The Iranian Revolution of 1979 marked a turning point in both Iran's foreign policy and its internal political structure, which was influenced by the legal framework of the Shia branch of Islam. When examining the internal and foreign policy of the Islamic Republic of Iran, a common denominator emerges: the significant role that the Shia religious doctrine plays in shaping it. The study of Shia Islamic law remains an under-researched area within the academic field of comparative religious law. This paper seeks to address the academic gap by examining the legal framework and how it has shaped the Islamic Republic's distinctive narrative of resistance, particularly in constructing a coherent ideological and religious justification for its perception of threat against the United States and Israel in the ongoing conflict. Furthermore, analysing the foundations of the Islamic Shia legal system is essential to understanding the concepts of justice, moral-religious duty, and the pursuit of peace from the perspective of this system. The actions of Iran's Islamic Revolutionary Guard Corps in the ongoing conflict will also be examined in light of the Cairo Declaration on Human Rights in Islam, also known as the Cairo Declaration of 1990, revised in 2020, as well as contemporary debates on human and fundamental rights in the international sphere, including international instruments such as the United Nations Declaration on the Right to Peace of 2016. This paper highlights the complex interaction between religious law, state power, foreign policy, and the dichotomy of the pursuit of peace through international law-abiding instruments or the use of force.