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This article is written by Antra Shourya from the Faculty of Law, University of Delhi. This article explains the obligations and rights enjoyed by third parties in a treaty and it further discusses how international treaties create objective regimes.


International law is more dynamic today than ever, and one of the most important sources of international law is treaties. Treaties play a significant role in international law, they create the bases of all international diplomacy. We often hear that how a particular move by a particular country is a violation of an international treaty or convention hence a violation of the international law. International law is a codified law and has been developed by many international treaties, some of which were pursued and brokered by the International Law Commission, which was established by the United Nations General Assembly (UNGA) in 1947 to develop and codify the international law. The International Law Commission’s continuous efforts and diplomacy led to the adoption of the Vienna Convention on Law Treaties (VCLT) on 23rd May 1969. The Vienna Convention came into force on 27th January 1980. India is not a signatory member of the convention but nevertheless is guided by it. Vienna convention on the law of treaties recognizes the importance of treaties as a source of international law, which makes it important to understand what is the scope and dynamics of a treaty, who can be parties to a treaty and who cannot be.

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General principles of a treaty

Article 1 of Vienna Convention on Law of Treaties, says that the convention applies to treaties between states and treaties between international organizations. The convention defines a treaty as “an international agreement concluded between States in written form and governed by international law, whether embodied in a single instrument or in two or more related instruments and whatever its particular designation.” Further Article 2 of the convention defines “Third State” as State not a party to the treaty. According to the definitions laid down by the Vienna Convention, a “treaty” means an international agreement concluded between States in written form and governed by international law, whether embodied in a single instrument or two or more related instruments and whatever it’s a particular designation. The word ‘treaty’ covers all forms of international agreements in writing between the states. The convention also covers other subjects of international law such as international organizations, Article 3 covers agreements between states as between themselves and under international agreements to which other subjects of international law are also a party. The general principles of international law with regard to treaties and conventions is that they create rights and obligations to states parties to them through ratification, accession, acceptance or approval, but there are exceptions to rule and sometimes third states also have obligations and rights under a treaty.

Article 34 of the Vienna Convention on Law of Treaties 

Pacta terries nec nocent prount, is a Latin maxim meaning that agreements neither impose obligations nor confer rights on the third state. A treaty primarily binds the parties to it, the principle behind it being that the rights and obligations should only be imposed on the parties who have consented to the rules or conditions. No state is bound by a rule of law unless it has expressly or impliedly assented to it. Article 34 of the Vienna Convention states that “A treaty does not create either obligations or rights for a third State without its consent.” According to the principle laid down in article 34, a treaty is a non-existent piece for third States, a res inter alios acta meaning “a thing done between others does not harm or benefit others” so a treaty can create neither obligations nor rights for third States, which also brings out the contractual nature of treaties.

Obligations and Rights of Third States

Obligations of Third States

The principle of Pacta Tertis Nec Nocent Nec Crosent i.e a treaty cannot create rights or obligations for a third party without its consent is expressed in  Article 35 of Vienna convention that states that “An obligation arises for a third State from the provision of treaty if the parties to the treaty intend the provision to be means of establishing the obligation and the third State expressly accepts that obligation in writing.” 

The two important elements of this article are:

  • Firstly, the third parties are consenting to a specific provision of the treaty and not the entire treaty;
  • Secondly, the consent has to be expressed in writing. This means that for a State to be bound by an obligation under a treaty to which it is not a party, it must consent to that obligation orally or in writing. 

Sometimes, such an expressed consent directed towards the parties to the treaty leads to the conclusion of a separate agreement between them. Article 35 makes it clear that the third party cannot be part of a treaty without their consent. This principle comes from the basic principle of international law of sovereignty, equality and non-interference. Article 34 of the Vienna Convention on Law of Treaties is not drafted in absolute terms. Article 35 of VCLT is based on the principle of consent that a treaty can rise to rights and obligations for a third state but only when the third state has consented to it. According to Article 35, the obligation is created on the third states in two situations namely, first when the parties to the treaties want to establish an obligation for a state not a party to the treaty, and second when the third parties themselves agree to be bound by a treaty.

Exceptions to Obligations of Third States

The general rule of the obligation laid down in Article 35 of VCLT does not apply in certain cases. Article 75 of the UN charter states that an obligation for a third State arises from a provision in a treaty only with its consent would not apply to the case of an aggressor state. Another important exception to the rule expressed in Article 35, that a third State must accept in writing the obligation sought to be imposed upon it by the treaty is contained in Article 2 paragraph 6, of the United Nations Charter which provides that the Organisation shall ensure that states which are not members of the United Nations act in accordance with the principles of UN Charter insofar as may be necessary for the maintenance of international peace and security. This obligation of the third States was confirmed in Namibia case where International Court of Justice held: “As to non- member States, although not bound by Article 24 and 25 of the Charter, they have been called upon in para 2 and para 5 of the resolution 1976 (1970) to give assistance in the action which has been taken by the United Nations with regard to Namibia. 

Rights of Third States 

The rule laid down in Article 36  of VCLT is that “A right arises for a third State from a provision of a treaty if the parties to the treaty intend the provision to accord that right either to the third State, or to a group of States to which it belongs, or to all States, and the third State assents thereto. Its assent shall be presumed so long as the contrary is not indicated unless the treaty otherwise provides.” It further states that a State or an international organization exercising a right in accordance with the above-mentioned provision shall comply with the conditions for its exercise provided for in the treaty or established in conformity with the treaty. The conditions that need to fulfilled to give rights to third parties under a treaty are: firstly that the treaty intends to give rights to the third states, and secondly, the third states consent to the rights give, thirdly, the consent of the third states shall be taken for granted unless it expresses otherwise, and lastly, if the treaty demand that the third state should express it’s approval in a particular way, the consent would only be effective when it is expressed in that particular way. The assent may be presumed on certain aspects, if the treaty doesn’t exclusively talk about these aspects, provided there is no evidence to the contrary.

Revocation or Modification of Obligations or Rights 

The revocation or modification of obligations or rights arising from third states from the provisions of a treaty is covered by Article 37 of the VCLT. Article 37 draws a distinction between obligations and rights. As regard to obligations, the rule is that the obligation may be revoked or modified only with the consent of the parties to the treaty and the third state. As regard to revocation or modification of rights, the rule is that a right which arises for third states may not be revoked or modified by the parties if it is established that the right was intended not to be revocable or subject to modification without the consent of the third state.

International Customary Law as an exception

Article 38 of the VCLT says that “Nothing in Article 34 to 37 precludes a rule set forth in a treaty from becoming binding upon a third party as a customary rule of international law, recognised as such”, which means rules in a treaty which are customary laws may become binding on the third States. Rules and principles laid down in treaty, that has been concluded between two parties, may become generally acceptable by third states and become binding on them by the way of custom. The Hague Conventions on the rules of land warfare were held by the International Military Tribunal at Nuremberg to enunciate rules which had become generally binding rules of customary law. A treaty might contain rules which are customary rules at the time of their formulation in the treaty. Such rules bind the third States, in their status of customary norms of international law and not as conventional norms. Being customary norms, these impose customary obligations on the states. The International court of justice in North Sea Continental Shelf case of 1969 held that for rules of a treaty to become international customary law, that provision of the treaty has to fulfill three conditions:
1. The norm should have the character of becoming a general rule, i.e it should have a universal character.
2. It can pass into the general corpus of international law.
3. It should be accepted by opinio juris i.e. accepted as a general practice and an accepted law. 

Treaties and Objective regimes

What are objective regimes?

There are certain treaties that establish freedom of navigation in international rivers and in maritime waterways; treaties that provide for neutralization or demilitarisation of particular territories or the Antarctic Treaty. These treaties come under a special category of so-called “objective regimes. In many cases where rights of third parties have been derived from a treaty such as in case of establishment of international canals such as the Panama Canal and in Wimbledon case, demilitarisation of certain areas, for example, Aland Island Case or the various peace treaties are also classical cases of objective regimes. The issue of the legal status of so-called objective regimes is related to the issue of the effects of treaties on the third State. Often these issues are viewed together without any doctrinal separation as seen in many cases objective regimes are created by treaties. McNair dwells on this issue in-depth in his Law of Treaties.

Do treaties create objective regimes?

Lord McNair in his book, The Law of Treaties, separate these issue of objective regimes and treaties effects on third states. He analyzed the effect of treaties on third parties within the scope of operation of treaties, as an exception from the general rule pacta tertiis nee nocent nee prosunt, whilst the theoretical and practical problems relating to objective regimes and their effect erga omnes i.e towards all, on a certain type of treaties. But even McNair, who strictly separated the two regimes, observed that the possibility of a theoretical and practical overlap between them, as illustrated by the Free Zones Case. Another writer, however, Arechaga, in his important article “Treaty Stipulations in Favour of Third States”, did not draw any doctrinal distinction between treaties which are in favor of third states and treaties which purport to set up objective regimes. McNair further in his book the Law of Treaties describes types of treaties that create objective regimes, dispositive treaties, and constitutive treaties. 

Dispositive Treaties

Dispositive treaties are those treaties that deal with the management of territories and inherent rights within a territory. An example of a dispositive treaty would be the mandate giving power to South Africa to govern over Namibia. A dispositive character is the nature of the rights that they establish. The treaties of this category create or transfer or recognize the existence of certain permanent rights, which acquire or retain an existence and validity independent of treaties that created or transferred them. This category of treaties generates a type of rights for individuals that are different from the rights acquired under the other general type of treaty. These rights are not in their origin necessarily rights in rem but are like them due to the fact that they are characterized by an objective existence that enables them to survive even when the treaty which generated them became extinct.

Constitutive Treaties 

Constitutive treaties are those treaties which establish a specific regime for the specific geographical area or create a new entity like a state or an international organization. According to Mc Nair, the type of treaty entered into by only certain groups of states, which create an international organization which is endowed with an objective international personality valid erga omnes and effective not only vis-a-vis the states which establishes it but all other states would appear to belong to the category of constitutive or semi legislative treaties. These treaties have a public law character and embody the decisions of a power group of states acting or assuming to act in the public interest. McNair gave examples of the United Nations or of the League of Nations. International political-economic organizations like the European Union, North Atlantic Treaty Organization( NATO), also have characteristics of a constructive treaty.

Vienna Convention on Law of Treaties 1969 and Objective regimes

The Vienna convention leaves objective regimes as the ICL felt that the provisions under Article 36 and 38 provide satisfactory mechanisms to explain the legal nature of objective regimes, in a particular alleged automatic objective effect of certain types of treaties. Situations, where objective regimes are created by treaties, are very limited under the Vienna treaty on the Law of Treaties. Article 36 covers situations, like in the case of, the regimes of Turkish Straits or of the Kiel Canal that exemplify a general category of treaties providing for an establishment of land or maritime territory utilization by third states and may be said to create automatic legal effects in relation to third states (effective without any express agreement). These regimes are mostly aimed at the establishment of rights and are accompanied by the exercise of certain obligations by third states as a condition for exercising these rights.
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Case Studies

Free Zone Case

In 1932, the Permanent Court of International Justice (PCIJ) gave the judgment of conflict between Switzerland and France over a territorial dispute. In Free Zone Case, Switzerland, a third party, enjoyed since 1815 the benefit of a free customs zone in Upper Savoy and Gex district of France in accordance with a stipulation made in her favor by certain multipartite treaties to which France was a party. Switzerland, though not a party, accepted those benefits. According to Article 435 of the Treaty of Versailles free zone were inconsistent with rules of treaty and France and Switzerland had to come to an agreement with regard to the free zones. France wanted to abolish the free zones. The matter was to be settled in the court of PCIJ. The court did not abolish the free zones and held that Switzerland was not a party to the Treaty of Versailles hence it can’t be bound by the same. The creation of the free zone form part of an agreement to which France was party to with other states, which was in favor of Switzerland. The agreement made a stipulation in favor of Switzerland. It was held that she could not be deprived of that right without her consent.

Panama Canal Case

Hay-Pauncefote Treaty 1901

The treaties governing the Panama Canal give third states the right of usage of the canal under the condition of conforming to rules governing the Canal, taking this interpretation of the treaties, we can say in case of Panama canal Article 36 para 1 and para 2 of VCLT are applicable. The Hay-Pauncefote Treaty was concluded between the United States of America and the United Kingdom, it was clear in the treaty that both the countries were unwilling to give or provide any rights to the third states. Although the treaty didn’t have any adherence provision it did state that the canal shall remain open and free to all vessels observing the rules laid down by the treaty. The Panama Treaty signed between the United States and Panama in 1977 established a framework for the operation of the canal until 31 December 1999.

Panama Treaty 1977

The Panama Treaty of 1977 abrogated the 1901 Treaty, and gave Panama Sovereignty over the canal, and also gave the United States the right to manage, operate, maintain, improve, protect and defend the canal until the year 2000. The second treaty was the Treaty concerning the Permanent Neutrality and Operation of the Panama Canal. Article 1 of the treaty declared that “the Canal, as an international waterway, shall be permanently neutral in accordance with the regime established in this Treaty. The treaty required all the vessels to adhere to the rules and regulations laid down by the treaty, further after 2000, the treaty gave the republic of Panama exclusive rights over the operation of the canal. Article 7 of the treaty proposes that the United States and Panama “shall jointly sponsor a resolution in the organization of American States opening to accession by all States of the world the Protocol to this Treaty whereby all the signatories will adhere to the objectives of this treaty, agreeing to respect the regime of neutrality set forth herein.” This Protocol is open to accession by an international community to recognize as widely as possible neutrality of the Canal. It may be observed that there were no reactions from third states as to the neutrality treaty and the Protocol.

Treaties like the Panama Treaty and Suez Canal Treaty try to establish a legal framework where rights can be given to third states as regards to the use of the canal but the United States in relation to the legal status of the Panama Canal denied rights to the third parties. Neither the character (procedural and substantive) nor the scope of these rights for third states nor the locus standi in the event of their breach is precisely defined. It may even be that these entitlements for third states are not rights but benefits only, and such an interpretation would further limit the possibility of any claims from thirds States in relation to the breach of a condition of the use of, or denial of, access to the canals in question.

Wimbledon Case

Facts of the case 

The Wimbledon Case was regarding the legal status of the Kiel Canal. The Kiel canal passes through Germany and links the Baltic and North Seas. The legal status of the canal was settled in 1919 by the Treaty of Versailles (Article 380-386) which made the canal open to all parties to the treaty. Article380 made canal free and open to vessels of commerce and of the war of all nations at peace with Germany and on terms of entire equality. During the 1920 Polish – Russian war an English ship, authorized by French shippers, was banned from accessing the Kiel canal by the Government of Germany, the ship was carrying munitions for the Polish Government. The German Government took the ground that if it allowed the passage of said ship it would be a breach of Germany’s neutrality in the war. A case was brought against Germany by all the states party to the Treaty of Versailles.

Court’s Decision

The Permanent Court of International Justice held in this case that Germany was bound by Article 380 of Treaty of Versailles, it was obliged by the virtue of Article 380 to allow passage of all vessels until their passage is a violation of this article. Since Russia was not a party to the Treaty of Versailles, the court rejected Germany’s grounds of neutrality in the war. The court also said that Germany could take the legal ground of neutrality in war for not performing its obligations as a neutral state and that Russia and Germany were bound by general customary law on neutrality further the court said that the passage of warships and war materials, through canals did not compromise the neutrality of the states which had territorial sovereignty or jurisdiction over them.

Legal Status of Kiel Canal

On the question of the legal status of the Kiel Canal, the court established it as a “new regime” under the Treaty of Versailles, which was to be applied objectively for international navigation. But the Court did not define the nature of passage through the Kiel canal for third parties whether it is a right or a benefit. Making it a right would give third states a locus standi before international courts and tribunals. In conclusion, it may be said that the Court has admitted the existence of a certain “objective and permanent” regime of the Kiel Canal based on a treaty, without a strict definition, as to the nature of rights (if any) deriving from this regime for third states.


  • The Vienna Convention on Law of treaties 1969 lays down important provisions in regard to the position of third States in a treaty. The basic principle laid down in the VCLT is that the treaties are only applicable to the third states when they have consented to it. The Convention upheld the general principle of sovereignty of the states and gives rights or obligations to states only when they have consented to it.
  • Treaties establishing objective regimes and are erga omnes like treaties establishing freedom of navigation in international rivers and maritime waterways are applicable to third parties if they have consented to certain provisions of the treaty it is not necessary that they consent to the whole treaty.
  • Rights can only be conferred to the third states when there is an intention for the same; sometimes rights confer on their own, or rights may be conferred with a duty to exercise a certain obligation.
  • There are exceptions to the rules of an obligation under Article 35 of VCLT like the obligations imposed by the United Nations Charter for international peace and stability.
  • A treaty creates rights or obligations for a third state under two situations namely, firstly when the states parties to the treaties intended to create such rights or obligations, and secondly the third consent to such rights or obligations. Rights of the third states can only be revoked or modified only when the treaty specifies that the rights given were revocable, and the third parties have consented to it. 
  • Third parties have to adhere to the provisions or obligations of a treaty if the provisions of the treaties are customary international law.


  7. Third States and Law of Treaties, Malgosia Fitzmaurice
  8. International Law, Second edition, Gurpid Singh

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