Amid escalating tensions in Iran, U.S. President Donald Trump has specifically mentioned Japan and expressed hopes for the dispatch of naval ships to the Strait of Hormuz. In response, Japan is intensifying discussions about its potential deployment ahead of the Japan-U.S. summit on the 19th. However, the legal obstacles to such a dispatch are substantial. The article outlines two key legal frameworks that must be navigated before any deployment can take place: domestic legal constraints, including constitutional issues, and the legal assessment of possible U.S. attacks on Iran.

The first issue revolves around Japan's domestic laws concerning the deployment of the Self-Defense Forces (SDF) overseas. One possible avenue for action is under the 2015 security-related laws, which would allow for collective self-defense if the situation is deemed a 'threat to Japan's survival.' The government previously highlighted the Strait of Hormuz as a potential scenario necessitating such an evaluation, but internal assessments suggest that the current situation does not meet the threshold for this designation, making actual deployment unlikely.

Another avenue discussed involves classifying the situation as an 'important influence situation,' which would permit rear support activities to U.S. forces, such as supplying ammunition or refueling fighter jets. However, there are restrictions on performing operations in areas where active combat is occurring, leaving the feasibility of Japan's involvement contingent upon careful legal and strategic evaluations. This complex situation underscores Japan's delicate balance of international obligations and domestic legal limitations as it navigates its role in regional security affairs.