Treaties have been around as a concept of international law, since the dawn
of time. One of the earliest instances of treaties can be traced back to 2100
BC, wherein an agreement was entered into between the kings of the cities of
Umma and Lagash in Iraq. Through the treaty, they established a specified
boundary between the two cities by inscribing the terms on a stone block.
Thus, treaties have always held a prominent place in international law. They are
considered as a means to ensure peaceful and amicable relations between
different countries by helping international organizations organize, regulate
and oversee their affairs. During the earlier days, treaties were mostly
contracted through oral means and they were concluded with a ritual in which the
participants swore an oath to God, which served as the treaty's binding force.
Since then, its undergone notable changes, the process of concluding treaties
became more organized and streamlined, consequently the treaties that are
entered into these days, between countries, require to be in writing. It is also
considered as legally enforceable.
Treaties essentially refer to contracts between nations. The primary purpose of
creating a treaty is to establish legal relationships between parties in order
to govern their relationship through a contract. The nature of the Treaty
device, which provides for the rights and obligations of parties constituting
part of the treaties, governs the majority of conduct between nations.
These agreements can be in the form of an extradition agreement or a defense
pact. It can also be in the nature of a law that governs specific aspects of
foreign relations or serve as the foundation for international organizations.
Law making treaties may be those creating universal rules such as the UN charter
or they could also be specifying general rules such as the Vienna Convention on
the law of treaties. A contractual treaty on the other hand deals with specific
issues affecting two or more states.
Conventions, pacts, charters, statutes, declarations, covenants, and agreements
are all examples of international agreements that are referred to as "treaties."
Vienna Convention On The Law Of Treaties
The Vienna Convention on the Law of Treaties (VCLT) is the result of two
protracted sessions of the 110-nation conference and also of the 15 years of
preparatory work by the United Nations' International Law Commission (ILC). It
is the first key component that has been exercised in the daunting challenge of
codifying international law in accordance with Article 13 of the UN Charter,
and is undoubtedly considered to be the principal authority dealing with the
formation of treaties, drafted by the ILC and adopted on the 23rd of May, 1969.
According to the VCLT, treaty refers to an international agreement concluded in
writing between states regulated by international law, whether included in one
instrument or two or more linked instruments. 
This convention, also referred to as the "treaty on treaties" establishes a
system of rules that would control the crucial element in the conduct of
international relations. It addresses the most significant aspects of
international law regarding treaties entered into between different states.
Before the convention could take effect, it needed to be ratified by 35 UN
member nations which were obtained by the end of 1979. As of 2022, 116 countries
have ratified the VCLT.
The terms and scope of the agreement are dealt with in Part I of the convention.
The 2nd part lays down the procedures for concluding and adopting treaties,
emphasizing the importance of parties' consent to be bound by it and the
drafting of reservations. The third part essentially describes how the treaties
are be applied and interpreted.
The modification and amendment of treaties are dealt with under the fourth part.
Part five of the convention, which is the most essential part, sets out the
grounds for the "invalidity, termination, withdrawal and suspension" of
treaties, and the consequences for the same. Further it also contains a clause
which grants International Court of Justice (ICJ), the jurisdiction over
possible disputes arising over the applicability or interpretation of the
The remaining parts cover the impacts of modifications in governance within a
state, escalation of state-to- state conflicts, on treaties. It also specifies
the rules for signing and ratification.
Treaties As A Source Of International Law
The Binding force of treaties has been a source of major controversy. One
instance is the landmark ruling of ICJ in the Nottebohm case which triggered
arguments with respect to the citing of The Bancroft Treaties and the
Pan-American Convention of 1906 as the only precedents.
Those dissenting the judgement reasoned that the treaties in question were
bilateral treaties in which neither of the Nottebohm parties were involved. They
further argued that these treaties were only binding on the contracting parties
and thus will not have any bearing on the on the Nottebohm case. However, it is
to be noted that Treaties have the potential to set precedents in general
international law that would be binding even on non-signatories.
The general view is that treaties can be accepted as a source of law. The maxim
pacta tertiis nec nocent nec prosunt elucidates that if a norm is repeated in
a significant number of treaties, it becomes a customary law; similarly, when a
major multilateral convention has been in force for a long time, its rules get
incorporated into the customary international law.
It is to be noted that the idea of treaties as a source of law emerges from the
time-honored and enduring principle of Pact servanda. The preamble of the VCLT
clearly provides for clear rules stating that free consent and good faith are
universally acknowledged. Anzillotti, an Italian jurist seems to be of the view
that the binding power of treaty is established on the fundamental premise of
pacta sunct servanda.
"The norm pacta sunct servanda which constituted since time immemorial the axiom
postulate and categorical imperative of the science of international law", is
unquestionably a positive rule under the international law.  This principle
is what requires governments to obey treaties they have ratified, and it is the
bedrock of a just system that governs sovereign nations on an equal footing.
Further, in addition to general principles, treaties are also acknowledged as a
source of law in accordance with Article 38(1) of ICJ's statute. The term
"international conventions" referred to under this article focuses on treaties
as a source of contractual obligation, at the same time it also acknowledges
that a state may expressly accept the terms of a treaty to which It is not
technically a party. They are also generally referred to as persuasive law.
The controversy as to whether a treaty could be an ispo facto law or simply a
legal obligation is a separate issue. The evolution and history of usage of
treaties reveal that Treaties became more important when the world began to
settle into states. Treaties gained additional significance as a result of the
establishment of international organizations. Then followed the Law of Treaties,
which fully established treaties as a source of international law.
A treaty provision can also result in a rule of customary international law as
was observed in the case of North Sea Continental Shelf Case Further, the
case of Portugal v. India ( Right of Passage) exemplifies how a
long-standing treaty clause can assume the role of a custom. The case
demonstrates that when two States pursue a particular subject or practice
repeatedly for a long period, it becomes a binding rule. The case, in addition
to the asylum case established that local or regional custom that differs from
general customary law is only obligatory on States that support it.
A treaty is enforceable on each party's full territory unless the treaty
expressly provides for its limited application.
There are different modes by which the state may choose to be bound by a treaty,
the representative of the state may express its consent by the means of a
signature or by exchange of instruments forming a treaty for instance, the Rush-Bagot
treaty for mutual disarmament on the Great Lakes. The other ways by which a
state could express its consent could be by way of ratification, accession or by
any other mode if so agreed.
Formation Of Treaties
- Accrediting of plenipotentiary/representatives on behalf of
The first step involved in the formation of a treaty is to authorize certain
representatives, who will be granted the power by the Minister of foreign
affairs to represent the state for ratification, adoption, negotiation etc.
of a treaty.
- Negotiation & adoption of text
The persons accredited are authorized to enter into negotiations or
adoptions. This requires the agreement of all parties to the treaty. The
treaty is adopted after all concerning matters are resolved. If the adoption
is being done at an international conference, the acceptance of the text
will require a two-thirds majority unless otherwise negotiated or
The next step involved is signature by the accredited representatives once
the final draft of the treaty is prepared. The treaty thus comes into force
once it is signed by the authorized representatives on behalf of the
contracting states. It however becomes binding only after it is ratified by
the states in question which is the next step.
Ratification refers to the act of the parties to an international treaty
adopting it. It implies the conformation of a treaty signed by the
representatives of various states involved which is done by the head of the
state by conforming to the provisions of the constitution. A state can
declare its agreement to a treaty in a variety of ways. It can be expressed
through signature, ratification, accession or exchange of instruments.
Treaties can bind countries only if they consent to be bound by them and
thus this is a very important step in the creation of treaties.
However, ratification of a treaty may be withheld for the reasons listed
- If the representative has acted in excess of his or her authority
- If the representative has been subject to deception with respect to
the matters of fact.
- If it becomes difficult to fulfil the treaty requirements.
- In the absence of consensus ad-idem
A non-party state that wasn't an original signatory can become a party to
the treaty by accepting a treaty that has already been concluded. This is
referred to as accession. On the other hand, adhesion is when a third-party
state accepts or adheres to certain terms of a treaty that has already been
signed. Due to the thin line of difference, these terms are used
interchangeably. However, the distinction lies in the fact that in case of
accession, the non-signatory state accepts all of the provisions contained
in the treat, whereas in case of adhesion, the non-signatory accepts a few
but not all of the provisions.
- Coming into force
The next step is essentially the enforcement of treaty. This depends on the
provisions contained in a treaty. it may include a specific clause regarding
the date of applicability of the treaty. Further, certain treaties become
binding immediately after it has been signed, while others may come into
force only after it has been ratified by a prescribed number of states. A
fundamental premise of international law is that only those parties are
bound by a treaty that have consented to be bound by it, this is exemplified
by the maxim "pacta terties nec noncent nec prosunt."
Following ratification, the treaty must be registered with the International
Organization's headquarters. According to Article 102 of the UN Charter,
registration and publication is essential and if this requirement isn't
complied with then the treaty cannot be invoked before any organ of the UN
charter. This doesn't however mean that the treaty would become invalid or
be unenforceable. In addition to this provision, Article 18 of the
covenant on league mandates that every treaty must be registered with the
league secretariat and until it is so done, it won't be binding on any
state. This further implies that in the event of a dispute, a non-
registered treaty could not be relied upon.
- Enforcement & incorporation of treaties
The final step is the enforcement of treaties where the treaty is
incorporated into state law.
Interpretation Of Treaties
The term "interpretation" comes from the Latin word "interpretio," which means
"to translate the meaning of a sentence from an unfamiliar language into a
recognized one for the receiver." States Parties to the Treaty, international
organizations, and doctrinaires are all capable of interpreting treaties.
The primary rules with respect to interpretation of treaties is contained under
the 3rd part of VCLT, outlined in Articles 31 to 33 which can be summarized as
- Examining/analyzing the exact test of the treaty.
- The contracting parties' intention while negotiating.
- Consideration of purpose behind the formation of treaty.
Article 31(1) of the VCLT states that "treaty shall be interpreted in
accordance with good faith and in light of the ordinary meaning, object and
purpose." Thus, the main condition that needs to be satisfied while interpreting
is that the interpretation must be bona fide keeping in mind, the object behind
the formation of treaty.
Article 31(2) states that in addition to the text and preamble of treaty,
any agreement or instrument made in relation to the treaty shall also be
considered for the purposes of interpretation. Article 31(3) further
provides that any subsequent agreement concerning interpretation between
contracting states, or any other practice in application of general rules or
other rules of international law will also be considered. Sub section 4 also
stipulates that if the parties intended for a phrase to have a special meaning,
then it will be accorded that meaning.
"Travaux preparatories" and other supplemental ways of interpretation may be
applied if the text is ambiguous. While interpreting the treaties, adopting a
broader purpose approach is suggested. In circumstances where the treaty in
question involves the constitution of an international organization, a
purpose-oriented approach is usually taken.
Apart from this, there are certain general principles of interpretation
which can be summarized as follows:
The additional principles of interpretation as identified by
Fitzmaurice are as follows:
- Grammatical Interpretation
The words and phrases as contained in the treaty, are analyzed in terms of
their plain and actual meaning. This necessitates a legally binding
worldwide standard for the interpretation of grammar rules on syntax,
vocabulary and morphology.
- Object and content
If in case certain terms and phrases used in the treaty are uncertain and
vague, they are required to be interpreted in light of the treaty's overall
goal and context.
- Reasonable interpretation/ Logical interpretation
As mandated by the general law on treaties, the text must be interpreted in
a reasonable manner. This essentially refers to a strategy for clarifying
the content of a treaty through the application of logic, reasoning and
- Historical Interpretation
Teleological interpretation refers to interpreting the treaty by elucidating
the terms used in the light of historical, political and social
circumstances as well as the demands which led to the formation of the
instrument in question.
- Principle of effectiveness
The general principles also direct that the interpretation should be done in
such a manner so as to promote its usefulness and effectiveness.
- Reliance on extrinsic Material
Amidst a lot of controversy, the International Law Commission proposed that
extrinsic material be used to interpret the treaty. As a result, it was
decided that the treaty's preparatory work and the circumstances of its
conclusion could be used.
- Actuality/ Textuality
Treaties must be understood in their entirety and on the basis of their
- Natural & ordinary meaning
The principle of ordinary meaning can be deviated from only when the
original interpretation would lead to an irrational conclusion. Extraneous
means, like examining immediate circumstances or preparatory work involved,
commonly referred to as travaux priparatoires, may be employed only if the
language used is essentially unclear or ambiguous.
The interpretation can be done by considering the treaty as a whole as well
as by dividing the treaty into individual parts, chapters or sections.
- Effectiveness "ut res magis valeat quam pereat"
- Subsequent practice
The use of subsequent practice of the parties in connection to the treaty in
interpreting a text is acceptable, and may be desired.
The terms contained must be interpreted in accordance with the current
linguistic use of the terms.
In a case before ICJ, the ICJ stated that the tribunal's responsibility is
to examine the treaty's ordinary meaning. The ICJ has also observed that
interpretation is a judicial role and the main objective behind it is to
discover the precise and accurate meaning of a provision, and the same cannot be
modified. Analyzing the backdrop of a treaty's workings and its preparation
efforts (travaux pr'eparatoires) can aid in the treaty's interpretation.
It is also to be noted that when a treaty has been concluded in more than one
language, as is common with multilateral agreements and if there is a lack of
consensus, or in the event of a difference of meaning that cannot be resolved
through regular interpretation processes, Article 33 states that the meaning
that best reconciles the passages, taking into account the treaty's object and
purpose, shall be accepted.
Invalidity, Termination And Suspension Of A Treaty
The two primary ways by which a treaty can be terminated is by the operation of
law or by the act of contracting parties. Listed below are the different reasons
for which a treaty may be terminated by operation of law:
- Extinction of either contracting party
With reference to a bilateral treaty, extinction of either party may result
- Formation of a new treaty on the same subject matter
In such a case, it will be implied that the previous treaty stands
terminated, subject to the condition that states intend to be regulated by
the provisions of the new treaty or if both the treaties are of such nature
that their provisions cannot be applied simultaneously.
- Violation or breach of treaty
A party to the treaty may be entitled to terminate or suspend a bilateral
treaty in case of substantial or material breach by the other party. In the
case of a multilateral treaty, a unanimous decision may be taken as to
whether the treaty should be terminated or suspended either wholly or in
- Impossibility of performance
The inability to meet the treaty's terms is deemed sufficient cause for a
treaty's cancellation or suspension. The pact may be dissolved entirely in
case of permanent impossibility. On the other hand, if the difficulty in
fulfilling the terms is only temporary, the treaty may be suspended for such
time period as may be considered necessary.
- Significant shift in circumstances
The maxim Rebus sic stantibus states that if the basic or fundamental
circumstances under which the treaty was signed, has changed, then either
party shall have the right to terminate it. Unexpected developments that
have a "fundamental" impact on the treaty may be enough to cause it to be
terminated or revoked.
- In cases where the Relations between diplomats and consular officers are
- Jus cogens
Any treaty that violates a new jus cogens or peremptory rule of international
law that emerges after worldwide assent is presumed to be terminated.
The consequence of such termination or invalidity, as provided under Article
70 and 71, is that unless the treaty expressly states differently or the
parties agree otherwise and a treaty is terminated under its provisions or in
line with the existing convention, the states shall be released from their
obligation to fulfil the terms of the treaty, further this termination shall not
have any bearing on any right or legal status that exists as a result of
formation of treaty, prior to termination. In case of suspension,  the
parties are relieved from their obligation to execute the treaty during the
Some Important Treaties
- The Treaty of Versailles, 1919, signed at the end of world-war 1 at the
peace conference in Paris formally ended the war between Germany and the
Allies. The conference was considered also significant as it was dominated
by the "big four." Clemenceau in particular intended to ensure that Germany
would never represent a military danger to the rest of Europe, and the
treaty included a number of clauses to ensure that this goal was
The treaty was presented to the Germans as a fait accompli. They objected to
the severity of the clauses contained in the agreement especially the "war
guilt" provision and the terms concerning reparation. Some regard the
treaty as not being part of the solution but rather a hasty and furious
rebuke that only caused to prolong and exacerbate animosity while causing
the same issues as before. The effects of the treaty are divided into three
categories: economic, political and military. Despite that, the treaty of
Versailles is a significant event in the world history.
- The Onís-Adams Treaty of 1819, otherwise known as the transcontinental
treaty, addressed a territorial dispute between the United States and Spain.
Through this agreement, The western bounds of the Louisiana Purchase were
determined by the United States and Spain, and Spain relinquished its claims
to the Pacific Northwest. In exchange, the US acknowledged Spanish control
- The Tordesillas treaty, 1494, apparently split the new world between
Portugal and Spain. The goal was to resolve disputes over newly discovered
areas. It resulted in the establishment of a border west of the Cape Verde
islands between the future possessions of Portugal and Spain and ultimately,
the Portuguese were allowed to create a colony there while Spain took
control of the rest of the Americas.
- The Treaty of Paris, which ended the Spanish-American War in 1898, gave
the United States the Philippines, Guam, and Puerto Rico in exchange for
Cuba's independence. This pact marked the beginning of American imperialism
abroad, and it was ratified after a long and arduous process.
The concept of treaties has evolved as an essential source of International Law
and are held in high regard in the International Justice system which can
succeed if they express a high-value norm shared by all the international
persons signing it. They are considered to be the most powerful and enforceable
type of instrument since treaties mostly represent voluntary agreements between
the countries that agree to be bound by them.
However, like all other sources of international law, treaties are not
exhaustive in the formation of international law, it has its own flaws requiring
country ratification and customs taking a long time to develop and evolve.
Regardless, a combination of customs and treaties considerably lowers the
shortcomings of any isolated source resulting in a far more effective source of
law than its constituents.
- Peter H Sand, Mesopotamia 2550 B.C.: The Earliest Boundary Water Treaty,
Institute of International Law, University of Munich, Germany, (Jul 27,
- UN Charter, art 13, "The General Assembly shall initiate studies and
make recommendations for the purpose of promoting international cooperation
in the political field and encouraging the progressive development of
international law and its codification"
- Vienna Convention on the Law of Treaties, 1969, Art 2 cl. a.
- Vienna Convention on the Law of Treaties, 1969, Art 66
-  ICJ 1.
- Anthony D'Amato, Treaties As a Source of General Rules of International
Law, Northwestern School of Law, (1962),https://scholarlycommons.law.northwestern.edu/cgi/viewcontent.cgi?article=1119&context=facultyworkingpapers
- Josef L. Kunz, The Meaning and the Range of the Norm Pacta Sunt Servanda,
Cambridge University Press, (Apr 25, 2017), https://www.cambridge.org/core/journals/american-journal-of-international-law/article/abs/meaning-and-the-range-of-the-norm-pacta-sunt
- Statute of The International Court of Justice, Art 38 cl. 1,
- (1969) ICJ Rep.3.
- ICJ Rep. 1960.
- Vienna Convention on the Law of Treaties, 1969, Art 29.
- Between Great Britain and the U.S.
- Vienna Convention on the Law of Treaties, 1969, Art 9.
- UN Charter, art 102, 1. Every treaty and every international agreement
entered into by any Member of the United Nations after the present Charter
comes into force shall as soon as possible be registered with the
Secretariat and published by it. 2. No party to any such treaty or
international agreement which has not been registered in accordance with the
provisions of paragraph 1 of this Article may invoke that treaty or
agreement before any organ of the United Nations
- The Covenant of the League of Nations, art 18, "Every treaty or
international engagement entered into hereafter by any Member of the League
shall be forthwith registered with the Secretariat and shall as soon as
possible be published by it. No such treaty or international engagement
shall be binding until so registered"
- Vienna Convention on the Law of Treaties, art 31 cl. 1, "A treaty shall
be interpreted in good faith in accordance with the ordinary meaning to be
given to the terms of the treaty in their context and in the light of its
object and purpose.
- Vienna Convention on the Law of Treaties, art 31 cl. 2, "general rules
- Vienna Convention on the Law of Treaties, art 31 cl. 3.
- Vienna Convention on the Law of Treaties, art 31 cl. 4, A special
meaning shall be given to a term if it is established that the parties so
- Dr. S.K. Kapoor, International law and Human Rights, 481 (22nd ed.
Central Law Agency, 2020).
- Jana Maftei et al, Interpretation of Treaties, Research Gate, (Aug
- General Assembly's Competence for the Admission of a State to the United
- Vienna Convention on the law of treaties, art 33, Interpretation of
treaties authenticated in two or more languages
- Dr. S.K. Kapoor, International law and Human Rights, 483 (22nd ed.
Central Law Agency, 2020).
- Treaties conflicting with a peremptory norm of general international law
- Vienna Convention on the law of treaties, art 70, Consequences of the
termination of a treaty
- Vienna Convention on the law of treaties, art 71, Consequences of the
invalidity of a treaty which conflicts with a peremptory norm of general
- Vienna Convention on the law of treaties, art 72, Consequences of the
suspension of the operation of a treaty
- Adam Augustyn, Treaty of Versailles, Britanicca, https://www.britannica.com/event/Treaty-of-Versailles-1919
- Mohammad Khalid, The Treaty of Versailles, Research Gate, (June, 2015),