Introduction: In the age of nuclear technology, no concern is more important than nuclear security, and no action is more provocative or dangerous than the deliberate targeting of nuclear facilities. The foundation of nuclear security lies in effective physical protection of nuclear facilities, advanced oversight of nuclear activities, and international cooperation in response. The international community has developed a body of rules for nuclear security and physical protection of nuclear facilities that are intended to protect nuclear infrastructure from military attack. Despite the emergence of an international nuclear security regime, the history of nuclear energy tells a different story. From the Israeli destruction of Iraq’s Osirak reactor in 1981 to the recent US attacks on Iran’s Fordow, Natanz and Isfahan facilities in 2025, all demonstrate that great powers have tended to resort to unilateralism rather than international cooperation in response to non-compliance with nuclear commitments, and have challenged the existing international order by circumventing international norms in the face of perceived existential threats. The historical record of attacks on nuclear facilities by great powers provides a clear picture of the formation of a dangerous precedent and the normalization of the use of force..

Research Gap and Objective: As a starting point for the present analysis, jurists such as Professor Schachter, Professor Bout, Professor Murphy, Leo Gross and Daniel Bethlehem argue that the development of weapons of mass destruction (especially nuclear) technology that are immediately available and lack traditional warning signals of impending attack necessitates the use of force. However, the broad interpretation of the use of force and the extension of the concept of self-defense in time create a dangerous precedent and circumvent international norms in the face of perceived existential threats.

Methodology: This research, using a descriptive-analytical method and using documentary sources, seeks to answer the fundamental question: What is the legal status and consequences of the United States military attack on Iran's nuclear facilities within the framework of international law?.

Key Findings: The doctrine of preventive self-defense has been explicitly rejected by the vast majority of states; hence, it cannot be considered part of customary international law. Therefore, military attacks on Iranian nuclear facilities in the context of preventive or preemptive defense are completely illegal..

Contribution to the Field: The United States military attack on the nuclear facilities of the Islamic Republic of Iran without the authorization of the Security Council and in the absence of clear evidence of an imminent threat from the Islamic Republic of Iran is a clear example of the use of force and unlawful aggression. Unilateral military actions seriously undermine the international legal order and create a dangerous precedent.

Conclusion: Although the international community has not yet succeeded in concluding and ratifying a binding, universal and specific treaty prohibiting attacks on nuclear facilities, it can be inferred from the rules of general international law, the practice of the organs of the United Nations, the rules and regulations of the International Atomic Energy Agency and the First and Second Additional Protocols to the 1949 Geneva Conventions that an armed attack on nuclear facilities is prohibited. Any attack on nuclear facilities undermines the belief that nuclear infrastructure, especially civilian facilities, should not be targeted in hostilities. On the one hand, in accordance with Article 56 of Additional Protocol I (1977) and Article 15 of Additional Protocol II (1977), this category of facilities is protected and safeguarded by humanitarian law, and on the other hand, we are witnessing an increasing trend of attacks on nuclear facilities under preventive measures and with the justification of preventing further damage and threats in the future. With this approach, some nuclear-weapon states, led by the United States, have upset the initial balance and fundamental principles of the Nuclear Non-Proliferation Treaty by overemphasizing the principle of non-proliferation of nuclear weapons and completely ignoring other principles, including the principle of disarmament and the peaceful use of nuclear energy. This is while the Nuclear Non-Proliferation Treaty emphasizes the equal and balanced advancement of the three pillars of "nuclear disarmament", "nuclear non-proliferation" and "peaceful uses of nuclear energy". Therefore, within the framework of international nuclear law, even if a state's nuclear program is contrary to safeguards obligations and consequently threatens peace and security, no state has the right to establish and apply guarantees for the implementation of violations of safeguards provisions without the permission of the Security Council and under the pretext of the doctrine of non-proliferation or the doctrine of preventive self-defense. Because the authority to determine violations of nuclear obligations is the Agency and the authority to determine threats to peace and security is the Security Council. Arbitrary interpretation of international rules, unilateral implementation of international law, and military action against emerging threats weaken the principle of prohibition of the use of force, weaken the collective security system, weaken multilateral mechanisms, and destabilize the international legal order.

Keywords: Nuclear Facilities, Armed Conflicts, Principle of Prohibition of the use of Force, Aggression, International Humanitarian Law, Self-Defense.