In general, ‘Convention’ or ‘Treaty’ denotes, a contract between
two or more independent authorities, relating to or determining the
rights and duties of subjects or citizens of the respective States in one
another’s possessions. In other words, it is a merger of wills of two or
more international subjects for the purpose of regulating their
interests by international rules.
According to Schwarzenberger: “A treaty may be defined as a
consensual engagement which, subjects of international law have
undertaken towards one another, with the intent to create legal
obligations under international law”.
As defined by Oppenheim: International treaties are
agreements, of a contractual character, between states, or
organizations of states, creating legal rights and obligations between
According to Article 2 (1)(a) of The Vienna Convention on the Law of
Treaty 1969, defines ‘Treaty' as:
…“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 its particular designation…
The definition in the Vienna Convention is expressed to be for
the purposes of the Convention and is limited to treaties between
States. The following is an examination of the elements of the
definition of treaty under Vienna convention as supplemented by
customary International law.
International Agreement Concluded Between States
According to Article: 6 of the Vienna Convention-
“…Every State possesses capacity to conclude treaties…”
This provision provides that, states may make treaties, as reflects in
customary international law. Capacity to make treaties is, in fact,
valuable evidence of statehood, and thus any Public International
Organizations or Individuals are not recognized as having the capacity
to make treaties are parties.
In the Anglo-Iranian Oil Company Case, 1952 ICJ Rep. 93, the ICJ
held that- a contract between Iran and the Anglo-Iranian Oil Company
was not a treaty. It is nothing more than a concessionary contract
between a government and a foreign company.”
In Written Form
Article: 3 further states that- “…The fact that the present Convention
does not apply to international agreements concluded between States
and other subjects of international law or between such other subjects
of international law, or to international agreements not in written
Therefore, The Vienna Convention does not apply to oral
agreements, although such agreements are valid under customary
Governed By International Law
• There may be agreements between states (e.g. agreements for the
acquisition of premises for a diplomatic mission or for some purely
• They are regulated by the local law of one of the parties or by
conflict of laws principles.
The notion of an “international agreement” for the purposes of the law
of treaties is confined to one the whole formation and execution of
which is governed by international law.
Intention To Create Legal Obligations
This element of “intention to create legal obligations under
international law” can be found in the traditional definitions of ‘treaty’
by eminent writers, but it is not expressly mentioned in the definition
of ‘treaty’ by the Vienna Convention.
However, from practical point of view, the decisive factor is whether
the instrument is intended to create international legal rights and
obligations between the parties.
In fact, in the case of Aegean Sea Continental Shelf Case, it is held
that, The element of ‘intention’ is included in the phrase ‘governed by
Embodied in a Single Instrument or two or more Related
It is indubitable that, the classic form for a treaty is a single instrument.
However, in modern practice, treaties are made in less formal ways,
such as “exchanges of notes” or ‘exchange of letters”.
An exchange of notes usually consists of an initial note (by one State)
and a reply note (by the other State). In other words it consists of two
The above phrase clearly acknowledges the validity of the increasing
use of such exchanges of notes and letters in modern treaty practice.
‘Treaty’ is the generic term to embrace all types of binding
international agreements. In practice, a number of terms are used to
indicate an international agreement.
The law of treaties cover both formal agreements (treaties,
convention, protocols, charter, covenant, pact, act, statute) and informal
agreements (agreed minutes, exchange of notes or letters,
memorandum of understanding).
In Bangladesh vs Myanmar, the International Tribunal on Law
of the Sea (ITLOS) discussed whether the “agreed minutes” of 1974
was a legally binding agreement within the meaning of Article 15 of
UNCLOS and determined that it was not a legally binding agreement.
Urgency/Importance of Treaties
The importance of treaties is enormous. Some of these can be
stated as follows:
The treaty is the most important source of international law.
All kinds of inter-State transactions are conducted through treaties.
Various international organizations are established by means of
Disputes between States are brought before International courts by
means of treaties.
In fact, bilateral or multilateral treaties could be a good way of
resolving international disparities or disagreements between two or
Therefore, the special importance of treaties in international law does
not need emphasis.
Different Forms of Treaties
The principal forms in which treaties are concluded are as follows:
Heads of States Form: the characteristics are-
drafted as agreement between Sovereign or head of the State;
obligation expressed them as “High Contracting Parties”;
not frequently used in present time;
reserved for special cases of conventions
Salient Cases: Philippson vs. Imperial Airways Ltd.  AC 332.
Example: Consular Conventions.
Inter-Governmental Form: the characteristics are-
drafted as agreement between governemnts;
no substantial difference from the heads of states form;
employed generally for technical or non-political agreements;
Inter-State Form: the characteristics are-
drafted expressly or impliedly as an agreement between states;
signatories are then referred to as “the parties”;
example: The North Atlantic Security Treaty of 1949.
Ministerial Form: the characteristics are-
negotiated and signed between ministers of the representatives
deals more often than not, bilateral treaties;
representatives of the foreign affairs.
Inter-departmental Form: the characteristics are-
Conducted between representatives of particular government departments;
Example: between representatives of the respective Customs
Administrations of the countries concerned.
Terminology of Different Forms of
Over the past centuries, state practice has developed a variety of
terms to refer to international instruments by which states establish
rights and obligations among themselves. In spite of this diversity of
terminology, no precise nomenclature exists. In fact, the meaning of the
terms used is variable, changing from State to State, from region to
region and instrument to instrument. Some of the terms are as follows-
Treaty : the characteristics are-
no consistent rules when state practice employs the terms "treaty"
as a title for an international instrument;
usually reserved for matters of some gravity that require more
signatures are usually sealed and they normally require
Examples: International Instruments designated as "treaties" are
Peace Treaties (Treaty of Paris (1815)), Border Treaties (United
Kingdom–United States Maritime Delimitation Treaties, 1993),
Delimitation Treaties, Extradition Treaties and Treaties of
Friendship, Commerce and Cooperation.
Agreement : the characteristics are-
usually less formal and deal with a narrower range of subject-
matter than "treaties“;
general tendency to apply the term "agreement" to bilateral or
restricted multilateral treaties;
employed especially for instruments of a technical or
administrative character, which are signed by the representatives
of government departments, but are not subject to ratification;
typical agreements deal with matters of economic, cultural,
scientific and technical cooperation;
Nowadays by far the majority of international instruments are
designated as agreements.
Charters : the characteristics are-
“Charter" is used for particularly formal and solemn instruments;
constituent treaty of an international organization;
the term itself has an ‘emotive’ content that goes back to the
Magna Carta of 1215;
Example: well-known recent examples are the Charter of the
United Nations of 1945 and the Charter of the Organization of
American States of 1952.
Conventions : the characteristics are-
The generic term “Convention“ is synonymous with the generic
was regularly employed for formal bilateral or multilateral treaties
with a broad number of parties;
normally open for participation by the international community as
a whole, or by a large number of states;
the instruments negotiated under the auspices of an international
organization are entitled conventions (e.g. Convention on
Biological Diversity of 1992, United Nations Convention on the
Law of the Sea of 1982, Vienna Convention on the Law of
Treaties of 1969.
Declarations : the characteristics are-
the term “Declaration” is often deliberately chosen to indicate
that the parties do not intend to create binding obligations but
merely want to declare certain aspirations. an example is the Rio
Declaration 1992 and the Universal Declaration Of Human
a declaration can however, be a treaty in the proper sense. a
significant example is the Joint Declaration Between The United
Kingdom And China On The Question Of Hong Kong of 1984;
An interpretative declaration is an instrument that is annexed to a
treaty with the goal of interpreting or explaining the provisions of
A declaration can also be an informal agreement with respect to a
matter of minor importance.
Protocols : the characteristics are-
the term "Protocol" is used for agreements less formal than those
entitled "treaty" or "convention”;
generally never in the heads of State form;
Protocol of Signature is an instrument subsidiary to a treaty, and
drawn up by the same parties. Such a Protocol deals with
ancillary/auxiliary matters such as the interpretation of particular
clauses of the treaty, those formal clauses not inserted in the
treaty, or the regulation of technical matters;
Optional Protocol to a Treaty is an instrument that establishes
additional rights and obligations to a treaty. The Optional
Protocol to the International Covenant on Civil and Political
Rights of 1966 is a well-known example.
Procès-Verbal : the characteristics are-
denoted originally the summary of the proceedings and
conclusion of a diplomatic conference;
also mean the record of the terms of some agreement reached
between the parties;
Example: the Procès-Verbal signed at Zurich in 1892 by the
representatives of Italy and Switzerland to record their
understanding of the provisions of the Treaties of Commerce
Exchange of Notes : the characteristics are-
an "Exchange Of Notes" is a record of a routine agreement, that
has many similarities with the private law contract;
signatories of the letters may be government Ministers, diplomats
or departmental heads;
the agreement consists of the exchange of two documents, each
of the parties being in the possession of the one signed by the
representative of the other;
under the usual procedure, the accepting State repeats the text of
the offering State to record its assent;
ratification is not usually required.
Practice as to Conclusion and Entry
Into Force of Treaties
The various steps in the creation of obligations by treaty are-
1. Accrediting of Negotiators with full powers & credentials;
2. Negotiation & Adoption;
3. Authentication, Signature & Exchange of Instruments ;
5. Accessions & Adhesions;
6. Entry into force;
7. Registration & Publication;
8. Application & Enforcement.
A brief explanation of these are as follows-
Accrediting Of Negotiators With Full Powers & Credentials
Having prior decision to commence negotiations with another State or
States, the first step begins with the appointment of representation to
conduct negotiation, along with necessary authorities and full powers
Article : 7 of the Vienna Convention states that-
“…In virtue of their functions and without having to produce full powers,
the following are considered as representing their State:
(a) Heads of State, Heads of Government and Ministers for Foreign
(b) heads of diplomatic missions,
(c) representatives accredited by States to an international conference or
to an international organization or one of its organ…”
Negotiation & Adoption
The appointed delegates are required to negotiate in treaty-making
process, however, they remain in touch with their governments.
Furthermore, they have confidential preliminary instructions and at any
stage, they may consult with their governments owing to fresh
According to Article : 9 (2) of the Vienna Convention-
“…The adoption of the text of a treaty at an international conference takes
place by the vote of two thirds of the States present and voting, unless by
the same majority they shall decide to apply a different rule….”
Authentication, Signature & Exchange of Instruments
According to Article : 10 of the Vienna Convention that, the text
may be authenticated by such procedure as is laid down in the treaty
itself, or as is agreed to by the negotiating states, or in the absence of such
agreed procedure, by the signature, signature ad referendum or
initialling by the representatives of those States of the text of the treaty or
of the Final Act of a conference incorporating the text.
As per enumeration in Article : 11 of the Vienna Convention, a
State can express its consent by way of signature, exchange of
instruments constituting a treaty, ratification, acceptance, approval or
accession, or by any other agreed means.
Under Article : 12 of the Vienna Convention, the effect of signature
of a treaty depends on whether or not the treaty is subject to ratification,
acceptance or approval.
If the treaty is subject to ratification, acceptance or approval,
signature means no more than an authentication of its text (i.e., the
delegates have agreed upon a text and are willing to accept it and refer it to
their governments for such action as those governments may choose to
take in regard to the acceptance or rejection of the treaty).
But If the treaty is not subject to ratification, acceptance or
approval, or is silent on this point, the better opinion is that, in the absence
of contrary provision, the instrument is binding on signature.
According to Article : 2 (1)(b) of the Vienna Convention, Ratification
defines the international act whereby a state indicates its consent to be bound to a
treaty if the parties intended to show their consent by such an act. In the case of
bilateral treaties, ratification is usually accomplished by exchanging the requisite
instruments, while in the case of multilateral treaties the usual procedure is for the
depositary to collect the ratifications of all states, keeping all parties informed of
Correspondingly, under Article : 14 (1) of the Vienna Convention, consent
of a State to be bound by a treaty is expressed by ratification if:
a) the treaty so expressly provides;
b) the negotiating states otherwise agree that ratification is necessary;
c) the treaty has been signed subject to ratification; and
d) the intention of the state to sign subject to ratification appears from
the full powers or was expressed during the negotiation.
The practice of ratification rests on the following rational grounds:
A state requires an opportunity of re-examining the whole effect
of the treaty upon their interests;
May need to prepare public opinion (or some times even
Referendum) for the obligation the state is about to undertake;
According to the constitutional law of many states, treaties are
not valid without some kind of consent on the part of
Parliaments. (E.g.: the US Constitution);
Often a treaty calls for amendments or adjustments in the
Accessions & Adhesions
"Accession" is the act whereby a state accepts the offer or the opportunity
to become a party to a treaty already negotiated and signed by other states.
In other words, Accession is a traditional method whereby a state which
has not signed a treaty subsequently becomes a party to it.
Actually, Treaties frequently provide that, they shall be open for signature
for a certain period, and that after the expiry of that period they shall
become open for accession. In fact, it has the same legal effect as
Accession usually occurs after the treaty has entered into force. The
Secretary-General of the United Nations, in his function as depositary, has
also accepted accessions to some conventions even before their entry into
Entry Into Force
Typically, the provisions of the treaty determine the date on which the
treaty enters into force. Where the treaty does not specify a date, there is a
presumption that the treaty is intended to come into force as soon as all the
negotiating states have consented to be bound by the treaty.
Bilateral Treaties may provide for their entry into force on a particular
date, upon the day of their last signature, upon exchange of the instruments of
ratification or upon the exchange of notifications. In cases where Multilateral
Treaties are involved, it is common to provide for a fixed number of states to
express their consent for entry into force.
For example: The Vienna Convention on the Law of Treaties, 1969, provides for
its entry into force “on the 30th day following the date of the deposit of the 35th
instrument of ratification or accession’.
The United Nations Convention on the Law of the Sea, 1982, entered into force
one year after the 60th ratification, namely on November 16, 1994.
Registration & Publication
Article 102 of the Charter of the United Nations provides that
"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
Treaties or agreements that are not registered, cannot be invoked
before any organ of the United Nations. In other words, a state party to
such an unregistered treaty or agreement cannot rely upon it in
proceedings before the International Court of Justice or in meetings of the
General Assembly or Security Council.
Registration promotes transparency and the availability of texts of
treaties to the public.
The duty of Publication by the Secretariat is performed by
publishing the instruments concerned in the United Nations Treaty Series,
together with lists from time to time of ratifications, acceptances etc.
A failure to publish, however, does not render the instrument
Application & Enforcement
The final stage of the treaty-making process is the actual
incorporation, where necessary, of the treaty provisions in the Municipal
Law of the State parties and the application by such States of these
provisions, and also any required administration and supervision by
In practice, vigilant “follow-up” work is needed to ensure that State
parties do actually apply instruments which is binding to them.