Legal analysis of the establishment of exclusion zones for submarines in Indonesia’s archipelagic sea lanes

The Indonesian Archipelagic Sea Lanes (IASLs) are critical to international shipping and modern global trade, which depends on unobstructed access through vital maritime routes, including archipelagic sea lanes (ASLs). However, these lanes represent a strategic vulnerability for Indonesia as an archipelagic state during armed conflict, particularly when submarines, highly stealthy warships, are allowed submerged passage. This article examines the legal framework governing submerged transit by neutral submarines within belligerent ASLs during armed conflict. It identifies gaps in the existing law and proposes the establishment of an underwater exclusion zone for submarines as a potential solution, assessing its legality under international law. The article draws three primary conclusions. First, there is a legal lacuna regarding the permissibility of submerged submarine navigation in ASLs when the archipelagic state is at war. Second, the establishment of exclusion zones in ASLs by a belligerent coastal state is lawful under international law, although ambiguity remains about whether access for neutral shipping is mandatory. Third, an underwater exclusion zone is legally permissible, provided neutral submarines are granted a means of passage.