These applied rules began to diversify and multiply with the growth of communities. These rules, which are applied by everyone in the society, have turned into the rules of law that will be valid for that community over time.

In this respect, it is possible to characterize the term “law” as the whole of the rules that needs to be followed by the people forming the community. With the increase of communities over time, inter-community relations have increased, and the rules regulating these relations have formed international law.

Today, countries have taken the place of communities, and these countries have determined the rules that will be valid among themselves, namely international law.

Nowadays, international law plays an important role especially in determining the foreign policies of states. Governments have to determine their policies in accordance with national interests and international law.

The history of international law goes back thousands of years. Most of the historians take Renaissance Europe as a starting point for legal developments related to international law. In this context, the historical development of international law is examined in 7 main sections.

These are listed as follows;

• Early period: between the states of Umma and Lagash, BC. In the year 2100, the agreement regulating the relations between the two states was signed. This document is considered the oldest document accepted under international law. After this contract written on the rock, it started to make agreements between many states with the agreements made between the Egyptian and Hittite states. These agreements, which were mostly made for the purpose of preventing violence and trading, started to be signed between Muslims and non-Muslim countries with the spread of Islam.
• Medieval and Renaissance: especially commercial law and maritime law came to the force in this period. With the emergence of the concept of nation-state in France, Spain and England, the foundations of international law have begun to be laid.
• 19th century: In this period, especially after the Vienna agreement, international law rules were determined and became widespread in order to protect the interests of the Christian European states.
• 20th century: the establishment of the United Nations revealed the importance of international law and caused it to become a necessity.

After the Second World War, the independence of the colonial states, especially, caused the rules of international law to be more decisive. The most important element in the determination of these rules is that the rules are related to the power of the states. In short, strong states have put forward the rules that will protect themselves against weak states. Today, international law rules have a more egalitarian structure.

It is necessary to accept that international law is in a higher position than national law. This means that states cannot violate international rules relying on their own national law. In this context, in international courts where disputes are heard, decisions are made by taking into account the rules of international law. For example, the International Court of Justice has stated that the rules of international law are higher than the rules of national law in all of its decisions.

The rules of international law are set by the member states. It is an unavoidable fact that powerful states are more decisive in the determination of these rules.

When a state commits and continues acts contrary to international law, it must end those acts and guarantee that such acts will not be repeated. In addition, if the state perpetrating the said unlawful acts has caused material or moral damages due to these acts, it must also compensate for these damages.

The peaceful resolution of international disputes is included in the United Nations agreement. According to this agreement; investigation, negotiation, arbitration, mediation, reconciliation and judicial solution are determined as peaceful solution methods.

Some sanctions are imposed against states that continue to act against international law. The purpose of these sanctions is to end the said actions and ensure that they do not happen again. Embargo comes first among these sanctions, and other sanctions are; penalties and security measures, compensation, invalidity or nullity and cancellation. Today, these sanctions are applied mainly economically and militarily.