Introduction

The present article deals with the study and review of the theoretical foundations and practical practice of the International Criminal Tribunal for former Yugoslavia and Rwanda courts in dealing with the concept of legal security. Since security, as a situation that brings forth mental and intellectual peace of a person, has legal effects on social relations, it has been attended to by the legal, legislative, and judicial systems of the countries since a long time ago, and the mechanisms for its establishment have been set out to guarantee the fundamental rights of people. The destruction of domestic governmental and non-governmental organizations, especially the judicial system in the two mentioned territories (the former Yugoslavia and Rwanda), highlights the domestic inability of these countries to establish transitional justice and national reconciliation between the militant groups and the survivors and victims of international crimes. These courts were created as a part of the global strategy to end violence and prevent its reoccurrence, establish justice in the mentioned territories, and establish international peace and security. therefore, by anticipating the most important aspects of the protection and guarantee of the fundamental rights and freedoms of individuals (including the accused, suspects,  convicts, victims, and witnesses), the goal of legal security has been made possible to reach.
The main question of the article is, what impact have the mentioned courts had on the establishment of the principle of legal security in the international arena and the relevant countries?

Literature Review

Although many books, treatises, dissertations, and articles have been authored on each of the topics of this research on both the domestic and international stage, the research method of this essay that considers the function of these two international criminal courts in the creation of this principle is unprecedented. Therefore, the following article is new research. finding a solid and meaningful link between the objective criteria of the principle of legal security and the decisions and opinions of the courts in their judicial proceedings is the main innovation of the present research. The purpose of this research is to show the practical approach of the mentioned international criminal courts towards legal security.

Methodology

this research is both an "applied research" and a "fundamental" one in terms of its purpose, results, and use. The research method is "descriptive and analytical" in terms of the nature of the subject and the method of analysis. The data collection has been through library research, i.e., reference to academic and personal libraries, legal research centers, and accessing books, articles, theses, magazines, academic theses, and websites.
Accordingly, We Will Discuss the Following

The Concept of Security in the Domestic and International Arena

In general, security is a situation where a kind of reasonable and proportionate link is between the demands and the possessions of the actors in a political and legal community which ultimately leads to the satisfaction of those actors. The concept of legal security has entered the international arena from the domestic laws of the countries, and various forms of human security have been met with the approval of the most important international documents (such as the Universal Declaration of Human Rights, the International Covenants on Civil and Political Rights and Economic, Social and Cultural Rights).

Sub-principles Resulting from the Legal Security

Although in terms of the diversity of the legal, political, economic, social ,and cultural concepts and trends, it is not possible to present a
fixed ratio and connection between the protection of citizenship rights and legal security, in general, there are legal regulations and legal criteria in the legal system of countries which are not only secondary to the principle of legal security but are also its constituent elements, and in terms of importance in the legal literature, they are interpreted as "principles". What is meant by the sub-principles arising from the principle of legal security is these rules and criteria which can be categorized into the two forms of principles that guarantee the quality of laws (such as the principles of transparency and ease of access to laws) and the principles that guarantee the legal status of individuals (the principles of predictability of laws and the presumption of innocence). The first group is the principles that protect the rights of citizens, And the second group protects the legal security of the citizens against the government’s power and are actually the supporters of fundamental individual freedoms. The stronger the mechanisms of safeguarding individuals’ fundamental rights, the stronger and more stable their security against the government is.
 

The practice of the International Criminal Courts of the Former Yugoslavia and Rwanda in facing the said principles is:

1-3. The principles that guarantee the quality of the laws
These are the principles that contain the components of the laws in expressing the rights and duties of persons. The significant feature of these principles is that not only must laws be clear and understandable to individuals, courts, and states, but they also must be easily accessible. Transparency of the laws and ease of access to them are among the most important principles that guarantee the quality of laws. Not only the compliance of the laws, regulations, statutes, and procedures of the two Criminal Courts to the international standards and human rights has added to the richness of their quality, but also the practical practice of the said courts in removing the ambiguity and clarifying the laws and also facilitating access of users and actors to the rules and regulations has established and increased legal security.
2-3. The Principles that Support the Legal Status of People
These principles are related to the stage of applying laws and regulations. The main function of the aforementioned principles is to maintain the status created for individuals by the legal norms. The principle of predictability of laws is one of the most important of these principles, which are set out in the statutes, rules of procedure, and evidence of specific criminal courts and have manifested in the practice of those courts.
4. Conclusion
In hearing and deciding important cases such as; Tadić, Ekaiso, Hasanović, Blaskić, Simić, Selbići and Delalić, Erdemović, Kernojlač, Milosevic and Berdjanin, The mentioned International Criminal Tribunals have set the ground for the establishment and promotion of legal security at both the domestic level of these countries and in the international arena by clarifying and removing the ambiguity from the laws and regulations, promoting the principle of ease of access = to laws, employing the presumption of innocence principle, observing the international human rights and resorting to customary international norms regarding the extension of laws to former criminal behaviors, and by compliance with the principle of predictability of laws (despite the legal and judicial challenges in this field), while preventing the impunity of the perpetrators of international crimes under their jurisdiction.
Keywords: Legal Security, International Criminal Tribunals, Former Yugoslavia, Rwanda, Innocence, Ease of Access to Laws.