سیامک کریمی

To date, the world has witnessed five instances of the use of force against States' nuclear programs: the U.S. response to the Cuban missile crisis (1962), Israel's attack on Iraq’s Osirak reactor (1981), the coalition States’ military strike on Iraq’s alleged weapons of mass destruction program (2003), Israel’s attack on the Al-Kibar in Syria (2007), and most recently, the June 2025 Israeli attack—carried out in cooperation with the United States—on Iran’s nuclear facilities. The attacking States claimed that their actions were justified on the basis that the nuclear programs of the targeted States, having allegedly deviated toward military purposes, had become an existential threat. Regardless of the accuracy of such claims, can the deviation of a State’s nuclear program from peaceful purposes—and even the acquisition of nuclear weapons—be considered per se a threat to international peace and security, capable of justifying a preemptive attack aimed at destroying or halting that program? This article examines existing State practice and, the ICJ’s case law to conclude that although the formerly consistent State practice rejecting such attacks has fragmented, the current divergence among States does not yet permit the emergence of a new exception to the peremptory norm of the prohibition of the use of force.