014). Had it not been for the persistent objection principle, customary international law would have been ‘created by the majority and imposed willy-nilly on the minority’(Evans, 2014, p.103).

Any newly established state, whether agrees this or not, is bound by the duly established customary international law (Evans, 2014, Wallace, 2002, Cassese, 2005). This idea also makes the concept of free will that is enshrined in the preamble of Vienna Convention on the Law of Treaties unavailing. It dictates the adherence of states to the international norm created without their participation and will. The new state, however, should get an opportunity to express its feeling to accept, acquiesce or persistently object the customary rule (Shaw, 2008).

Consent is not the basis of the binding force of customary international law for newly created states and for those who keep silent towards the development of the new customary rule. I opined that the newly created state should get the chance of expressing their feeling than making all customary rules binding by default. Acquiescence may amounts to tacit consensual acceptance of the customary rule.

3. The General Principles of Law Recognised By Civilized Nation

Article 38 Paragraph (1) (C) of the ICJ Statute authorizes the court to borrow some international and national precepts from the developed legal systems when non-liquet situation happens (Crawford, 2012). ICJ can infer some principles from the advanced legal systems of the world. If a certain principle is deduced from a legal system that a state belongs to and analogized to solve a problem to which the state is a party, it might be possible to conclude that the concerned state has consented for the principle. But, what if the principle is not recognized in the domestic legal system, but ICJ utilised to solve the puzzle that the state is a party? Obviously, the state is not consented to the application of that principle. So, for the principles that are found in all legal systems, it is safe to conclude that all nations have given their consent. However, if the principle is not recognised by the domestic legal system of the state in contention, the states are not assented to be bound. 

4. Judicial Decisions and the Teachings of the Most Highly Qualified Publicists of The Various Nations

As inferred from the word ‘subsidiary’ in Article 38 Paragraph (1) (D) of ICJ statute, judicial decisions are not an actual source of international law, rather helping to prop up the court’s decisions (Shaw, 2008). The decision of the court is only binding between the parties and applicable only in respect of the particular dispute. Not only the decision of ICJ and its predecessor, the Permanent Court of International Justice, but also verdicts passed by national courts and other international tribunals can also be considered by the court (Shaw, 2008). The states can cite decisions of court(s) while presenting their case before the court. If the court applies the decision cited by the parties or verdicts passed by their national courts, to solve any bone of contention, it can be considered that the states are consented to be bound by the rule of interpretation or the principles that they cited or applied in their domestic courts. Nevertheless, the court can also apply decision by its own initiation and it can utilize principles developed by another state’s court. In this case, the state is not assented to be subjected by the principles which are developed by domestic courts and later borrowed by the ICJ.

Academic writings play a pivotal role in the development of the international rules by ‘stimulating thoughts… pointing out the defects… and making suggestions as to the future’ (Shaw, 2008, p.113). With similar note, it can be possible to say that states have consented to a certain way of argument or interpretation of rules if they cite a specific writing, as an authority, in their claim or defence. The court’s application of rules and writings by its own motion does not necessary make states to subscribe for that reasoning or way of looking.

It seems possible to say that states have consented for any agreement, reasoning, and norms that are applied by the court when they accept the contentious jurisdiction of the court. However, this line of argument will not be promising because if that is so, the court could also apply any treaty that state parties are not a signatory. This is manifestly against the sovereignty of states (even against the limited sovereignty principle) and contrary to the principle that the international norm built up on.

Generally, though consent has some places in Article 38 Paragraph (1) of ICJ Statute (treaty, persistent objector), it is not as strong as it imagined being the basis of international law. A cursory glance at the article, together with the court’s practice, exposes the weakness of the role of consent in the contemporary development of international norms, but does not by any means signify that consent is irrelevant.

By Henok Abebe Gebeyehu