ABSTRAK Artikel ini mengkaji kewajiban internasional negara terhadap kejahatan agresi dalam konflik antara Amerika Serikat dan Iran melalui studi perbandingan berdasarkan Statuta Roma 1998, Konvensi Jenewa 1949, dan prinsip kewajiban erga omnes. Permasalahan ini menjadi penting seiring meningkatnya ketegangan antara kedua negara yang menimbulkan persoalan mengenai legalitas penggunaan kekuatan menurut hukum internasional. Penelitian ini bertujuan untuk menganalisis pengaturan kejahatan agresi dalam Statuta Roma dan Amendemen Kampala 2010, mengkaji kewajiban negara berdasarkan hukum humaniter internasional dan prinsip erga omnes, serta membandingkan kedudukan Amerika Serikat dan Iran terhadap kewajiban tersebut. Penelitian ini menggunakan metode yuridis normatif dengan pendekatan perundang-undangan dan pendekatan konseptual. Analisis didasarkan pada berbagai instrumen hukum internasional, antara lain Piagam Perserikatan Bangsa-Bangsa, Statuta Roma Mahkamah Pidana Internasional, Amendemen Kampala Tahun 2010, Konvensi Jenewa Tahun 1949, serta Draft Articles on Responsibility of States for Internationally Wrongful Acts 2001. Hasil penelitian menunjukkan bahwa larangan agresi merupakan kewajiban erga omnes yang mengikat seluruh negara tanpa memandang status keanggotaannya dalam Statuta Roma. Dengan demikian, baik Amerika Serikat maupun Iran tetap berkewajiban untuk menghormati hukum humaniter internasional dan menghindari penggunaan kekuatan yang bertentangan dengan hukum internasional. Pelanggaran terhadap kewajiban tersebut dapat menimbulkan tanggung jawab negara serta, dalam keadaan tertentu, pertanggungjawaban pidana individu. Oleh karena itu, penguatan mekanisme pertanggungjawaban internasional menjadi penting guna menjaga perdamaian, keamanan, dan keadilan internasional. ABSTRACT This article examines the international obligations of states regarding the crime of aggression in the context of the conflict between the United States and Iran through a comparative study based on the Rome Statute of 1998, the 1949 Geneva Conventions, and the principle of erga omnes obligations. The issue is significant due to the increasing tensions between the two states, which raise concerns regarding the legality of the use of force under international law. This study aims to analyze the regulation of the crime of aggression under the Rome Statute and the Kampala Amendments, to examine the obligations of states under international humanitarian law and erga omnes principles, and to compare the positions of the United States and Iran concerning those obligations. This research employs a normative juridical method using statutory and conceptual approaches. The analysis is based on primary legal sources, including the United Nations Charter, the Rome Statute of the International Criminal Court, the Kampala Amendments of 2010, the Geneva Conventions of 1949, and the International Law Commission's Draft Articles on State Responsibility. The findings indicate that the prohibition of aggression constitutes an obligation erga omnes binding upon all states regardless of their membership in the Rome Statute. Consequently, both the United States and Iran are required to respect international humanitarian law and refrain from the unlawful use of force. Violations of these obligations may give rise to state responsibility and, under certain circumstances, individual criminal responsibility. Therefore, strengthening international accountability mechanisms remains essential to uphold international peace, security, and justice.