Amidst ongoing conflicts in different parts of the world and the following blatant violations of International Humanitarian Law (IHL), six states and the International Committee of Red Cross (ICRC) introduced a political initiative called “Global Initiative on International Humanitarian Law”[1]. This initiative aims to upscale the global attention on IHL and re-direct the debate concerning IHL on several issues that deserve special spotlight. By 2026, there will be a series of political and practical recommendations issued on seven workstreams, including the need to update contemporary naval warfare. The question then arises: why does naval warfare need an update among other branches of IHL? 

First of all, treaties and several instruments on naval warfare can be traced back to 1907 [2]. There are eight Hague Conventions (VI-XXII) dedicated to it, which include rules on underwater mines, the status of merchant ships as well as protection of the sick, wounded, and shipwrecked. It is noteworthy, however, that these treaties could not address the overwhelming use of torpedos and underwater mines during the First and Second World Wars. The 1949 Convention for the Amelioration of the Condition of Wounded, Sick and Shipwrecked Members of Armed Forces at Sea became the last adopted international agreement that directly governs naval warfare to this date, leaving the development of law led by state practices evident through military manuals. This is when the infamous 1994 San Remo Manual comes into the picture. 

San Remo Manual, finalized in 1994, stands for a compilation of rules formulated by experts to update and clarify gaps left by IHL treaties in Naval Warfare, such as the use of certain weapons, military objectives, and different kinds of maritime zones [3]. As the name tells us, the San Remo Manual is not a legally binding product despite the debate on the customary status of the rules [4]. Legally speaking, states will not bear any legal consequences if they break the rules in the San Remo Manual⎯perhaps also the reason it was made sophisticatedly detailed. This approach reduces the risk of abandonment, offering states an incentive to voluntarily comply with its provisions. 

Still, there have been radical changes in political and technological trends since 1994, which the manual has not addressed yet, e.g., non-international armed conflict and the use of unmanned vehicles and/or autonomous weapons. The International Institute of Humanitarian Law and ICRC are now in the process of reviewing the manual to update the manual and launch its commentaries [5], which will approximately conclude in 2028 [6]. Reflecting the current stance of naval warfare in IHL, it is apparent that we need a state-led initiative. For the same reason that the San Remo Manual is an independent expert and persuasive legal source, states might be reluctant to bow to something they do not agree on. Albeit a new treaty appears unachievable in the Global IHL Initiative,⎯not that it is one of the goals anyway, the international community needs to keep an eye out for what kind of practical recommendations the states involved will produce and whether it would be a good reference for the updated version of San Remo Manual and its Commentaries in 2028.