In late February 2026, the United States and Israel launched a large-scale preemptive strike—codenamed Operation Grand Fury—against Iran, citing its nuclear threat, and targeted the Iranian leadership. In response, Iran retaliated by attacking Israel and U.S. military bases in the Middle East. It has also moved to blockade the Strait of Hormuz and to impose transit fees, thereby inflicting severe disruption on global energy supply chains and causing economic instability.

The major military actions in this war are widely assessed as lacking a solid basis under international law. The U.S. preemptive strike is controversial, as it was not a response to an “imminent armed attack,” raising questions about whether it qualifies as an act of self-defense. However, it could be considered lawful if justified as a measure to prevent an imminent Iranian attack on U.S. forces stationed in the Middle East following Israel’s strike on Iran. Iran’s attacks on U.S. military bases in neighboring countries likewise constitute clear violations of sovereignty and unlawful uses of force if the host states did not consent to U.S. operations. Attacks on civilian energy infrastructure in neighboring states also violate the principle under the Law of Armed Conflict (also known as International Humanitarian Law) that only military objectives may be targeted. Furthermore, Iran’s blockade of the Strait of Hormuz infringes upon the right of innocent passage established under customary international law, and its attempt to impose transit fees on vessels transiting territorial waters lacks any legal basis.

The U.S.–Iran war presents significant security and policy challenges for South Korea, given its high dependence on external trade and energy imports. The South Korean government should coordinate with like-minded states to reject the imposition of transit fees and call for the protection of the right of innocent passage. It should also consider participating in multinational operations to ensure the safety of international navigation, while adopting carefully calibrated rules of engagement that limit missions to defensive escort and maritime security in order to avoid potential violations of international law. Furthermore, in anticipation of the introduction of independent AI-enabled weapons systems by the Korean military, there is an urgent need for preemptive institutional reforms, such as mandating continuous legal reviews throughout the entire weapons lifecycle, ensuring predictability through simulation, and applying explainable AI (XAI) technologies.

This article is an English Summary of Asan Issue Brief (2026-13).

(‘미-이란 전쟁의 국제법적 쟁점에 대한 검토와 우리나라에의 시사점’)