The Role Of Treaties In International Law.

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What are Treaties?

Treaties are formal agreements, contracts, or written documents binding the two or more subjects of international law to fulfil their promises. The rules concerning treaties between two or more states are mentioned in the Vienna Convention on the Law of Treaties. The rules concerned with treaties between states and other international organizations are present in the Vienna Convention on Law of treaties between States and International Organizations. The word Treaty can be used to describe conventions, protocols, agreements, contracts, charters, etc. However, not all the charters, protocols are treaties. The main difference between these terms is that a treaty is always binding. 

A country’s signature is in general sense sufficient to bind that country. This is more prominent in bilateral treaties. However, in multilateral treaties, a country’s signature leads to its ratification. Treaties do not need to follow a specific format, they usually take the form of a contract. However, it has to be noted that important treaties generally follow the same pattern. Preamble generally provides the names of the contracting parties which form the statement of the Treaty’s General objective. This is followed by the Articles containing the clauses agreed-upon. If a treaty has been made for a specific purpose which has an end date, this date or the time allotted is mentioned. After this, the mention of ratification and its clauses takes place. Treaties usually end with the following statement, “In witness whereof, the respective plenipotentiaries have affixed their names and seals”, followed by the signatures. 

What are the different types of Treaties:

Political Treaties: 

These treaties include Peace Treaties, Alliance treaties, Territorial Cession, Disarmament Treaties.

Commercial Treaties:

These treaties include Traffic Treaties, Consular Treaties, Fishery and Navigation agreements. 

Constitutional and administrative Treaties:

Conventions related to the establishment of international organizations. 

Criminal Justice Treaties:

Treaties related to International Crime and Extradition. 

Treaties related to Civil Justice: 

Treaties related to human rights protections, dealing with copyrights, trademarks, judgments of foreign courts. 

Treaties codifying International Laws: 

Treaties related to the procedure regarding peaceful settlements, rules of war, rights and definition of states etc.1


Treaties form the basis of International law. Treaties are seen as a source for ensuring reliability, stability, and order in international relations.2 They have been the primary source of legal relations between states since the beginning. The Preamble of VLCT emphasizes the importance of treaties in International Law along with its importance for developing and maintaining peace and order. Through years of the rules and procedure of treaty-making, the content of international agreements changed gradually but, the importance of treaties has remained the same. 

The history of international treaties is very long. Friendship and commerce agreement between Kings of Elba and Ashur in the middle of the third century BC is the oldest International Treaty preserved in full text. This was found in the palace of Elba. When we look at the medieval world, there was no concept of States. However, these International Treaties were made on the basis of sovereigns. The concept of treaties in the early middle age was not restricted just to the kings of different sovereigns but was concluded between all positions. The church had the power to act as supra-personal which means above or beyond what is personal. 3 In the history of the Roman Era, international treaties were concluded orally following an oath. The main reason behind this is that treaties were considered to be personal obligations between the contracting parties. The main fear associated with the non-performance of the act promised was that of god. 

Evolution of Treaties

Ancient Roman Era:

People in the early Roman Era believed that God would punish them if they did not perform their promise. In the later middle ages, the procedure has become more formal and sophisticated. Treaties were concluded in front of envoys representing their respective sovereigns. The ritual of having a written document of the contract sealed by the contracting parties has been introduced in this era. A treaty register was provided by the Curia which stated that the church or the Pope would be the supreme guardians of treaties. According to the evidence, treaties of peace and alliance were more compared to those of trade and arbitration. Through statum in foverum principle, we can learn that treaties were given statutory law status. 

Spanish Age:

The act of catholic sovereigns concluding their treaties at their own will demonstrates the emancipation or freeing of international relations from Roman Curia. Treaty between France and Ottoman explains the fact that sovereigns still indulged in international treaties in their personal capacity. Sultan S€uleyman and King Francis I agreed on an agreement that was supposed to last till the death of both the rulers. Agreement of Peace of Westphalia concluded in the year 1648 involving cities Munster and Osnabruck became the first one to pave the path to common European order of peace. Usage of clauses has become prominent. The most common clause included was: Guaranteeing amnesty. Foundation of treaty law based on the concept of natural justice was explained by Hugo Grotius in his work “De iure belli ac pacis libri tres”.4

French Age:

 In this age, the relations between various governments increased rapidly.  Treaties between states mostly concentrated on settling any dispute or bargain including the conclusion of peace, the building of a boundary, etc. Treaties included mentioning the person’s most important and prominent title. This represented the fact that people did not engage themselves personally anymore but, also the territorial entity they represented. 40 years of peace following the congress of Vienna changed the situation of treaties in the nineteenth century. Treaties were now more concentrated on technical and administrative issues. Treaties were now used as a means to regulate fundamental aspects of their international relations. International conferences promoted the technique of codification for collective treaties. Lawmaking treaties and treatises on specific legal transactions were distinguished. Technical innovations such as open treaties, reservations, and general participation clauses were accompanying collective treaties. With the growing independence of states, bilateral agreements also increased. The main reason behind this increase was due to the improvement in technical and economical conditions. In the year 1917, approx 10,000 treaties were in force.


The nineteenth-century has witnessed impressive growth in the written law. The creation of International Organizations through multilateral treaties formed a basis for structural development in treaty law. In the year 1831 first administrative organization was formed through Congress of Vienna with the constitution of “Central Commission for Rhine Shipment”. This paved the path to many other similar river commissions. With the involvement of other states due to the cross-border interference, states realised that they cannot be regulated by one state alone which brought other international organizations into existence. For example: Telegraph Union(1865), Universal Postal Union(1874). In the history of international treaties, most lawmaking attempts were between 1919-1939. Article 18 of League of Nations stated that international treaties should be registered and their publication is necessary for them to have a binding force. Between May 19, 1920, and January 1, 1935, around 3500 treaties were registered with the secretariat of the League of Nations. During the short era of League of Nations, treaty obligations were the most compared to any other period. Although the number of international treaties increased, there was no structure or well-defined law of treaties. Due to the lack of common guidelines for all the governments, the term treaties itself was considered to be vague and treaty law was very unsatisfactory. In the list of possible subjects for codification, League of Nations in the year 1926 included a question, “whether it is possible to formulate rules to be recommended for the procedure of international conferences and the conclusions and drafting of treaties, and what such rules should be”. When the committee’s report was presented before the League of Nations, this matter was seen as a non-emergency matter and was kept aside. On request of governing board of Pan American Union to draw up projects for the codification of International Treaties, American Institute of International law in 1925 came up with a few Treaties which upon a few modifications led to the adoption by Sixth International Conference of American States, on 20th Feb 1928 of the Havana Convention of Treaties. However, this treaty had its fair share of mistakes. For starters, it did not have the definition of the term ‘Treaty’. The convention of the law of treaties drafted by Harvard Research in 1935 helped in clarifying many such mistakes committed by the Havana Convention of treaties. The rules stated were of great importance. 

Codification of International Law:

The importance of codification was first understood during the first world war when the nation of leagues was formed. The general assembly of Leagues of Nations formed a team specifically for this purpose. By 1930, very little progress in this regard was made. Post the second world war, for the codification of International law, the International Law Commission was established within the UN. Sir Humphrey Waldock compiled the works of the three previous special Rapporteurs namely James Brierly, Sir Hersch, and Sir Gerald and added his own work and submitted his final work in 1966. General assembly endorsed the draft and convened their first session of convention in 1968 and the second session in 1969 in Vienna. 

As seen, though the importance of treaties for maintaining international peace and security was established, it was not until the late 1965s that the first codification of international treaty was adopted by the Vienna Conference on Law of Treaties. The Commission devoted 18 years (1949–1966) and 292 meetings to the topic, four Special Rapporteurs prepared 17 reports, before the ILC could complete its task with the submission of its final set of draft articles in 1966.5 


States cannot form or enter into treaties all by themselves. For this purpose, people are selected from every State to represent that particular state and take decisions regarding the same. These individuals are called representatives of the state. In order to make these decisions, representatives should have certain powers. This power or authority is given by either the head of the state or the foreign affairs minister.

This is explained under Section 7 of the Vienna Convention. Accordingly, an individual is considered as the representative of the state, if he/she has full powers or the state has done an activity which indicates that he/she is the representative of the state. 

Head of the government, head of the state and foreign affairs minister are also considered to be representatives of the state. However, they are not vested with complete powers.

Conclusion of bilateral and multilateral treaties differ. In bilateral treaties, representatives are vested with complete powers. In multilateral treaties, in the initial stages, a committee of full powers is formed in which only the representatives who possess full powers are included. These delegates after assessing the treaty give their power to the secretary of the committee. In case, the full power delegate is not authorized to sign the treaty, he has to get permission from his/her state’s government’s permission to do so. 

If any action is taken without the consent of the delegate having full power, it is considered illegal. That action can come into force only after taking the state government’s order.


Post the edits, a final draft of treaties are made and all the representatives of the states are requested to sign the treaty. This reflects that the state has agreed to the treaty. However, not in every case, the representatives’ sign is crucial. For example, for internal Labor Law, the sign of the Director-General of the International Labor Organization is required.

Why is treaty-making important in International Law?

Treaty making is considered to be very important in International Law since the beginning. Treaties give every state an opportunity to put forth their demands, discuss their issues, try and come up with solutions and make laws after considering all the points for the benefit of the situation. Since it allows all the states to put forth their suggestions, it’s perspective is very wide. Further, it lays down a platform to address all the crucial issues in the world. The flexibility provided in making treaties makes it an easier way of forming international Law.6


Treaties are formal agreements, contracts, or written documents binding the two or more subjects of international law to fulfil their promises. There are six different types of treaties: political, commercial, Constitutional and administrative treaties, criminal justice treaties, treaties related to civil justice, treaties codifying international laws. Treaties have always played an important role in International Law. They have been the primary source of legal relations between states since the beginning. During the Ancient Roman Era, treaties were mostly between individuals. Treaties were concluded orally in the presence of the contracting parties. In the Spanish era, the usage of clauses has emerged. In French Era, Treaties started concentrating on technical and administrative issues. Treaties were not just between two or more individuals but between their sovereigns or states. Nineteenth-century has witnessed great growth in written laws. Though the importance of treaties has remained the same throughout, the procedure of treaty-making, contents involved have changed. Nineteenth-century witnessed the creation of international organizations. After many failed attempts, the law of treaties was finally codified. It took approximately 3000 years of treaty-making before the law of treaties was finally codified. It can thus be observed that treaties have always been a part of international law since the beginning. Treaties are considered to be an important part of International Law as these provide a platform to discuss and address the problems in the world. Further, cumulative opinions of all the states are shared on the same platform leading to a better perspective and cure. Since treaties have no certain standards, it is the easiest form of creating International Law. 


1.  Treaty,  Definition, Examples, & Facts, BRITANNICA, May 16, 2020,

2.  Introduction: On the Role of Treaties in the International Law, RESEARCHGATE, May 16, 2020,

3.  What does suprapersonal mean, DEFINITIONS, 16 May. 2020,

4.   Introduction: On the Role of Treaties in the International Law, RESEARCHGATE, May 16, 2020,

5.  Villiger, History of the Convention MN 13

6. Dr. Yubaraj, International Treaties:Features and Importance from International Law Perspective, SSRN, (23, May, 2020),


Anusha Nookala

Student, Symbiosis Law School Hyderabad

Anusha Nookala is a student at Symbiosis Law School, Hyderabad currently pursuing BBA LLB. She is a corporate law enthusiast.  She is an effective and attentive speaker and listener, highly organized and detail-oriented individual. For any Clarifications, feedback, and suggestion, you can reach her at

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